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YOUR RESEARCHLong overdue - engine teardown pics of my turbo (non 996)
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Repair yet
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Performed · outcome unconfirmed
OK Cory, I'll stop giving you crap about not having it repaired yet!
Long overdue - engine teardown pics of my turbo (non 996)
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Leading evidence: 'Repair yet' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'little generous' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Clean inside case' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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So true once I forgot to stagger the oil ring and another is I used chrome rings for longevity, but they took about 2 weeks to break in.
Long overdue - engine teardown pics of my turbo (non 996)
Use i swear
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Performed · outcome unconfirmed · Original poster
Once I used, I swear to this, a piece of sheetmetal bent around the retainers of my girlfriends CJ-7 to stop rocker arm ticking and it worked forever.
Long overdue - engine teardown pics of my turbo (non 996)
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little generous
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A 996 GT2 only does like 320 crank hp/ton and that's probably a little generous.
Long overdue - engine teardown pics of my turbo (non 996)
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Long overdue - engine teardown pics of my turbo (non 996)
Run lower compression heads
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Suggestion
BTW I was reminded today that US spec 3.2s ran lower compression heads from the factory (9.5 versus like 10.3 RoW), which you might want to look into before you build up.
Long overdue - engine teardown pics of my turbo (non 996)
Run ton of boost
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Suggestion
But, if you're already limited at the ports then it won't make much of a difference, and maybe you're better off with a heavier piston if you're running a ton of boost already.
Long overdue - engine teardown pics of my turbo (non 996)
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69 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
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So, for those of you who dont know me or what happened, I overrevved my engine bending the exhaust valves racing.
In an interfernce motor (valves can touch the pistons if a timing belt/chain breaks), if you overrev the motor and the valve springs cannot bring the valves back to seat in time, the piston will strike the valves bending them.
I did not know this as I've been around mostly V8's most of my life (which are pretty much interference free unless you have too large of a camshaft). You learn something everyday.
So, I was racing my friends new BMW 335 coupe with mods done (~385hp) at the drag strip and he was pulling me hard out of the hole (he has 0 boost lag while mine makes almost no boost in 1st gear). When he was about 2-3 car links ahead, I was trying to go into 4th gear and about to make my glorious, fly-by pass for the win.
Well, I missed 4th and was trying to get it in when I actually put it into 2nd at about 90-100MPH.
Once I let the clutch out, the car tried to slow down rapidly and completely died. I tried to restart by letting the clutch out in 3rd but heard all the vaves being lightly tapped by the pistons.
All I thought that happened was I broke a timing chain initially. Needless to say, I had a lesson on what could happen in an overrev of an interference motor....
1. I'm not shadetree for nuthin'
2. Engine on stand
3. Flywheel side of motor
4. Bottom side of motor showing massive oil leakage
5. Intake removed
6. Cam covers removed - preparing to remove cam tensioners
7. Valve strikes shown and one head remaining
8. Cams removed and towers removed
9. Showing all pistons where valves struck
10. Topside shot with cams removed and cam towers removed
11. Need I say more?
12. Busted valve guide
13. Jugs removed
14. All pistons removed - what a biatch. Those clips are really hard to get out without damaging the wrist pin bore.
15. Starting to remove the case bolts and nuts
16. Case halves, IMS, oil pump, and crank
17. IMS and oil pump out of case
18. Close up of IMS drive gear; made of aluminum; pretty impressed it has probably 200k miles on it!
19. Close up of bronze distributor gear. Again, amazing with sooooo many miles that it looks unused like the IMS drive gear.
20. Close up of IMS small journal. Really good shape again for the mileage!
21. Case shot and worn IMS bearing
22. Close up of IMS bearing wear. Pelicanites say it is ok, this will show on break-in.
23. Clean inside case for nearly 200k miles!
24. Chipped Nikasil plating where piston skirt resides. Probably blend and go back it.
Finally! Man part of me doesn't envy you and part of me wishes I was there. Love those german motors, a bitch to get apart, but wow do they wear well. Those internals look like they're just getting broken in.
Since you've done all the hard work taking it apart, allow me to help you spend some of your hard earned:
Maybe a little more stroke on a lighter crank while you're there? What are you going to do for pistons? Mahle or go really lightweight? Maybe drop compression a little for that giant turbo of yours? And since you chunked the liner, you know you need to bore over right? (j/k, well, not really, I'd love to see that project and I don't think you'll be able to blend easily up there without screwing with quench or eventually blowing off the new nickel, but who knows, try asking the LN Engineering guys)
Good luck Cory! Keep us posted, can't wait to see the bench dyno once it's built again
Yeah, I hope I can get it back together.......j/k
I lost count!
I will keep everyone updated, I miss driving it soooo much.
It was actually quite relaxing to do and just get away from school and work and do something I love.
Me too, but it sometimes it hurts the pocketbook to work on them if you know what I mean.
I didnt makeup the phrase but I totally realize
how
the phrase came to be...
Wow Tippy, Very Interesting! Though I'm intimidated by those pieces.
I have to comment on your ghetto jack stands....Brilliant! You must be good at Jenga.
nice write up cory, thanks for sharing and keep plugging away, you will get it back together.
mostly I like the cam chain tenstion rollers, much better idea than a strip of "hard plastic" like the 3.4's have. hat one really escapes me why they would have opted to do that.
Oh I will, just a matter of time and more importantly - money!
Of course I will keep sharing, I really dont know the guys from the 911 forums or 911 turbo forums; just too slow over there.
Well, they do infact have plastic ramps. 4 to be exact that are mounted to the cam cover housings. Matter of fact, once the motor overrevved, it broke one of them. No damage done though.
my favs:
"CORY" in the cement - COOL
Car pictures on edge of garage door
rattle can paint samples on garage wall
the wood stove made from a barrel
work boots in chair
jack stands - perfect !
I think these are awsome and give us the feeling like we are right there in the mix with you Cory!!
I didn't see that either!
<Tim whispers so only Cory can hear> Cory, Ed is a hell of a nice guy, but sometimes I think he lives in the Twilight Zone and has a weekend house in La La Land! He could be a little like this ==>
<Tm stops whispering>
OK, I see it now! He hid it in plain sight! DOH!
By your original description of "'CORY' in the cement - COOL" I was thinking his name had been written or printed IN the wet cement, so that is what I was looking for.
looks like it was written in the cement before it dried to me.
<geesh> speaking of being in LA LA land
HEY CORY, did you write your name in wet cement? hahahhaa!
Holy shi'ite you have good eyes!
Yes, that says my name. It is my Dads shop and we laid the concrete down when I was fairly little. We always scratched our names in the concrete before it dries.
Man that looks painful. The picture of the s in the valve is ridiculous. If you are gonna throw it away i'd take it for a paperweight/conversation starter.
Good luck with the rebuild.
Thats what is going to be for me - a paperweight. Beleive or not, I didnt even clean the valve when I took the picture. It was fairly clean.
Thanks for good luck, ill need it.
My kids name is in the patio and several fence posts around the yard... I started adding the date and am always surprised how the years pass so quickly... I love doing that !
<sharp eye Eddie>
<dull brain>
hahhaha
Heck of a DIY you got there. I wish I had your knowledge. I'm only up to mild bolt on's and basic maintainable. There are several guys that are dropping motors and doing their own dissasembly on this forum, I tip my hat to you guys (no pun intended).
wow big project, time for a big bore kit and a set of ported heads. If you need any manuals let me know I think I have a 930 tear down and rebuild book in pdf. Thats the reason I like my push rod motors, ineffiect as hell but a push rod is a great fusable link.................
Honestly, you cant tear these motors down (or build up) without a manual on your first attempt. I just read word for word and had at it. But, sometimes the wording is vague (in the manual) and you have to just go on instinct from prior knowledge of how things work.
Between you and Hans, y'all are going to make me broke!
Thanks for the offer for the manual, I have every 911 manual in pdf on my computer already (thank you internet! hehe).
Regarding pushrod motors, it kills me that I could rebuild an old V8 in hours and know it will take weeks or months for this motor (not to mention 1000's of dollars vs. 100's of dollars). But, it should be worth it if I dont break a ring and the rings seat the first time out.
"But, it should be worth it if I dont break a ring and the rings seat the first time out"
So true once I forgot to stagger the oil ring and another is I used chrome rings for longevity, but they took about 2 weeks to break in. Just get a good hone and good temps at breakin then cross your fingers.
Chrome rings? What was the material of the bores? Tungsten?!?! hehe
And ol' aircraft mechanic told me that on his farm, he would put Comet in the spark plug holes (of his tractors that he rebuilt) and that the abrasiveness of the Comet would seat the rings.
Needless to say, I never have nor never will try and do that. But, it may work!
Yeah, no kidding. I have read the indexing of the cams about 5 times preparing for actually doing the job.
"Chrome rings? What was the material of the bores? Tungsten?!?!"
It was my first car a Chev "corvair" hey don't laugh... it really was a piece of crap I think I pushed it more then I drove it. The rings where called Chrome Moly and not sure of what the jugs where made of. What I did not know at the time was the whole engine only lasted a few weeks when it ran right so kinda defeated the purpose of the chrome rings. Some of are family was made up of farmers and I had and relative come over and tell me that he substituted a coke cans for the main bearings for his tractor. Well I tried it and it worked!!!
as long as you kept the RPM below 50
GOD I love the smell of burnt coke cans in the morning.
Ah, chromemoly rings. Yes, those are very hard on cylinder walls of a cast-iron block and usually wear out the bores fairly quick. But, you gotta have 'em for performance, especially super/turbocharging
Wow, is all I have to say to the coke cans....
Wow Mother I have heard the coke can legend more than once, I can't believe you actually tried it and it worked!
I think modern moly rings are a little better than they used to be (they used to pour pure molybdenum into the face, now they vaporize it and plate it somehow, apparently they don't eat through iron as badly this way!), but I think the nickel/silicon etc in the 911 bores/liners might not like. I actually only remember there being iron, moly, and chrome rings for the old american iron, not actually sure what differentiates a chromoly ring from a moly ring. Is the first ring chrome and the second ring moly? What are the standard 911 rings made of? Do the turbos have anything special (aside from bore diameter)? There's 3 per cylinder in the 911 right?
Anyway, for Cory: since Brad seems to be in agreement on you boring over (glad to see you back posting here btw), check this out:
http://www.lnengineering.com/911.html
3.7L! Cory, That's a nice odd number. Don't ask me where you get a head gasket or sealing. 8.0 compression for turbo applications. Imagine how much boost you could run. Money's overrated. You can't drive money!
- Hans
The good thing is once you do learn how to do this, you'll be able to knock it out much faster in the future. You could be the SATX 911 big bore rebuild king!
Yes, Im an idiot.
There is no such thing as Chrome moly rings, only moly or chrome rings from what I read. Thanks for pointing that out.
But yes, moly rings eat cast iron like a kid eats candy.
It happened to me in my 355 Chevy motor.
I never heard of chrome rings unitl now, I didnt know there was such a thing until I went to Federal-Moguls website.
To Mothers point, moly rings in my motors would takes weeks to seat too. Blowby like crazy!
And then I will be the brokest in SA too.
Once I used, I swear to this, a piece of sheetmetal bent around the retainers of my girlfriends CJ-7 to stop rocker arm ticking and it worked forever.
Ah yes, shadetree at its best.
HTNY.."Wow Mother I have heard the coke can legend more than once, I can't believe you actually tried it and it worked!" Yes it did temporarily, but the cans where of the highest grade metal back then.
Tippy.. the metal retainer would have been a great idea push rods I could never keep quit for long before adjusting again. Do they still balance and blueprint engines now days? Whats your plan on the rebuild?
Oh yes, but since mine doesnt turn up high, I am not balancing.
My plans for the rebuild just consist of replacing all OEM parts. I may port the heads a little on the exhaust side but I have already cut through a head once before. I spent a few hours welding and grinding the port back to original. I sure as hell dont want that happening to my Porsche head.
I hate you.....
427-447 has been enough now!
I spanked a Honda 600RR on the highway the night I bent the valves. Im sure if he would of downshifted more, it would of been better but I did get the kill. I let off at 140 MPHand had him by a car length.
Hahaha I'm glad I'm getting through! In all seriousness, at the weight of a narrow 1987 3.2, I think low-mid 400s at the wheels is monstrous especially with standard final drive. That's probably 400+ hp/ton at the crank. A 996 GT2 only does like 320 crank hp/ton and that's probably a little generous.
It just makes my mouth water thinking about a nice wide open motor though. Personally I would have a hard time not going a little lighter in the piston if it wasn't much more money (I think aftermarket lightweight forged and OEM/Mahle pricing is probably close) and maybe a little more stroke in the crank if it's even possible, only because you know that turbo will love a little more swept. But, if you're already limited at the ports then it won't make much of a difference, and maybe you're better off with a heavier piston if you're running a ton of boost already. With a turbo, you'll see some results with a little port and polish so that's definitely smart thinking. BTW I was reminded today that US spec 3.2s ran lower compression heads from the factory (9.5 versus like 10.3 RoW), which you might want to look into before you build up.
Either way you'll still be trashing 600s above 120mph and probably anyone else without ***** the size of church bells and a drag bar trailing him.
