Carb Turbo M81 Mclaren- ready to start after 15 years!

[FloridaGrabber]

Congrats

It is a great feeling to bring one back to life, can only imagine if it one as rare as yours.

[theviking]

Congrats!

[JTurbo]

Good deal - how about some updated pictures of the car

JT

[Chuck W]

Good deal - how about some updated pictures of the car

JT

This.

[m81mclaren]

Thanks! Here are a couple of pics and videos of the first start if I did this right.


http://www.youtube.com/watch?v=W8E3btpG7Ek

[bkoons85gt]

Awesome!!!!! YOU CAN HEAR THE EXCITEMENT IN YOUR VOICE.

Glad to see you are restoring such a cool piece of Ford history

[Kevins89notch5.0]

Awesome man, congrats!

[CKJ]

Awesome man, enjoy it!

[The Mechanic]

Any more progress?

[m81mclaren]

Any more progress?

Thanks for asking and I wish the progress was as fast paced as most others on this site! With long work hours, a commute, and two kids with lots of sports interets this is a long term project. My goal for this year is to get the engine rebuilt and reliable to make it to a local Goodguys show this summer with my son. It would be fun to share it with like-minded car nuts who will appreciate the uniqueness and could relate to the early eighties vibe!

I had a few hours to myself so for a quick project yesterday I tried re-gluing the still great shape headliner as it was pulling back from the front and side edges. I got 95% of the way there with the headliner but I could not pull out the backing without damaging it because the roll bar is so tight to the roof. I looked at the rollbar and to remove it i would need to drop the gas tank again which I did want to deal with for now. It was getting late and cold so I glued what I could to get it out of the way. I then took out the stock front seats to attempt to swap in my beautiful correct Recaro's and looked under the carpet for the build sheet but it was not there. I was happy to see how pristine the floor is. Looks like a car with 23K miles should with not a single spot of rust anywhere. Gotta love a truly rust free CA car! As I expected the mounts on the stock Mustang seats will not swap over to the Recaro's so I am back on the hunt for some compatible mounts.

I took it around the block again. It runs pretty damn good now and boosts well but because of the smoke, snooty neighbors and lack of tags I quickly brought it back home. This is gonna be a lot of fun someday.

Next on list to get it truly roadworthy is to pull the engine for a rebuild. Of course when I get there, I will report back to all with lots of pics and I'm sure many questions! I'm a regular lurker here stockpiling as much knowledge as I can and living vicariously through those who make real, interesting progress with their four eyes.

-m81

[79'293stang]

Sounds like a good project!

[m81mclaren]

I took the M81 on a longer drove Sunday. This car pulls really well for such a small engine and old technology! I still have the smokscreen issue and I am confident an experience mechanic could help me diagnose this without pulling the whole engine for a rebuild and hoping the problem goes away with that. Unfortunately, I've called around and I can't find anyone that wants to touch this car! Thoughts? Also, the idle is high and I was able to get it to kick down to about 1,300 rpm's but during my drive it kept rising to when I pulled in my driveway and it was stuck at about 3,800 rpm's. Should I look to the choke or would that indicate vacuum lines? Suggestions?

[KCoker]

Some of the things that cause smoke. Blue is oil, Black is fuel, white is water. Most likely yours is blue. That can be a bad seal in the turbo, bad valve stem seals, or bad rings. You can do a compression check to find out if the rings are bad. Valve stem seals can be done in the car with an air compressor and only cost $30 dollars or so if you do them yourself. The seal in the turbo would have to be rebuilt by a special shop like a diesel repair shop. Maybe this will help. You can also change the pcv valve, that is kind of a stretch as far is fixing the smoke. later Kendal

[Zap's 85 GT]

Are the spark plugs clean? If so, it's indicative of a bad turbo oil seal.

If it smokes all the time and the plugs have oil on them, it may be because of worn piston rings(did you check the compression?)

If it primarily smokes at start-up, then its most likely valve guide oil seals. Plugs may still be oily/black but not as much if it were piston rings.

A super high idle like that is the carb. Is there a choke pull-off on it somewhere that is sticking? Hopefully no one has messed with it in the past. Once the factory choke settings get altered it takes forever to set them again.

[m81mclaren]

Thanks for the suggestions. I'll check compression as a next step and look at my new plugs to see how oiled they are. Sounds like rings as I earlier thought and probably not a stuck valve or something easier!

[neald]

also for high idle check that the carb base to manifold nut are tight, as these loosen quite a bit over time. Also vac leaks are possible. These may not be the biggest culprit, but while your in there you may as well take care of these areas.

[m81mclaren]

also for high idle check that the carb base to manifold nut are tight, as these loosen quite a bit over time. Also vac leaks are possible. These may not be the biggest culprit, but while your in there you may as well take care of these areas.

Thanks for the tip, will check that out.

[m81mclaren]

That is not the same tank as yours. 79-80 tanks are smaller and are not reproduced by anyone that I have found. 79-80 tank straps and the mounts on the car are not the same as the later model cars either.

edit for 79 and early 80 cars a 74-78 style filler neck to tank grommet is required, CJ sent me this after the universal 79+ one they sent me was too big http://www.cjponyparts.com/fuel-tank-to-filler-pipe-seal-1974-1981/p/FPS3/

[KevinK]

Are you going to make it to any of the shows this year?
Knotts in April
Antioch in May
Reno in June

[m81mclaren]

Are you going to make it to any of the shows this year?
Knotts in April
Antioch in May
Reno in June

Thanks, I'll make the Knotts and Antioch shows but not with the M81. Kids, sports, work, commute, and a bum back make this a very slow build. Excuses I know but before I take this out on a long drive I need to rebuild the engine and tranny, brakes & bearings, cooling, etc. Smog testing will be interesting given all the vacuum lines etc. If I had access to an experienced mechanic familiar with this car, then maybe!

[gr79]

http://www.federalmogul.com/en/After...-Differential/

Finally found this old post.
Update on the fel pro paper gasket for the rear axle cover i installed.
The thick paper gasket failed.

The problem:
May 2013:
Too many oil drips on the driveway from 93 Ranger, 7.5 axle dif cover.
Discovered cover had pinholes in it due to rust.

June 2013:
Replaced old diff metal cover this summer. Cleaned all mating surfaces 100%. The factory used RTV.
Installed Fel Pro blue paper gasket on 'new' cover. Installed gasket dry as recommended.

Well, had a leak within 2 months. Oil drip on cement again. Gasket leak?

August 2013:
Removed paper gasket from cover. Cleaned all mating surfaces again 100%.
Went back to black RTV (no paper gasket), following shop manual guidelines on application of RTV to diff covers.
Followed glue set up window time, per tube instructions.
Made sure no gear lube was left in axle to dribble out while installing cover.
Torqued bolts to spec.

Nov 2013:
No leak to date. Dry as a bone.
Staying ,with RTV from now on diff covers like the factory did.

[chalkysexplorer]

So great you got this car running, I've only ever seen 1 M81 and it was awesome!!!!

Just a thought, try running some Sea Foam through the tank but also do the trick where you run half a can through the carby. I do this on my SVO's every 6 months or so and it makes a huge difference. Might not make a difference if you've got shot rings but won't hurt anything.

[m81mclaren]

Yeah there is probably some gunk built up over the years of not running so may try that thanks for the tip. Met a very cool guy at the local GGuy show who is a hardcore Pinto fan and racer. He dropped by to look at the M81 and thinks there is a valve issue and is convinced the block is not the issue. He's gonna drop by again soon and help me with a compression and leak down test to see if we can diagnose the issue. If this goes as planned (!) I will try and pull the head myself and have it gone through. Apparently there is a machine shop not far from my home that has Lima experience so the local contact and machine shop tip is huge and getting me inspired again! Cheers

[KevinK]

If you need referrals on local shops, my buddy Lou has used many of the locals for his SVO and Mecur 2.3 engines.

[m81mclaren]

Ok had a few hours today and have made some progress. Carb has been gone through by a nearby shop I was referred to by a great guy who races pintos. Before putting it back in I decided to pull the valve cover and do some inspecting. It looked pretty clean with nothing appearing out of place or broken. I cleaned up the cover and cleaned off the cork gaskets that were dry and brittle with some obvious leakage. Should I replace with something other than cork? Is there a 1 piece rubber version that works here? Also going to replace all the hoses and if I can find them all the plastic tabs and vacuum tees I broke! Suggestions on a good place to order from that can match things up?