ivai

Well, here's where I'll be posting info/pics. I had originally started with putting a Vitesse Stage II kit in, and decided to change my head gasket and do a valve job due to a low compression number on cylinder #3 (125, compared to 150 on the other cylinders)... When I took off the head, I found serious scoring on #3, and also the piston looked like it was right up against the cylinder wall.Here is the original thread that I was posting on.

Anyways, just yesterday I finished tearing the block the rest of the way down, and BOY do I have a bent rod. For the record, when I turned the crank so #3 should've been at TDC, it wasn't going all the way up.

The pictures will speak for themselves... But that won't stop me from commenting

Cylinder #3.. As you can see, scoring on the right, large gap on the left.


Cylinder head, freshly removed.. All kinds of gunk on #3 compared to the others.


New vs. old


Lots 'o parts..


That's one fugly coolant reservoir!


For cleaning!





Here's the interesting stuff.. These pics really do speak for themselves





And YES, my piston was massaging the block.





Anyways. Right now I'm trying to decide whether I want to do oversize to 100.5 (1500 bucks woth of pistons and rods, plus another few hundred of machine work)... Or maybe go with a 2.7 liter from Chris White ($2850 + whatever it costs for a used set of stock rods.. $100 or so I think)..

I'll keep you guys posted.. Progress will be slow as I'll only be working on this on the weekends for the most part.

-Jeff

Buckaroo Banzi

How did you bend the rod? Timing belt?
I did not see from your pic of #3 cylinder of the valves hitting the piston?
How did the bearings look?

doing a rebuild myself upgrading to Pauter rods and curious as to what happen to you connecting rod?

thanks,
-BB

ivai

Not really sure how I bent the rod.. timing belt's fine, it was replaced about 20k miles ago. I think I had some pre-detonation or something cause it.. Possibly "hydro-lock" as some 'listers have suggested, but I'm not sure how that would work.

When I bought the car (2004), it was stock, and I put a Tial 38mm WG on it, vitesse chips, and a manual boost controller. Mind you, this was my first car that I did any work on. When I took it out for a drive, the boost gauge was pegging around 22psi.. Of course when this would happen I wouldn't keep on the accelerator, but I was sure that either my boost gauge was messed up or my boost controller was messed up... Turned out I had the vacuum lines backwards on the Tial! Well, I found this out by switching them, and then it ran fine after that. This was two years ago! I don't remember hearing any loud banging or booms or whatever, and its run fine since.. But maybe when I went up to 22+ psi for a couple brief moments, the stock injectors couldn't keep up and the mixture went lean.. and I might've gotten detonation.

Anyways, the only pic I took of bearings was the thrust bearing.. its worn down all the way to copper on the front of engine side:



The rod was bent forward, so it was probably pushing the crank backwards, thereby causing excessive wear on this bearing. The other bearings looked fine, except for the #3 rod bearing, which was excessively worn on the front side of it.

-Jeff

OZ951

Ouch... funny how these things go from minor projects to major ones so easily. Bad luck about that particular discovery, interesting that it ran for so long like that if you figure the damage was done so long ago. It will be interesting to hear the out-of-round figures for that cylinder. Good luck with your rebuild.

RKD in OKC

Don't think of it as bad luck...think of it as a push into the performance zone of bigger displacement

chrly924s

I'm pulling the engine on an 86 951 today. Hoping it's 'only' a rod bearing!

Laust Pedersen

Ouch, but it could have been worse. There very likely has been a very high pressure in the combustion chamber (hydrolock or combustion in the compression stroke), in which case the cylinder and rod “compete” to give in. In other words I would look very closely at the cylinder for crack(s) and at the other rods for straightness if they are going to be re-used.

Btw, hydrolock is a silent event (I know from unfortunate experience), the piston is moving very slowly at the very top.

Laust

Darwantae951

Ok, I think I know what hydrolock is, but I would like an explanation just to make sure, please?

-Darwin

ivai

I would appreciate said explanation as well

Laust Pedersen

Wikipedia to the rescue: http://en.wikipedia.org/wiki/Hydrolock

I will add to that “partial hydrolock” for our cars, which is liquid pooling in the downward quench corner of the cylinder. When the piston is near TDC it will “spit” almost all of the liquid out of the quench area resulting in an uneven force and therefore a bending moment on the piston. At high rpm that force can be high enough that the twisting piston can crack the cylinder wall and/or bend the rod.
If the combustion fails during high fuel supply (high rpm high load), gasoline can build up and become the destructive liquid for the case of partial hydrolock (less liquid volume needed to create a disaster).

Due to the sinusoidal motion of the piston it requires very little torque near TDC to do a lot of damage, so despite the amount of damage it can cause, hydrolock is a “silent killer”.

Laust

ivai

Wellll, after a couple weeks of deliberation, I decided to buy a complete used motor. Picked up one with 130k miles from a local 'lister, the engine was off an '87. Had cold compression numbers of 145 145 150 145. I decided to replace all seals, and rebuild it as far as rod bearings, but no further (basically everything except for mains and rings).

I pulled the head and was relieved to see only minor scoring (couldn't catch my fingernail). The bearings looked fine too, but I put in my new ones of course

Oh, and I'm using a lot of parts from my original motor, since they only have 92k miles on them (such as the head, the cam/lifters.. that's basically it).

I only really started pictures after reassembly.. here are some.




Mmmm.. KEP pressure plate covering Fidanza flywheel.. Can't wait to feel that.




Also can't wait to try out this neat turbo



And then I got it in the car.. After some struggling with having the bellhousing on, I decided to take it off.. man it goes in so easy with the bellhousing off.





Anyways, the engine is just sitting on the motor mounts currently, and I have the car jacked up about a foot and a half in the air. Tomorrow I'll be hooking up more stuff.. maybe put in the tranny.. Its coming together slowly but surely.

Its been almost 2 months since I've driven it and I'm going bonkers.. I don't know how you guys can go without your cars for several months at a time!

By the way, I really am excited to try out the fidanza+kep pressure plate.. some people say its too light but I guess we'll see.

Man its late, time for bed (almost 5am here).

aribop

Looking great, Jeff!

420WHP944

Yeah, looking good - best of luck with it.

ibkevin

Jeff - tell me you resealed your balance shaft housings and engine front! and notched your bell housing, and used the oil press reg valve alignment tool, and a new rear main seal, and rebuilt the head, and ...bigger injectors, and 3bar fpr, and ...ebc

This is much easier to do on the stand too...

reno808

which one is this oil press reg valve alignment tool?
is thier a write up on notching your bell housing?