SMF Ford Probe - F2T and Other Oddball Mazda Content

Alternate title: The Car Everyone Has A Joke About

Well, I've lurked this forum for some time, but I've never registered. I've recently been convinced to post my build here, so I'll provide some background first.

The car is a 1991 Ford Probe GL. The MX-6's slightly tubbier cousin. The GL was the base model, equipped with an earth-shattering 110hp/130lb·ft Mazda F2, fed to the ground through an equally utilitarian Mazda G-type transaxle. It makes for a light-ish, torquey-ish, fun-ish car with absolutely no straight line power.

I've autocrossed the car for a few years, the suspension has been in a constant state of change, but now I've gotten it to a point that it's fairly well sorted, but I'll include some highlights just for everyone to get a feel for what I'm starting with. Dampers are custom valved KW V3s, the car is on reinforced FD wheels wrapped in 225/45/16 ZII's, poly bushings throughout, addco 1" solid front bar, Probe GT rear bar, camber plates front and rear, MX-6 rear strut tower brace, AWR front strut tower brace, etc... I've built a very capable handling platform considering it's weight and suspension design handicaps.

Anyways, the car has very little power. The engine remained largely stock, I did change a few things, but I made ~125hp on a good day. I want more power. I tossed around high compression N/A motors for a while, but if I ever do that, I'd like to build a full on FE-DOHC race motor, and I don't want to commit to a foreign motor with E36 M3 parts availability just yet, so I've decided on a turbo F2.

This is going be a lot of copy pasta from another forum to get the thread going, so please forgive me.

The plan is to build a reliable >300HP capable motor that will regularly see 6000rpm+. I don't want to be ripping this thing out of the car again next year because I tried to cut corners.

The basics include:

9:1 CR Forged Pistons - Stronger, lighter than stock, I don't think I need to go too in depth here.

Pauter 4340 Rods - Rated to more power than my turbo is capable of - I can go crazy in the future without stock rods being a weak point

Borg Warner S251 Turbo - Slightly smaller than the largest S200 family turbo - Modern turbine and compressor geometry - Compressor map is about perfect for the F2 - Supports 500+hp - Exclusively oil cooled, less for me to worry about, stock water feed can be used to cool the wastegate

Everything else is really just going to be there to make everything work together. I will be retaining the stock ECU for the time being, simply to allow me to work out all the other issues first, rather than trying to tune a set up that may change.

This thread is going to be less of me looking for advice (although I'm sure I will ask from time to time) and more just a record of my build.

I'll do my best to shine some light on things I'm doing that are "race" engine specific that wouldn't be required in most cases, in case anyone wants to use this thread as a guideline.

Anyways, here's what I have to start with:

[URL=http://s15.photobucket.com/user/jamesjozef/media/4450EBDD-1BF8-4ED3-9FA9-ED7DD9D42FAC.jpg.html][/URL]

[URL=http://s15.photobucket.com/user/jamesjozef/media/855027A6-BEF6-4F25-BA82-A3F2EEC6FABB.jpg.html][/URL]

[URL=http://s15.photobucket.com/user/jamesjozef/media/4526BB07-2769-4A20-992F-9373D66FD2F6.jpg.html][/URL]

Copy Pasta #2:

Anyways, I took the classic "turbo comparison" picture today: [URL=http://s15.photobucket.com/user/jamesjozef/media/3C810A5F-C7DD-42C8-883D-F9698D63237D.jpg.html][/URL]

Some more pictures of the process: [URL=http://s15.photobucket.com/user/jamesjozef/media/3259A5A7-324C-4AB1-AAEA-BBC6D9EEEA66.jpg.html][/URL] [URL=http://s15.photobucket.com/user/jamesjozef/media/D0779A1D-78EB-4FF7-A333-A2807EDA6672.jpg.html][/URL] [URL=http://s15.photobucket.com/user/jamesjozef/media/1EAF2C46-2441-4C15-ADA8-28CE01637C7B.jpg.html][/URL] [URL=http://s15.photobucket.com/user/jamesjozef/media/E1DC6BAD-6B2B-4F72-89EB-7033BC1150BF.jpg.html][/URL]

I found some unusual wear inside the upper timing belt cover: [URL=http://s15.photobucket.com/user/jamesjozef/media/E58E5483-A3D8-403E-AE0A-EDA73ABD637B.jpg.html][/URL] Heat related? Anyone else have anything like this? My other motor did not do this.

Oh, and the mythical oil pan gasket reared its head. It seems Ford calls for an RTV-Windage tray-RTV-Oil pan gasket-Oil pan combination on the bottom of the block. [URL=http://s15.photobucket.com/user/jamesjozef/media/C654DA80-6F84-4FC1-B95E-F3766CB8AC93.jpg.html][/URL]

Anyways, I've been busy as always, I swear there's a mega update coming soon, but here's a picture of my current project, bonus points to anyone who can identify everything going on here vs. stock: [URL=http://s15.photobucket.com/user/jamesjozef/media/DDE4159A-6E44-4ED9-BFA2-59D9F1D740D7.jpg.html][/URL]

I don't know how many hours I have in to this head so far, but it's taking a while. The exhaust side of the casting has a lot of irregularities. No two ports are the same, or even close. Short side radii all differ, spark plug inclusions are different sizes and shapes... But I've got all the intake ports done, and 2 of the exhaust ports to where I can call them acceptable. I've got one chamber done, but I'm taking my time there, as I need to decide the best way to attain equal chamber volumes, as there's a little more variation than I'd like in the casting.

Picture relevant: [URL=http://s15.photobucket.com/user/jamesjozef/media/CFF71C43-3280-498F-BEEC-0F74417E6E9A.jpg.html][/URL]

If anyone has dealt with these heads before, the intake side is very well thought out, the casting is of above average quality, and very pleasant. The exhaust side is just the opposite.

I'll update with non-copy pasta in the next few days. I have a block thats waiting for a baffled oil pan, and a head I need to get out in to the garage and finish porting right now.

All banter welcome.

• James

Timing belt cover is interesting.... i have an F2 that has timing covers that look like they were microwaved. Melted holes in them, sagging and totally deformed everywhere.

Motor ran fine. No signs of any extreme damage anywhere. Puzzling, really.

Welcome to the madness!

This thread is pertinent to my interests. I love F2Ts and cant find one, plus concealer never updates so I cant get my F2T fix, will definitely be watching this one.

Sorry, sir. Hasn't been much going on, just waiting to put the new motor in.

James is doing far more to his car than i ever will, though. This is how it SHOULD be done.

Well... I don't have 2 (3?, 4?) miatas on the go, a KL powered Escort, or multiple MX-6s, so I'd hope my one race car/project vehicle/uncompetitive hunk is built to a decent standard.

Hell, I haven't even purchased a parts car for it yet. The Volvo I drive daily and spend as little as I possibly can on has a parts car.

I just have to go clean up one spark plug inclusion a little more, and smooth out the floor of one port and the exhaust side is finally done. I had to remove so much material that it took a lot of patience to get all the ports to look the same. I almost had too much freedom. I'll update later tonight.

• James

I'm hoping to join the F2T fan club soon...this will be good!

I know, I know, I don't update. I've been dealing with a bruised tail bone this week, so I've had lots of motivation to stand at the workbench rather than sit at the computer.

Here are a few quick pictures of the head in progress. I'm finishing all the chambers and hopefully the intake ports tonight.

More to come!

• James

Alright, I'm taking the head to the machine shop on my lunch break today. While I'm waiting for it back, I'll be opening up the transaxle and installing my LSD.

Not to get ahead of myself, here's some assorted pictures/insight from the last few days of work:

My head was one of the better castings I've seen, except for here maybe:

Notice the cam bearings, specifically the dowel pins One of these things is not like the others Yep. The cap was tightened down with only one dowel pin. I'll thank the bolt and cap design on this head for somehow centering it, because the wear looks more or less normal Good job on the machining here, mazda...

And a glamour shot to finish things off.

Head is now at the machine shop.

More to come!

• James

Nice looking work!

Following, this as its has info pertaining to my interests...

MOAR UPDATES NOW, JAMES!!!

You're totally going to run this on an E-manage, right?

Alright, alright.

The head is still at the machine shop, but I've seen it and it's almost finished. Much excite.

The valve springs I'm using didn't install at advertised seat pressures, so there was some additional machine work to be done, as well as discovering that the head had eaten the exhaust valve keepers, FE DOHC style, so I'm still waiting on those from Mazda, they should be here tomorrow.

In the mean time, my interests have kind of shifted and now I'm in to trannies.

...Horrible jokes aside, I am an MFactory dealer, and I've set about installing my LSD from them. I'll have a more in-detail update on this when it's done, but I just cracked the case open today, so this is all for now.

This fcucking lock nut is 38mm. Also an impact socket is too thick, and hits the gear before it can grab the nut. The more you know.

Oh, and fun fact, I have a Ford built Mazda transaxle, so it has metric AND SAE fasteners! It's like working on my Volvo except this one is supposed to make sense and not be pulled together with parts from every european nation.

Once that lock nut is off, and you go and buy yourself some proper roll pin punches, you get this to stare at. (I also dropped a detent ball in there... I'll need to find that)

...and you find this on the magnet along with all the filings. I'll need to figure out what caused this. At least it isn't a gear tooth as it originally appeared while covered in muck.

For being the "pinnacle" of Mazda transaxles, it's pretty damn simple.

That's all for now.

• James

Well, Mazda is dropping the ball big time on ordering my valve keepers. In other words, I don't have my head back yet.

I do, however have my ring gear back from being separated from the original differential and it is now on my LSD. Getting so close. I will update next week for sure.

I just spent the last three weeks fighting with a differential that wasn't quite made to the right specs in my VW racecar build. Hopefully yours goes off without a hitch.

Well, I wish you hadn't said that. My diff had a machining issue with one of the holes or bolts, and I'll let the pictures speak for themselves. The transmission is on hold until the replacement diff arrives. http://i15.photobucket.com/albums/a360/jamesjozef/B4120814-D19F-41AA-A6BC-DC8FAC7F893E.jpg

I did however, finally receive my valve keepers from Mazda, though they were over a month late. That means the head is back. The new dual valve spring install with 75lbs of seat pressure, over 48lbs stock, so these should help keep the valves where they should be under boost.

Mocking up the exhaust flange on the new M10 exhaust studs

No spark plug clearance!

Now, before I get this head back together, I need to clean my rockers and rocker shafts. What have you guys found to be the best method for that? What solvent should I use for the burnt on oil/sludge on/in them? Can I just leave that soak in a big tupperware container or will the solvent be too harsh for the plastic? This is my first engine build, so I'm still learning, especially with all the small/unglamorous details.

• James

Buddy of mine is doing this on a really gross 3sgte head.

Says Coke is working really well.

Well, I screwed up. I used "Super Clean" to clean my head pieces. Great cleaner, cleaned the steel pieces really well, and very quickly.

However, it appears that I left my aluminum pieces in it too long. This is a matter of minutes. One minute the rockers were cleaning up nicely, the next they have a chalky, etched appearance. I left them in while I was cleaning the cam caps, as I knew the caps were aluminum, yet forgot the rockers were.

It also appears as though I may have left the caps in too long. I don't know what my bearing surfaces looked like before, but now 2 of the caps are dull on the bearing surface, with some shinier spots where I assume, more oil varnish was built up.

Can I polish these aluminum bearing surfaces in some way? If I just replace all the caps, the centerline on the new caps should be the same as the head, and as long as my clearance is correct, I shouldn't have any issues, right?

Anyone have any input going forwards?

The plus side is that now my cam and rocker shafts are squeaky clean.

Update time!

Race season is almost upon us. For me it starts on Sunday, so that means fixing some little issues with the car.

I have some sort of module/relay issue with the right turn signal that I need to troubleshoot further.

I also have no blower motor currently. That's a resistor issue, but I don't have a spare, so I'd like to locate one before Sunday, otherwise the 2hr drive to the event will be chilly.

I have, however already installed my new master cylinder. No more somewhat inconsistent pedal feel this year.

I also compared an FC VAF next to my stock unit to see if it could be an upgrade in any way. Turns out, not so much. It's the same body casting with a different sensor. Any miata guys want to take this off my hands?

I also started putting my head together... The top and bottom end will meet some day.

Pics relevant:

I need to clean some of the unnecessary crap out of here in the near future...

Any updates?

Very soon there will be! Lots has happened, lots that delayed everything.

This was my "air freshener" on the way home today. Bonus points for knowing which vehicle it's hanging it.

Looks like maybe a Turbonated Volvo?

Not turbobated. Not just yet. It's getting a hotter cam very soon, but that's a different build thread.

Well, all my head parts have showed up. It's together! I'm waiting on borrowing an accurate torque wrench to tighten down the rocker shaft/cam cap bolts, as I think mine is on the high end and I don't want to risk it. Too and bottom end may meet this weekend. After that, I just have to verify valve clearance is good at the intended timing I want to run, and the assembly can begin!

Pic relevant.

Yes, the exhaust ports are huge. Yes the exhaust studs are probably overkill at M10. More real updates soon.

Does anyone have a spare F2 crank pulley? Mine was damaged during removal.

That's definitely a Volvo 240 dash.

Also, why no pictures of the actual Probe?

I've been meaning to post some from events this year, but I guess I'm just not photogenic? I don't have anything recent really, so enjoy this from 2 years ago. All that's changed is the tires, and the damper/spring combo, so it still looks much like this.