FuzzyDunlops Toyota MR2 MK1.5 build thread.

[FuzzyDunlop]

Found a mistake I was making with tuning. I was setting my injector Dead Times (Lag Time) to high. According to the SARD Website these 800cc Dark Blue injectors should be at 0.750msec when I had them running up at 1.150msec. This was creating very low Volumetric Efficiency numbers at idle, like 7 to 8. Since the switch I now idle at around 28-35 VE and it is MUCH smoother.
Also the car has more pep. This may actually have been a major error I had even with the 400cc injectors. 10PSI right now feels REALLY good. Im going to work on Acceleration Enrichment tonight and then I may start bumping boost up to 13-15 psi as well if everything is holding up.

This is fun.

As for the clutch, I have been babying it a bit. I have 300km on it so far, and will put another 300 before I start beating on it like a red headed step child. But it feels good so far. Just like OEM. I had to adjust the clutch pedal height slightly to allow a little more travel to get disengagement, but no problem there.

Also, this transmission shifts buttery smooth. The only issue is a slight grind when I try to put it into reverse. But I found if I put it into 4th first, then move to reverse it barely grinds.

So all in all, things are on the up and up.

 

[JCH13]

Good job catching your tuning mistake, those can be the worst this to diagnose.

 

[FuzzyDunlop]

I think my headgasket is toast.

I still have a random overheating problem.

I have an oil leak that I can not pinpoint from a seal, and may actually be coming form between the head and block.



What the test here? Leak down? Compression was good last I checked. What other tests could I do to check head gasket?

 

[JCH13]

I think my headgasket is toast.

I still have a random overheating problem.

I have an oil leak that I can not pinpoint from a seal, and may actually be coming form between the head and block.



What the test here? Leak down? Compression was good last I checked. What other tests could I do to check head gasket?

I'd do a leakdown and test coolant for combustion products. You can do a leakdown test with the piston at BDC, this will also check for leaks through cracks in the cylinder wall. You can also hook a hose onto the radiator bleed nipple and check for bubbles as the car is running.

HGs aren't TOO bad, if you're fairly uncertain about the HG health it might be best to 'diagnose through treatment.' Anything in this motor's history to indicate a likely failed HG or similar?

 

[jlee]

Cometic MLS head gasket and ARP studs!

 

[FuzzyDunlop]

There was that one time last year when I broke a shift cable and had to drive home in 2nd gear the whole way. I think I boiled it over that day and thats what may have caused a blown gasket which has just been getting worse. The car gurgles after I park, but I thought maybe that was normal. Ill find a Leak Down tester and do that soon.

Like you say H/G isnt too difficult. Looks like it should only cost about $300 if I do all my own labor. A few question though.

Do I HAVE to get the block decked?

If I go MLS head gasket I need to get the head flatted. Apparently MLS are more prone to failure without perfect surfaces to mate. Some other (like OEM) gaskets would be more forgiving and do the job just a well.

I may get the Head Gasket Repair Kit from TwosRus. The gasket has a 0.040" thickness; will that screw up my compression ratios? How much do compression ratios matter?

Also, In order to get the head off I believe I need to remove the cams to reach the bolts. Do I need to buy new cam bearings, or should I be able to reuse them. Getting new bearings would mean re-shimming as well... this is start to add up in $$

Another option: there is a guy selling a Gen3 engine (sans tranny) near me. Its JDM and has 57k km. He wants $2000 for it though... but it should be a pristine engine. Maybe thats bit much...

 

[jlee]

You have to re-use the cam caps - they are line-bored through the head and they are not replaceable unless you were to line bore it again to ensure perfection.

I had my block and head inspected, cleaned, etc., but I also did a full rebuild. If the block is flat, you should be okay with cleaning it and putting it back together.

I would go MLS because strength, but if you want OE-safe-ish power levels, you could run an OE gasket. I have one I can bring up with me on Friday...I'm not sure if we'll be able to connect when I'm in town, but it'd probably be cheaper to get it to you from Canada than from here anyway.

$2k without transmission is a lot for a gen3.

 

[FuzzyDunlop]

oh I see. Cool!
This shouldn't be too difficult then. Ill have to drop my engine again ... which sucks... but I dont have the room in the bay to do this. Too bad I didnt know about it a month ago.

Dont worry about bringing the gasket. Ill get Daves kit if I need it.

And yeah, friday evening is not looking good for me at this point. Really too bad, it would have been fun to meet the inspiration.

 

[jlee]

We'll be leaving early Saturday morning - haven't talked to her about stopping in Edmonton on the way yet, but if you happen to be up there, maybe we could grab a coffee or alternative.

 

[JCH13]

You don't need to get your block decked, at least not unless it is warped. I have a decent machinist-grade straight edge and some feeler gauges that I used to make sure that my block was good.

All you ever wanted to know about 3SGTE compression ratios: http://www.mr2oc.com/showthread.php?t=366753

Will it screw up your compression ratio? Using a 0.040in gasket vs the OEM 0.056in gasket will give you a compression bump.

How much does it matter? Well, it depends on how aggressive your tune is. Higher CR -> more prone to knocking. Going from 8.5:1->9.0:1 CR isn't a huge step, but it is probably enough to warrant going through your fuel map, and maybe spark map, again.

A higher CR will (very generally) give you better off-boost performance and better fuel economy at the possible expense of on-boost performance.

You should be able to re-use your cam bearings unless they are worn out of spec.

And yeah, friday evening is not looking good for me at this point. Really too bad, it would have been fun to meet the inspiration.

Never meet your heroes!

 

[FuzzyDunlop]

Did a compression test and it read 180 across the board when the engine is hot, dry, and throttle open. Didnt bother doing a wet test because the dry numbers were solid.

I then went for a short drive. Pressure built in the coolant lines and temperatures went up to 200*F. After shutting it off I noticed the coolant reservoir was gurgling. I was curious to what exactly was going on, because I didnt boil the fluid, so I took the cap off and looked inside. Pressurized air was coming out of the overflow hose from the rad cap. So air is entering and pressurizing the system somewhere, somehow. The only thing I can think of being the culprit would be the head gasket or somehow the turbo coolant lines.

 

[JCH13]

Did a compression test and it read 180 across the board when the engine is hot, dry, and throttle open. Didnt bother doing a wet test because the dry numbers were solid.

I then went for a short drive. Pressure built in the coolant lines and temperatures went up to 200*F. After shutting it off I noticed the coolant reservoir was gurgling. I was curious to what exactly was going on, because I didnt boil the fluid, so I took the cap off and looked inside. Pressurized air was coming out of the overflow hose from the rad cap. So air is entering and pressurizing the system somewhere, somehow. The only thing I can think of being the culprit would be the head gasket or somehow the turbo coolant lines.

That does scream "head gasket" to me. The turbo coolant lines shouldn't be anywhere near pressurized air, and if they were you'd have a cracked turbo center, which seems unlikely.

When you have the engine apart I would strongly encourage you to carefully examine the cylinder bores, I have seen similar symptoms arise from a cracked cylinder wall.

 

[FuzzyDunlop]

Welp. Heads off. Results? Inconclusive. I cant find anything obvious with the headgasket.

I did find a rippled cam seal though. Which may explain the leak on one side.

I Still suspect head lift. I dont have a precision edge to check with, but the machine shop i am taking my head to will. They'll give it a good look over and let me know whatsup.

Bores have minor scoring, which was to be expected, but not cracks that I can see. They actually look better than I expected.

Lots of photos commeth.

Ripped cam seal

 

[FuzzyDunlop]

Pitting on piston head. Is that from Detonation?

 

[FuzzyDunlop]

 

[FuzzyDunlop]

dropped the head and gasket off at the machine shop for them to look at. The machinist said that the #4 cylinder fire ring had signs of blowby which most likely was the cause of my problem.
So it was headgasket failure. But may have been completely unrelated to the oil leaks.

 

[JCH13]

dropped the head and gasket off at the machine shop for them to look at. The machinist said that the #4 cylinder fire ring had signs of blowby which most likely was the cause of my problem.
So it was headgasket failure. But may have been completely unrelated to the oil leaks.

That's good news, all things considered.

The cracked cam oil seal is a nice smoking gun for the oil leak.

At least you know what you have to do to fix both!

 

[jlee]

When you put it back together, make sure the special washer behind the timing belt tensioner goes back on. If you don't put it there, the tensioner won't adjust properly and you may shred your timing belt.

 

[FuzzyDunlop]

When you put it back together, make sure the special washer behind the timing belt tensioner goes back on. If you don't put it there, the tensioner won't adjust properly and you may shred your timing belt.

hmmm. why does that sound vaguely familiar...

hehe.

Yes, I have all the individual parts stored in ziplock bags with all their corresponding bolts and washers.
Now its just a matter of hurry up and wait for parts to arrive.
I have a few little things that need fixing on the car in the meantime, but minor.
This has not been a reliable car. I really hope I dont need to drop the engine again next year, although I have gotten pretty good at it by now.

 

[jlee]

So, if you don't want to break anymore shift forks..

http://franavehicles.com/dogTC.html

:awe:

 

[FuzzyDunlop]

So, if you don't want to break anymore shift forks..

http://franavehicles.com/dogTC.html

:awe:

Ya, I saw those a few months ago. Thats big bucks to spend ontop of a bearing kit. Bearing kit alone is like $1500 to rebuild these trannys. I just took a risk and found a used one.

So I was waiting and waiting for parts and machining for the past couple weeks. While I waited I made some improvements to the engine. Basically just cleaned everything up and put some engine enamel in a few places to make things pretty. I had everything lined up and labelled, ready to be installed as soon as the head came back from the shop.

I had them deck the head flat and also replaced the valve seals, as thats a PITA job if you dont have the proper tools for it.
Cometic MLS Headgasket and ARP Headstuds

Torqued the head down in three steps 22ft/lb, 45ft/lb, and ended on 65ft/lb. That is 5ft/lb MORE than what ARP suggests. Back in the late 90's it was discovered that the 60ft/lb recommendation from ARP is incorrect which can cause premature headgasket failure.
In about 150km Ill remove the valve cover again and re-torque them, simply by backing them out a bit then re-doing the above toque procedure.

All shims were within spec, thankfully, otherwise I would be trying to source replacements which may be a PITA.

Timing belt on, matchmarks lined up. Re-installed tensioner by following a rather specific procedure in the factory service manual. More steps to it than one would think. EDIT: Thats an adjustable cam gear on the exhaust side, as some tuners have found that most 3SGTE builds benefit greatly from a 4degree retard on the exhaust side.

Manifolds back on with new gaskets. Cam cover on with new seals. Shined up and polished.

Just need to pop the tranny, starter, clutch slave cylinder, and mounts back on, then its ready to go back in.

 

[JCH13]

:awe:

Looks great!

 

[FuzzyDunlop]

I have the engine back in the car...

...and was just about to come and post how awesome its running, and how great this clutch feels now that its broke in.

THEN... I heard a loud POP! and I found that I have twisted the frame of my car.
Yup. The good news is JCH13's front engine mount held up wonderfully. The bad news is that it literally ripped the frame infornt of the engine. Split it right open.

Looks like I have a new winter project.

 

[jlee]

D:


whoa.

 

[exdeath]

https://www.youtube.com/watch?v=3JaPWAls6qs