Chris Grayson's (of MC2Racing) Guide to a Reasonably Priced, Street Setup for Handling

Chris Grayson has been involved in Merkur XR4Ti performance for a very long time. He formed MC2Racing to provide quality performance parts t...

Saturday, December 12, 2020

Throwback: Head Porting By David Godfrey

David Godfrey's Article About Head Porting

David Godfrey is somewhat of a legend in the XR4Ti circles, being a prolific problem solver and fabricator, he came up with some good solutions to deficiencies in the XR4Ti platform. In this case, he's documented how he thought about and went through with getting the head ported. 

David no longer maintains his website, so I pulled this out of the Internet archives to give it a new place to live, so people can see it, and take some inspiration from his ideas. 



I proposed to the MCA folks giving this seminar so that perhaps some of the DIY types might have a game plan on a possible way to port their own cylinder head. Hopefully the results of this seminar will be that this individual will be able to act as their own general contractor and be able to oversee the cylinder head rebuild.


I have been tinkering with cars, motorcycles, bicycles, radio control sailplanes, etc, for all my life. I have probably built at least 25 motors, some of them when I was working for a speed shop but most of them for myself. I have never built a motor for my personal use, even on a daily driver, where I did not port the cylinder head. I ran the IHRA points circuit and set 6 national record with a modified compact Pinto. This car had a 2.0L normal aspirated motor coupled to a Doug Nash 5 speed. Prior to that I ran a 67 Shelby GT500 with a boss 351 Cleveland motor. This car ran in what was then called formula 2, B modified, which is a single 4-barrel class. There were restrictions on the amount the motor could be modified, and, of interest to this topic, particularly how much the heads could be modified.


Porting cylinder heads is rewarding but nasty work. Running the die grinder for the amount of time required is a carpal tunnel syndrome sufferer's nightmare. I know cause I have it! As a minimum ear plugs, safety glasses, and a mask is required.

Since March I have ported three 2.3 heads and manifolds and have been to the eye Dr. twice to get particles removed from my eyes. This is with using safety glasses. The first time a shaving got up underneath my glasses. I switched to protective goggles and got a particle in my eye anyway. I think it occurred when I pulled the goggles off and something fell out of my hair. Now I brush out my hair and dust of my clothes before I pull the protective gear off.


The main tool required is some type of grinder. I have used both electric and air powered grinders and my current preference is the air-powered grinder. I have a 110v 1-horse compressor that works fine. It runs all the time, but it works well.

For rough in type work I have several different types of carbide burrs. Note there are burrs for aluminum and steel. Aluminum burrs have fewer teeth. If you use a steel burr on aluminum be prepared to spend a lot of time cleaning the aluminum out. If you use an aluminum burr on steel it will chatter and dull quicker.

I also have several different shapes of burrs on different length stems. I tend to do most of the rough in work with the large "tree" shaped burr.

A couple of old valves have been ground down on the face that I use to protect the valve seats when working the combustion chamber.

I use several different types of cartridge or sanding rolls for the finish work. I tend to use a lot of the 3/8 diameter 60 grit rolls when working the valve pocket. I will go to 180 and 240 grit rolls for final polish.

When you are using the rolls remember that most of the work is done on the tip of the roll. They will were out fairly quickly so change them often. A worn out 60-grit roll does not become a 120 or finer grit roll; it becomes a worn out 60-grit roll. The "teeth" wear down and the cutting action becomes more of a burnishing effect. One can waste a lot of time trying to use a dulled cartridge roll.

The big diameter rolls are handy for smoothing out bumps and removing casting flash. If there is a ridge in the port such as where the mold seams meet the small diameter rolls will tend to fall on one side or the other. The big diameter rolls really do a nice job of making things round.

I also have a couple of different length arbors. The long arbor is used for intake manifolds and working the short side radius. The short ones are used for general work. The disadvantage of the long arbor is it tends to vibrate more, especially with large diameter rolls.

You will see porting kits from places like Summit or Jegs. I would suggest you get your supplies from an industrial supply house or MSC or McMaster Carr. I buy the 3/8 diameter rolls in bags of 100. Also get a roll of emery cloth to use for smoothing the short side radius.


Most of ya'll probably don't remember this, but back in the early 80's both the NHRA and IHRA had single 4-barrel modified classes. In NHRA they called it super modified. IHRA called it formula 2. These classes had restrictions on the amount of cylinder head work that could be done. They would let you match the intake manifold gasket to the head, but the matched area could not extend more than 1/2" into the port. The bowl are could be worked also, but again, the reworked area could not extend into the port more that 1/2" from the valve seat. The combustion chambers could be reworked as needed. It ended up that the main benefits or power increase was due to rework within 1/2" from the valve seat. This holds true for most cylinder heads.

You can see from the head sections I have that the port is very flat, actually it is parallel to the head gasket surface. You can also see how much material there is around each port. The amount of benefit one can get from porting is limited due to the starting point. No amount of grinding is going to transform this casting into a super breather comparable to today's motors. A significant increase can be made, but recognize the limitations of the design from the start.

Port layout

Recognize that no amount of grinding is going make this into a Vtech head, so instead concentrate on removing obstructions to flow around the valve seat. Keeping with the super-modified rules, reworking the port within 1/2" of the valve seat, is not a bad rule of thumb. The 2.3 head is pretty ugly in this area and the main benefits to be gained will occur from working this area.

When Rick Byrnes went to the Esslinger head on his race car he got a 20% power increase using the same valve size and cam. This increase is due entirely to the port shape. In Rick's case he was able to run 20% less boost and get the same power. The overall shape of the 2.3 head has been determined by Ford. All you can do is try to clean it up. Where I live folks have been racing mini-stockers for years with 2.0 and 2.3 Ford motors. I have seen some pretty radically modified heads show up at my friend's machine shop. These include heads that have had steel tubes furnace brazed in place to change the angle where the port enters the head. Some of these modifications had varying degrees of success, but most were a lot of trouble for little gain. This is due to the base, early 1970-'s design of the head.

I tend to leave the intake port shape and general size alone and except for the bowl area just clean it up. You can see from the head sections that there is no a lot one can do to change the port shape. The exhaust ports get more work. I increase the diameter of the port and reposition it upward. I use to do this by hand, but on the last two heads I've done I did the majority of the work on a milling machine. I set the head up and bored the port to 1.375" diameter with the bottom of the diameter tangent to the existing port floor. I took this to a depth of 1.10" into the port. The remainder of the port was worked with carbide tools and cartridge rolls.

Combustion Chamber Layout

The 1/2" valve seat rule of thumb works on the combustion chamber side as well. There are some obstructions that can be removed or blended and some you can't. The main restriction to flow, especially at low valve lift, is the side of the chamber next to the quench area. This restriction gets worse when big valves are installed. Opening this area up is called unshrouding the valves. One thing you can't to anything about is where the cylinder shrouds the valve. A big valve makes the shrouding worse in this area.

When reworking the combustion chamber I put dykem blue on the gasket surface and then bolt it to a bare block. I then reach up into the cylinder and scribe the cylinder bore to the head. This scribe line defines the "stay out zone". I then scribe lines on the head indicating where I will unshroud the valves. The rough in work is done with the small round and tree shaped carbide cutters. I then use the cartridge rolls to blend and smooth all the surfaces.

Intake Manifolds

There are several areas in the intake manifolds to rework. The main problem area is the ports at the head surface are way undersize. Ford did this to ensure there was no obstruction into the port. The manifold can be opened up significantly to match the head.

To transfer the head port shape accurately to the intake I use a template. Do not try to match to the intake gasket! It is grossly oversize. If the head and manifold are matched to the gasket you will end up with a configuration where the charge air will expand and then be funneled back down. The expanding part is not bad, but the squeezing back down is.

I make a template of the ports by taping a piece of card stock to the head and then using an Exacto knife cut out the port shape and a couple of the mounting holes. With the template still taped to the head I bolt on the intake manifold and scribe or cut the template to match the outside of the intake mounting flange. This gives me a good point of reference of where to place the template on the manifold. I then remove the manifold and template, put dykem blue on the manifold gasket surface, align the template and scribe the port shape to the manifold. Using the carbide cutters the intake can quickly be opened up. After grinding on cast iron one can appreciate working with aluminum.

The lower intake has pretty severe projections into the port on runners 2 & 3 where the fuel injectors plug in. I remove these by TIG welding the outside of the manifold and then smoothing out the bumps inside the ports. They cannot be completely removed, but they can be made a lot better. Epoxy such as Devcon or JB weld can be used instead of welding. Both these epoxies will hold up well.

The runner junction in the upper manifold is another ugly area. I gain access to it by cutting the manifold apart. The junction can then be smoothed and the manifold TIG welded back together. Some folks remove runner walls completely. This would not be my choice for a street motor, but if I were to do so I would still cut the manifold apart to make it easier to get to.

Exhaust manifold

The exhaust manifold ports can be enlarged to match the head by using a template similar to the intake manifold. There are some rather nasty corners and bumps to clean up at the port. I do this using the large round and tree shaped carbide burr.

The opening to the turbo needs to be matched to the stainless steel gasket. This is a lot of grinding but well worth it.

One area to look at is the turbo outlet. I open this up to the inside diameter of the down pipe.

Head Rework Process

I mentioned that the purpose of this seminar was to provide the DIY types with enough info to do their own head porting and oversee the machine work. The steps I use are as follows.

1) Disassembly and Inspection

No special tools are required to take the head apart. A valve spring compressor is handy, but not necessary. A large socket and whuppit (hammer for city folk) can be used to remove the valve keepers. Placing the head on a surface with the springs pointing up. Put the socket on the retainers and smack it with the whuppit. The retainers will pop out. Remove the springs and valves and inspect the seats for cracks. Some cracks can be repaired by a method called posting. Not all cracks can be repaired so it's best to get the machine shop to inspect and magneflux the ports. Most cracks will be in the exhaust seats. Have the machine shop check the valve guides also. It's hard to get a feel for how good the valve guides are until the head has been cleaned.

2) Machine shop tasks, first round.

When the head has been disassembled I take it to the shop for the following task's to be performed. I get the cam bearings removed and the head hot tanked or cleaned. The guides are checked and the seats magnefluxed. If guides are necessary they are replaced at this time. The exhaust seats are then cut and seats for the oversize exhaust valves are installed. The intake and exhaust seats are then roughed in for a 3-angle valve job. Also get the intake manifolds degreased.

3) Porting

When I pick up the head and manifolds they are ready for porting. As I mentioned earlier I lay out the cylinder diameter and scribe the combustion chambers. If there is not an bare block available to scribe the cylinder diameter a head gasket can be used but keep in mind the diameter of the fire ring on the gasket is larger than the cylinder diameter. The lines you scribe will have to be adjusted to provide for the proper reference lines.

The exhaust ports can be layed out and either worked by hand or on a mill. If you have no access to a mill the job can be farmed out. I did two heads including set up and cleaning the work area in an hour.

Working the short side radius is the biggest problem. Its hard to get it nice and round. I rough it in as good as possible using the die grinder and then smooth it using what I call the shoeshine method using the emery cloth from the shop roll. I tear the emery cloth into a strip about 24" long and 1/4" wide. The strip is then placed through the port and drawn back and forth in a manner similar to shining a shoe. Any ridges can easily be smoothed down.

When the intake and exhaust ports are done the templates can be made and the port pattern transferred to the manifolds.

4) Machine shop task's, second round.

When all the port work is done the head and valves are returned to the machine shop for the final valve job and cleaning. The seats are cut to the final dimension and the valves are back cut. If an after market cam is used make sure the retainer to valve stem seal clearance is checked. If necessary the end of the guide can be shortened. After the valve work is done the head gasket surface is level cut. If needed the intake and exhaust manifold surfaces can be cut as well. When all machining is complete the head goes back in the hot tank for final cleaning. The head is then ready for assembly.


I hope this has been of benefit to those who would like to do some of the work themselves. If the task seems to large or is to intimidating as a minimum rework the valve bowl area to remove the ridges and sharp edges and then port match the intake to the head and the turbo to the manifold. Even if stock valves are used clean up the valve bowl. I hate to put a number on it, but probably 75% of the advantage of a ported head is due to work in these areas.

Tell the guy at the machine shop what your plans are and most will work with you. If not find a shop that will. I have been doing this for many years and have used several different shops with good results. So be brave and try it!

Wednesday, December 9, 2020

Throwback: David Godfrey's Rear Mount Battery Box for the XR4Ti

David Godfrey's XR4Ti Rear Disc Brake Conversion

David Godfrey is somewhat of a legend in the XR4Ti circles, being a prolific problem solver and fabricator, he came up with some good solutions to deficiencies in the XR4Ti platform. In this case, in an effort to free up engine bay room, as well as improve safety and lighten the nose for racing purposes, he moved his battery to where the rear seat would normally be located. Since this was more racecar than passenger car, the rear seat was removed. As a part of that, he did a great job in relocating cables and starter solenoid as well. 

David no longer maintains his website, so I pulled this out of the Internet archives to give it a new place to live, so people can see it, and take some inspiration from his ideas. 


Tuesday, December 8, 2020

Repost: 1985 Merkur XR4Ti with a naturally aspirated Lexus 1UZ-FE V8

This story starts with an all too common beginning, with someone wanting and obtaining an XR4Ti, but wanting more "push you into the seat" acceleration from the front-engined, rear wheel drive, coupe platform. While the 2.3Turbo Lima-block-based platform can be improved over stock with not a lot of effort and parts, that won't give you "eyeballs pushed into the back of your head" acceleration. Engine swaps are a common conversation, most frequently with the Ford 302/5.0, but some people have tackled more exotic power plants like the always suggested LS, to Ford 2.3l Duratec and others. 

1985 Merkur XR4Ti with a Lexus V8

Craig Thommes had always wanted a Merkur XR4Ti and found one in good condition in Arizona 10 years ago. The factory 2.3 L turbo Lima inline-four was worn out so he rebuilt one with more power. Eventually Craig grew to want more power and dependability as a daily driver.
1985 Merkur XR4Ti With A Lexus 1UZ-FE V8
Craig turned to Jake Reed to work on the solution. Jake has a lot of experience working with the Lexus 1UZ-FE V8 and once the team realized it would fit, it only took Craig one look at the 1UZ power band to decide. To get the engine to work Jake had to make a custom oil pan and custom mounts for the motor, transmission, radiator and fans. He was also able to get the Merkur automatic shifter to work with the Lexus A340E automatic transmission.
A Lexus 1UZ-FE V8 inside a 1985 Merkur XR4Ti engine bay
This car was intended to be daily driven so everything had to run with factory dependability. That required a lot of wiring by Craig to make sure everything works as it should. He also kept the air conditioning because no one wants to sweat on their drive into work in the summer. A Lexus SC400 cluster was installed which gave the dash a factory look and allowed all car’s vitals to be monitored by the driver.
Lexus SC400 gauge cluster inside a 1985 Merkur XR4Ti
Another goal was for the car to pass all California emission tests. Craig was happy to find it passed easily and now sports a window sticker by the California Environmental Protection Agency Air Resources Board.
A Lexus 1UZ-FE V8 inside a 1985 Merkur XR4Ti engine bay
A Lexus 1UZ-FE V8 inside a 1985 Merkur XR4Ti engine bay
A Lexus 1UZ-FE V8 inside a 1985 Merkur XR4Ti engine bay
1985 Merkur XR4Ti With A Lexus 1UZ-FE V8

Monday, December 7, 2020

Throwback: David Godfrey's Rear Disc Brake Conversion with Thunderbird Rotors, Calipers

David Godfrey's XR4Ti Rear Disc Brake Conversion

David Godfrey is somewhat of a legend in the XR4Ti circles. He was one of the first to figure out a bigger front disc brake option using off the shelf discs, as well as a rear disc brake conversion. 

David no longer makes this and his site is no longer maintained, or even available. I pulled this out of the Internet archives to give it a new place to live, so people can see it, and hopefully start making them again some day. 


PS - there are better options out there today, though. Mainly in Tim Spencer's Ford Focus 280mm/11" rotor and compatible calipers. I'll get links and information out here on that as well.

Thanks for your interest in the rear disc conversion brackets I offer. In the past I have provided a copy of the instructions that were included in the Stainless Steel Brake Company's rear disc conversion kit. These instructions are sufficient if you are installing SSBC's complete kit, but more info is needed for the D.I.Y. types. Also, the parking brake cable routing and connection is a bit of a pain to work out even if the SSBC kit is used. Hopefully the info provided will be sufficient to allow for an easy and trouble free installation.

The cheapest rotors to use come from the rear end of a 87-88 Turbo Coupe. These rotors are not perfectly hubcentric on the XR hubs can be made to work just fine by carefully centering the rotor before tightening the wheel or making a .020 thick shim (using shim stock) .2" wide x 7.50" long and placing this shim between the hub and rotor. SSBC will not tell if the rotors in their kit are standard TC or specially machined TC items with a smaller hole to make it hubcentric. Not a big deal anyway.

Rear calipers from an 87-88 Ford Thunderbird Turbo Coupe or 90-92 Lincoln, Taurus, or Sable will fit the brackets that I supply. The interchange manual does not show an alternate listing for the Turbo Coupe calipers but the Lincoln, Taurus and Sable calipers are the same.

Before you buy rebuilt calipers check and make sure of what is included. The local parts stores list rebuilt rear calipers as "loaded", "unloaded" and "semi loaded". Loaded calipers refer to calipers coming with brake pads and unloaded calipers do not. I was not given a specific answer as to what "semi loaded" means. One guy said it comes with hardware but could not tell me what the hardware was.  I asked if the rebuilt caliper included the factory sliding pin mounting bracket and was told it does. When I looked at the caliper they had in stock the bracket was not included. I have run into this before on the SVT/T-bird front brake conversion. If you get rebuilt calipers make sure you ask for "rebuilt calipers, loaded, with brackets". This should ensure you get the entire caliper assembly.

Complete Brake Warehouse (800-581-2339, ask for Brian) understands the terminology and has the complete caliper assemblies in stock. Core charge for this caliper is high and typically runs around $75 each. It pays to go scrounging junkyards for either good rear caliper assemblies or cheap cores.

Brake hoses
I looked at various ways to connect the Merkur XR4Ti hard line to the T-bird calipers and settled on a pre-made stainless steel brake hose, part number 3-21-S-B, from Pegasus Racing (800-688-6946).  The hoses have crimped on ends and are pressure tested to 3K PSI. Brake line adapters, part number 3265-16 (also from Pegasus Racing), are required to go from the XR 10mm flare nut to a -3 AN male fitting.  These parts from Pegasus are cheaper than braided steel XR brake hoses. The stock XR flex hoses and the hard lines attached to the rear trailing arm are discarded. Another source for these is Transatlantic Racing  (770-889-0499, ask for Paul). A description is listed below. Transatlantic will get the hoses quickly if they do not have them in stock. Pegasus will not and will call, maybe, when/if they get them.

Note that the caliper has a unique to Ford 10mm x 1.5 thread pitch banjo bolt thread. If you get your calipers from a junkyard make sure you get the banjo bolts also. CBW has the correct banjo bolts listed under part number H9469 at a cost of $6.60 for 4 pieces.

Caliper brackets
The adapters are CNC machined from 1018 series steel and allow the T-bird caliper to be bolted to the XR swing arm.

Parking brake
In the installation instructions below is a description of how to route the parking brake using the stock XR brake cables.

This is a bolt on installation and the parts install just as easily as the standard XR brakes.

Loosen the wheel flange retaining nut before jacking the car up. Note that the driver's side retaining nut comes off turning clockwise. Then remove the wheel, brake drum, and wheel flange and disconnect the brake line.  Remove the 4 bolts that hold the bearing hub to the trailing arm and then remove the hub and backing plate. Squeeze the 3 prongs on the parking brake cable where it protrudes through the backing plate and remove the cable.

Install the conversion brackets with the caliper mounting holes at the 11 o-clock position on the passenger's side and the 1 o-clock position on the driver's side. Re-install the bearing hub using the stock bolts. Place the wheel flange on the splines and sung down the retaining bolt. At this time you can install the rotor and caliper. Note that the RH caliper is used on the LH side of your XR and the LH caliper is used on the RH side. When installed the parking brake lever should be facing slightly up and forward. The calipers bolt to the brackets with 12mm x 1.75  x  25mm long bolts (now supplied).

The Merkur XR4Ti brake cable can be modified to work with the Turbo Coupe type calipers without using additional brackets.
The brake cable is routed through a hole and grommet on the rear subframe and then secured with a fold over clip on the trailing arm close to the wheel. Remove the cable from the clip and then from the grommet Route the cable back toward the caliper but this time run it between the subframe and body.  After making sure the parking brake handle is in the down position cut the passenger side inner cable wire about 5" in front of the cable mounting clip on the inside of the drive shaft tunnel. Pull the inner cable from the housing and remove the spring from the end of the cable. Re-insert the inner cable in the housing. Remove the driver's side cable and then the spring. Re-insert the cable in the housing and then route it between the sub frame and the body and then around the anchor on the parking brake handle. Position the cable adjuster about 3" from the end of the cable.

Insert the caliper end of the cable through the anchor on the caliper and connect the inner cable to the parking brake lever.  Pull all the slack from the cables and let the ends overlap. Cut the end of the driver's side cable (the end running to the rear) so there is about 3" of overlap. Strip 3" of the plastic covering from the end of each inner wire and splice the together using at least 2 wire rope clips for 1/8" cable. These clips consist of a small U-bolt and saddle and are designed to splice cable together. They can be bought at home supply stores. Tighten the snot out of the clips and then pull hard on the parking brake handle to make sure they do not slip.

An alternative way to make the cables work without cutting is to work the springs from the ends of the cable and make up the length difference by forming the cable in a loop and then securing the loop with the wire rope clamps.


Parking Brake Cable U-bolt Splice

Parking Brake Cable View

Parking Brake Cable, Brake Hose, Bracket, & Caliper

Remove the brake flex hose that goes from the body to the trailing arm as well as the hard line that went to the wheel cylinder. Install the brake adapter fitting on the end brake line on the body. Connect the brake line to the adapter and the banjo end of the line to the caliper using the correct banjo bolts and copper sealing washers.

Rear Brake Hose Routing

Remove the stock proportioning valve and replace it with a length of tubing connecting the master cylinder port directly to the rear brake line. The fittings on the hose are kinda odd so it might be hard to match up. Some have used an after market proportioning valve with success. Perhaps the easiest thing to do is pull the guts from the stock proportioning valve. This is easy to do and works well.  Use the dust shields if you want, but I left them off.

Finished Rear Brake Conversion

Required parts
Item                                              Part Number/Application            Quantity        Source
rear brake adapter brackets                                                                   2                      me!

Turbo Coupe rotor                        87-88     Turbo Coupe                     2

rear caliper                                    87-88 Turbo coupe, 90-92              2                     varies
                                                        Lincoln, Taurus & Sable

Banjo bolt                                       stock Ford or CBW #H9469           2                    varies

brake hose                                     3-21-S-B                                           2            Pegasus Racing
                                                        18" long, -3 AN to 10mm (3.8) banjo         Transatlantic Racing

hose adapter                                  3265-16                                            2             Pegasus Racing
                                                          -3AN to 10mm male                                   Transatlantic Racing

copper crush washers                   3241-3/8                                           4             Pegasus Racing

Throwback: David Godfrey's 94 Thunderbird Master Cylinder Upgrade for XR4Ti

David Godfrey's '94 Ford Thunderbird Master Cylinder Upgrade

David Godfrey is somewhat of a legend in the XR4Ti circles. He was one of the first to figure out a bigger front disc brake option using off the shelf discs, as well as a rear disc brake conversion. He also figured out that the 94 T-bird master was a better option for XR4Ti brakes than, certainly, the early '85-'86 master, and even the improved '87-'89 master.

David no longer makes this and his site is no longer maintained, or even available. I pulled this out of the Internet archives to give it a new place to live, so people can see it, and hopefully start making them again some day. 


David has developed a master cylinder upgrade for the Merkur XR4Ti that utilizes a lighter and less expensive unit from a 94 T-Bird.  Regarding the master cylinder, David writes:

"I wanted to find one with a bigger diameter piston bore if possible as well as a lighter one since the XR cylinder is cast iron. Never liked the XR cylinder as it is heavy and expensive.  Ended up using a cylinder from a 94 T-bird, non-ABS with a 4.6.  The T-Bird cylinder has a 1.062 in bore vs. the XR's 1.00 in. "

Below are some photos highlighting this modification:

94 T-Bird Master Cylinder with adapter plate installed - View 1

94 T-Bird Master Cylinder with adapter plate installed - View 2

Master Cylinder on brake booster - View 1

Master Cylinder installed on brake booster - View 2

Master Cylinder adapter plate and hardware

"The only trick part is the "slug" that goes in the end cylinder where the booster push rod presses on the end of the piston. The slug makes up the difference caused by the adapter plate and the interface between the XR booster and T-bird cylinder."

Master Cylinder adapter kit "slug"

"The brake lines need to be changed as the XR had two ports for the front line where the t-bird only has one. This worked out in my favor as I want to install a line lock (for drag race burnouts) and I need one line common to both front wheels to do this. The rear line was going to be changed anyway since the stock proportioning valve was going to be removed."

Thursday, December 3, 2020

So, you want to buy and install Euro Ford Sierra Mk1 Lucas/Cibie headlights in your Merkur XR4Ti

Soon after buying my first XR4Ti (in the header picture of this blog), I noticed how good the European headlights looked on Ford Sierras, and, when properly fitted, how great they look on the XR4Ti. Here's an example found on the Internet. Based on this, I started my investigation into what it would take to obtain and install them.

First, the differences between XR4Ti and Sierra headlights

The Merkur XR4Ti had adequate headlights when this 30+ year old car was new, using classic incandescent bulbs with deep reflectors to throw light ahead of the car. The XR4Ti also had fairly useless, separate, inboard light pods that were turned on with the parking lights, serving as sort of daytime running lights, given that concept was just getting legs in the late 80s when these cars came out.

Merkur XR4Ti

The XR4Ti's European cousin, the Ford Sierra, received large, one-piece headlight/driving light units, with glass faces. Not all Sierra headlights are created equal however, which I'll get to in a minute.

Ford Sierra RS

Second, what I learned from looking at two sets of Euro lights

There are two manufacturers of Ford Sierra headlights: Lucas and Cibie. 

I have one pair of Cibie housings that came already fitted on a car I bought, and I have one pair of Lucas housings that I bought separately, with the intention of installing them on my original XR4Ti. 

Here's what I think are the differences, based on looking at two separate sets of lights. 


  • originally made for right hand drive (RHD) markets, namely the UK
  • originally available in a wide range of Ford Sierras, from estates, saloons, and 3dr coupes
  • has "city lights" provision, for a 194 blade-style bulb
  • driving lights (inboard "high beams") were optional (if equipped, you'll see an twist opening on the top to allow for placing/replacing the H3 bulb)
  • Plastic reflectors, for both driving lights and main lights
  • Black, wide steel hold down clips for the front glass
  • Uses H4 bulbs in the main lights
  • Connectors allow for turning of each of the lights individually, where/when equipped


  • originally made for left hand drive (LHD) markets, many European countries, and Argentina
  • originally available in  Ford Sierras, also presumably for estates, saloons and 3dr coupes
  • has "city lights" provision, for a 194 blade-style bulb
  • driving lights (inboard "high beams"), takes a very small H3 bulb with one wire
  • Metal reflectors, for both driving lights and main lights
  • Bare, smaller steel hold down clips for the front glass
  • Uses H4 bulbs in the main lights
  • Connectors allow for turning each of the lights on individually; city lights, low and high beams on main bulb have their own trigger, driving lights


  • Same lighting connector, although pins may be missing if no driving or city light options on the housing
  • Same mounting, three bolts on the top, one bracket on the bottom
  • Both Cibie and Lucas left-hand (driver's side in the US) main light reflectors have lost their chrome. I assume this was from sins of the past, cooking the reflectors with high wattage bulbs. Another reason to switch to LEDs. 

Third: Wiring for the XR4Ti, for LEDs

The XR4Ti has two relevant sets of wires on each side of the car, to run the forward-facing lights you use to drive.

1) headlights - XR4Ti uses a 3 wire socket to hold the main hi/lo bulb. Mine were yellow, white and brown (ground).

2) inboard "city"/DRL lights - XR4Ti uses a pair of wires for this, one grey/red (12v, on with parking lights), one brown (ground).

The XR4Ti wiring and headlight switch worked well enough for the stock lighting, with one high/low bulb. Average bulbs, average lighting for the 80s. They didn't plan, however, for this wiring and the headlight stalk to run more than one high wattage bulb, common in the Euro headlights. 

Euro lights = 55W low; H4 high 60/55W. (H83 Hella = 85W, off road only.)

XR = 9004, 65/45W. (9004 Off-road only, 100W/80).

Looking at the other articles (here and here), they were written 10-15 years ago. They all reference using power directly from the battery, and using the factory headlight wiring to run relays, allowing you to drive the most power directly to the lights. In 202x, we can benefit from low power, high brightness LED bulbs in every shape and form factor. don’t need relays and extra wiring to run LEDs. If you still have the super helpful factory “convenience computer”, you may need to wire in resistors to keep the computer and the display happy. 

Euro Lamp Socket (TOP)

  • City Lamp (18ga, grey) --> to have them turn on with parking lights, use factory b/grey (driver side), r/grey (passenger side) from smaller running lamp inboard of original headlamp. For the factory brown wire that runs with each, run the brown to a ground. This solved a dim light issue on my XR.
  • High Beam (14ga, yellow) --> factory white
  • Low Beam (14ga, white) --> factory yellow
  • Driving Light (14ga, yellow) --> either, factory white, or separate switch
  • Ground (16ga, brown) --> use factory brown ground wire

Other Headlight Options:

1987-1993 Ford Mustang housings are bolt-in replacements for the factory XR4Ti headlight housing, which retains the stock inboard running lights. 

Chevy Silverado (year?) housings have also been used.

Wednesday, December 2, 2020

Throwback: David Godfrey's Manual Clutch Adjuster


David Godfrey is somewhat of a legend in the XR4Ti circles. He was one of the first to figure out a bigger front disc brake option using off the shelf discs, as well as a rear disc brake conversion. The clutch adjuster is one of his creations that is still highly desired. This helps preserve the plastic quadrant the clutch cable rides which is prone to break, given the repeated tension the piece is under while being actuated dozens of times every time the car is driven.

David no longer makes this and his site is no longer maintained, or even available. I pulled this out of the Internet archives to give it a new place to live, so people can see it, and hopefully start making them again some day. Last time I saw them being sold they were $120-150/ea.


Thanks for your interest in the Merkur XR4Ti manual clutch adjuster. I have been working on this project for some time and have developed a product that will allow for the clutch release point to be manually adjusted. Benefits of this are cleaner engagement of gears, quicker shifting, and elimination of the failure prone ratchet adjustment mechanism.
Important to the design is to come up with an adjuster that would work for both T-5 and T-9 transmissions and either the XR4Ti or Mustang clutch cable. I can easily come up with a one off solution to fit my car, but when a design has to fit multiple configurations and be installed by a typical XR owner (whatever that is!) the constraints get a lot tougher.
The manual clutch adjuster works by rotating the cable cam through it range of motion. Slight modification is required to the cam and an existing hole in the clutch pedal needs to be enlarged for the adjustment screw. These are simple mods that can be done by that "average" Merkur XR4Ti owner.

A few years ago I conducted a survey on the IMON list of clutch quadrant failures. Of the 30 something reply's I got only one person had a failure of the cable cam. All other failures were either the ratchet teeth or the spring. The pedal mounted adjuster can use the cable cam even if it is stripped.

Contents of the clutch adjuster kit are:

CNC machined aluminum Clutch Pivot assembly

Pivot trunion assembly with set screw
Pedal trunion
Adjustment Rod
Lock Nut

Installation instructions
The clutch pedal needs to be removed to install the clutch adjuster. The best way to do this is to remove the whole pedal assembly from the car. This task sounds a lot worse than it is.

Begin by removing the sound deadener panel, lower steering column cover, and lower dash from the drivers side. Release the clutch cable by pulling up on the pedal to disengage the ratchet. The end of the cable can then be pulled from the cable cam. From under the hood pull the cable from the guide tube. The hardest part is now over! 

Remove the spring clip from the end of the brake booster rod where it comes through the brake pedal. Remove the connector from the brake light switch or the entire switch by twisting it 90 degrees and pulling it from the bracket. If you XR has cruise control disconnect the hose to the vacuum switches.

With the above done the pedal assembly is ready to unbolt and remove. There are two 17mm nuts where the pedal bracket meets the firewall. You will have to pull the carpet back to see them. Remove the nuts and flat washers. There is a 12mm-headed bolt going up from the pedal bracket to the dash support structure. Remove this bolt and the pedal assembly can be removed. With the clutch pedal assembly out make sure the nylon bushing on the end of the brake rod does not fall off and get lost.

With the pedal bracket out you can see a big hair pin type clip that holds the clutch pedal on the shaft. Remove this clip and the two nuts that hold the guide tube to the pedal bracket. You can now remove the pedal from the shaft.

Remove the clip from the end of the rod that holds the ratchet in place. Remove the rod, ratchet, and ratchet mousetrap spring. Disconnect the large spring to the cable cam and discard. Remove the cable cam from the pedal.




Using a hacksaw, sharp knife, or side cutters, remove the tab from the end on the cam as shown in the picture. Make sure the tab is completely removed and flush with the flat surface.



Place the clutch pivot on the cam and press the pre-installed roll pin in place. The cam is now ready for installation. The roll pin can easily be pressed into place using a bench vise or channel lock type pliers.


The pedal needs to be modified so the adjustment rod can be installed. There is a small slot on the front of the pedal near the pivot. Drill the slot out with a 1/2" drill. It was easier to drill the hole if the slot is made somewhat round by using a rat-tail file. When the drill is through the pedal rotate it slightly up to elongate the hole. Remove any burrs with a round file. The spacer needs to fit in the hole and be able to rock up slightly.





Place the adjustment rod through the spacer and then through the hole in the pedal. Thread the pedal trunion on the adjustment rod with the flat side of the trunion facing away from the pedal. 


Place the pivot trunion in the clutch pivot. Place the cam in place on the pedal and turn the adjustment screw in until the end engages the pivot trunion. Snug up the set screw using a 1/16" Allen wrench to engage the groove in the end of the adjuster. The set screw does not need to be tightened down on the adjuster, but just engage the slot to keep the adjustment rod captive to pivot trunion.



Place the pedal assy on the shaft and install the guide tube and the big hairpin clip making sure the clip is fully seated in the groove on the shaft. The shaft is spring loaded so it can be pressed out to make putting the clip in place easier. Install the clip before tightening the nuts on the cable guide tube. Turn the adjustment screw rotating the cam to the forward position.

And now, the most famous instruction, "installation is the reversal of removal."

With the cam rotated all the way forward (adjuster rod fully extended from the pedal) place the clutch cable through the guide tube and hook the end over the cable cam. Turn the adjuster screw to tighten the cable and set the release point. When satisfied with the adjustment tighten down the lock nut making sure the spacer is properly engaged in the pedal trunion. Install the lower dash and other parts. Once installed the clutch adjuster can easily be reached from the foot well area.