85' Carrera ~ over revved engine

rgdtoo · 01-01-2010, 05:26 AM

Hi, this is Bob the knucklehead who over revved his engine at Thunderhill last spring causing:

This...

That is from the #1 cylinder and this is what I think I know so far. The rest of the spark plugs, cylinders 2-6 are undamaged. I haven't been able to compression test 2-6 yet but I don't think it will be an issue.

I drained clean oil (no metal) from both the case and oil reservoir ; so I'm thinking the oil pump is working and the case is undamaged.
I'm hoping the only damage is to the #1 cylinder, piston, valve(s), rocker arm, and ??? etc...

Is that a reasonable guess?

I just started a new career path mid last year, because of that I need to build a strong engine fix with little $. Boy if that isn't an Oxymoron.

Anyway ~ I should have the engine out tomorrow.

Let the games begin.

Tippy · 01-01-2010, 06:35 AM

Does the motor run at all? If not, I hate to say, you most likely floated the valves and the bent the exhaust valves.

rgdtoo · 01-01-2010, 02:34 PM

Yes it runs, smoke, noise etc., but it does run.

BURN-BROS · 01-01-2010, 02:42 PM

I would be very concerned about the piston,rod, and rod journal of that cylinder.

I would also replace all the rod bolts after I completely disassembed the engine.

You never know, sometimes the rod journal makes it through the carnage with little damage. Good luck.

efhughes3 · efhughes3's Garage

I didn't damage my pistons at all, didn't break any rockers, but bent all of my exhaust valves slightly when I did the same.

As Aaron mentions, the rods being checked and resized and new rod bolts are usually part of the repair list.

Mine ran too, even with the bent valves. I hate to say it; you're going to have to get in pretty deep. If you jabbed a plug like that, I would assume you've got issues in at least some of the other cylinders.

dshepp806 · dshepp806's Garage

keen, keen eye on that piston....

rgdtoo · 01-05-2010, 10:47 PM

Thanks for the input everybody. After the heads up on the pistons//rods/rod bolts and etc... I had a chance to sit down, read a little, think a little and decided I will cut corners to save $ every place possible.

Ok so I'm pretty sure I am done cutting corners now.

That adapter is about as nifty as I get so I had to share it.
Here let me save you the trouble.

Anyway I have come to the obvious conclusion that it would (I would) be foolhardy not to go thru and re-build the entire engine.

And once again, thanks for the input. (I get the feeling i will be saying thank you a lot as time goes bye)

Speaking of

Bye for now...

rgdtoo · 01-05-2010, 10:52 PM

By the way

Smilies

should be mandatory on every post!

rgdtoo · 01-05-2010, 11:10 PM

Sorry, sleep deprivation!

That's my story and I'm sticking to it.

911 tweaks · 01-06-2010, 03:25 AM

happy trails ..."while you are in there"...

efhughes3 · efhughes3's Garage

Yeehaaa!! Another one joins in.....

rgdtoo · 01-06-2010, 08:57 AM

Here from the outside looking in:

Cylinder one on the right side with the nice crack in it.

rgdtoo · 01-06-2010, 09:01 AM

Now from the exhaust side:

Most of the valve, gone.

Tippy · 01-06-2010, 03:01 PM

Ouch!

777joee · 777joee's Garage

Bob,

Sorry for your loss. The crack in the cylinder is a bit hard to take.......OUCH!

This is now a shameless plug for me as I have a VERY nice 1978 3.0L motor that a bit over 15K ago had 16K spent on a total rebuild. If you or anyone else is interested let me know.

BTW I'm in Sacramento. I would take your dead 3.2 in partial trade.

rgdtoo · 01-08-2010, 01:32 AM

Now with the valve covers off and the same #1 cylinder intake side of the rocker:

By Saturday I should be in the case.

911 tweaks · 05:12 AM

wow... sorry to bring up the actual event, but for us all to learn from this, do you know how hi it rev'd and for how long and how many times have you over rev'd and lastly, this is a stk 3.2 engine, right??
Sorry again for this happening but think of the $$ you will save if you do the work yourself...you can now buy upgraded parts!!! :-)
Bob

efhughes3 · efhughes3's Garage

That is one nasty hit. You're going to need to check everything very carefully. I've always thought I caught mine extremely fast, but felt I was lucky to get away with only bent exhaust valves and no other breakage. I still went through each and every piece of motor to make sure.

cstreit · cstreit's Garage

That must have been one hell of an overrev. Sorry for your pain, been there several times myself. Good luck on the rebuild!

rgdtoo · 01-08-2010, 03:55 PM

Yes 3.2... No clue what the rev was other than, right at red line 3rd into 4th with the pedal pinned. The only problem, I went into 2nd instead of 4th. The money shift, more like the dummy shift.

911 tweaks // No worries on the questions, whats done is done.

efhughes3 // Yeah, me too; I thought I caught it fast. Guess not.

This happened just after the blind right hand #9 at Thunderhill Raceway. There was no noise, vibration nothing at first. I actually went another full lap (3 miles, maybe even two laps) at speed before I saw smoke and felt the power loss. At first I wasn't sure what caused it because, (I caught it so fast~lol), of of the delay between shift and ruin. Adding insult to injury I limped it in not wanting to shut down the track. What a Jack-butt maneuver that was.

One thing is for curtain. I am replacing the shift linkage with one of the aftermarket setups some of my friends are using. Don't know the mfg off hand. I do know it is spring loaded so you have to pull it past the spring tension for 2nd gear.

Time to get to work. As soon as I have the case split etc I will be back with pics seeking advice on how to proceed.