Engine Failure (1.8- 8v)

[Racerwrtr]

On the pace lap yet! At IRP this weekend for the double regional, leaving turn one heading toward turn two when there was a loud bang and the car filled with smoke. I was turning about 3,000 rpm in third. No, honest I was, you can see it from my in car video. You can also see all of the smoke BEFORE you see the oil pressure gauge go to zero.

After watching the field do three more pace laps (and knowing they were cursing me for all of the oil) and the corner crew spreading oil dry (and cursing me for the same reason) I watched a really nice race from the turn three station. When they got my car back to the paddock, we opened the hood and found the distributor just lying next to the engine. Peering down the hole, the oil pump was a mangled mess. Looking to the back side of the engine, the block was ventilated by a hand-sized hole at number four. I can look right down to the bottom of the pan. There is a mangled connecting rod lying down there and (with a mirror) I can see the crankshaft journal (which looks in good shape). What happened? The bottom end was stock (and high miles) The cylinder head was fresh and very good. Taking a spark plug out of number 4 cylinder, the piston was 2/3 the way to the top, no sign of damage, and easily moved downward when pushed by a screwdriver.

What are my options? Aside from an expensive race motor, I mean. Anybody know of a good place for a short block? I have a spare block, I suppose I could build up a new bottom end with the crank and new rods? Pistons? Any thoughts on what happened and what to do next?

All opinions welcome!

Kevin
85 GTi

[joeg]

Kevin--Do you "violently" scrub your tires on a pace lap?

Sounds like oil starvation.

Replace with JY short block.

Good luck.

[Racerwrtr]

I actually did scrub them a bit harder than usual (parking on a gravel paddock), but the engine has a windage tray and and deep sump, so I would have thought it was safe. It was also about 15-20 seconds after tire scrubbing that it happened. Still, it is a thought...

Why a JY and not an RD engine?

Kevin
85 GTi

[John Herman]

More than likely you damaged the rod bearing some other time while racing, and it picked a pace lap to give up the ghost. Just because you had oil pressure, doesn't mean the bearing wasn't spun or otherwise damaged when you started the pace lap.

[Bill Miller]

I'm w/ John on this one. You coulda slogged a piece of crap around and it could have gotten flung up into the bearing. Although, the distributor thing has me confused. I'd need to probably see some pics to make a decent diagnosis.

As far as the replacement, go w/ a stock bottom end, if you are short on $$$$. I've also got an extra set of stock rods that I can let you have cheap. Before I reused the crank or the pistons, I'd get them checked out.

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MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608

[Racerwrtr]

Can someone explain what a JY engine block is? I can't seem to find it among the engine variations listed in Raven's book.

Also, I suppose it would be illegal to use a 16V bottom end (PL block) with my 8V head? I have a good souce for a 16V short block for cheap, alas.

Just for curiosity, could I put a whole 16V motor into my car and make my ITB car into an ITA car? I don't want to do this right now, but long term, is that even an option, or do the rules forbid such silliness?

Kevin
VW GTi

[joeg]

Kevin--"JY" = "junkyard"

Cheers.

[Racerwrtr]

Oh, I get it!

JY="Junk yard" Very funny. And here I was pouring through all of my VW stuff trying to figure out what a JY block was. Good one on me!

Thanks for the clarification. Anyone care to comment on possibly using a 16V block with an 8V head (if that is even possible)? Totally illegal or ?

Kevin
VW GTi

[racer_tim]

Kevin, the blocks are the same. The piston's are different, so you wouldn't be able to use the 16v pistons with an 8v head.

No wait, you CAN do that but wouldn't be IT legal. That's what I did on my LP GP motor. I took off .005" off the pistons to match the deck height of the 8v pistons in order to get to 11.0:1 which is the max on a LP motor.



------------------
Tim Linerud
San Francisco Region SCCA
#95 GP Wabbit (Bent)
http://linerud.myvnc.com/racing/index.html

[Racerwrtr]

Okay, I have found a nice option on a junkyard motor. I will replace oil pump, water pump, timing belt, head bolts, flywheel bots and clutch bolts and reuse my head. Anything I am forgetting? The remaining oil on the blown up motor looks clean and has no signs of metal trash in it at all, so presumably nothing got into the oil cooler, etc. I think it all happened so fast that there was no time before the oil was in a smear across the race track.

Oh, does anyone know, can I pull the engine (this is an A2)out from the top while leaving the transmission in place? If I can do this, can I also leave the halfshafts attached and in place? Any trick to this?

Thanks for your help!

Kevin
VW GTi

[Team Rocket]

Originally posted by Bill Miller:
Although, the distributor thing has me confused. I'd need to probably see some pics to make a decent diagnosis.


The distributor and oil pump disentegrated due to the broken rod breaking the intermediate shaft (for non-VW people the intermediate shaft drives the distributor and oil pump). That's what happened to my engine: the distributor was laying in the engine bay. I don't know why, but that ticked me off the most: I lost my new BSI rebuilt distributor. Dang.

Racerwrtr, I had a similar failure at race speed last fall. The thread is somewhere in the archives, Oct. of last year.

But hey, when the rod pieces hit the radiator it went between 2 tubes. So I got to reuse it. No leaks! http://Forum.ImprovedTouring.com/it/smile.gif

Jim

[racer_tim]

Don't attempt to pull the motor "up". It's a ton easier to remove everything and drop it out the bottom. Keep the tranny installed, and only remove the inside CV joints, and remove it as a unit, then remove them while there are on the ground.

I would suggest replacing the oil cooler, since you wouldn't want the next motor to blow up because there was junk in the cooler. Cheap insurance.



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Tim Linerud
San Francisco Region SCCA
#95 GP Wabbit (Bent)
http://linerud.myvnc.com/racing/index.html

[Racerwrtr]

The Bentley manual says out through the top for an A2. If I pull it out the bottom, do I still need to pull the radiator support and grille and take off the hood?

kevin
VW Gti (A2)

[Bill Miller]

I think it may be easier to pull an A2 from the top, due to the subframe. However, you should leave the tranny attached, and split them once they're out.

Jim,

That makes sense about the intermediate shaft. Hadn't thought about it much.

------------------
MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608

[joeg]

NEW COOLER AND NEW OIL LINES--give that JY honey a chance!

You always drop VW motors out from the bottom.

Cheers.

[Mark LaBarre]

Didn't re-use the stock rod bolts, did you?

[Racerwrtr]

Just for the three people who might be interested: I have the engine out of the car and a new JY (Junkyard for those of us now in the know) back in place.

The original engine seems to have failed with a ductile failure of the rod bolts on the number four connecting rod. Instead of producing a nice noticeable rod knock, the rod appears to have failed in such a way that it destroyed the piston, broke the auxilliary shaft at the oil pump and distributor drive, broken the counterweight on the crankshaft and generally made a big mess. The worst news is my nice baffled oil pan is peppered with small holes and the baffles are a twisted and mangled wreck. Total loss on everything except the water pump, cylinder head, manifold and accessories. Oh well...

Why did this happen? During the previous session, I shifted from fourth to fifth, but fifth didn't quite engage and I zinged the motor before finding fifth and continuing on. My thought is I must have stretched the rod bolts at the point and then it was just a time bomb...

Are rev limiters legal in IT?

Kevin
VW GTi

[Team Rocket]

Originally posted by Racerwrtr:
broken the counterweight on the crankshaft and generally made a big mess.

Total loss on everything except the ... cylinder head, ..
Kevin
VW GTi

Kev
Did the crank counterweight break at the bearing journal? If so your crank may have been what broke. Rare on 1.8 VW's, but not uneard of... especially if the crank was reground.

And a word of caution from someone who had to learn the lesson the hard way after a similar failure: look that head over real good. I had my head pressure tested and magna-fluxed (crack tested) and everything looked great. So I reused the head when I built my next engine. Well I had the whole shebang back together, and as I'm putting water in the radiator the engine starts leaking. Well, the water was pouring out of the #1 spark plug hole http://Forum.ImprovedTouring.com/it/eek.gif (putting in the spark plugs is the absolute last thing I do). Took the head off to find the piston had hit the head and put a .009" local warp in it right near a water jacket hole. Moral: check your head at the failed cylinder for warpage.

As a side note: I put this new engine together with parts I got off of Ebay. Used block, crank, rods, everything... just cleaned them and put them together. Including used, stock diameter pistons. And it's the best engine I've had to date. Go figure.

Jim

[racer14itc]

Originally posted by Racerwrtr:

Why did this happen? During the previous session, I shifted from fourth to fifth, but fifth didn't quite engage and I zinged the motor before finding fifth and continuing on. My thought is I must have stretched the rod bolts at the point and then it was just a time bomb...

Are rev limiters legal in IT?

Kevin
VW GTi

Yes, rev limiters are legal. I use an MSD6AL in my Scirocco just to protect against this exact situation. I know some folks like Dick Shine dislike MSD ignitions, but the stock ignition (Bosch) doesn't have rev limit capabilities (that I'm aware of).

You can fire an MSD with a stock Bosch ignition system, so it's a pretty easy installation.

Good luck with the new motor!

MC


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Mark Coffin
#14 GP BSI Racing/Airborn Coatings/The Shop VW
Scirocco
Zephyr Race Coaching and Consulting
http://pages.prodigy.net/Scirocco14gp

[Racerwrtr]

Good call on the head. You can bet i looked at it VERY carefully, but didn't see any signs on the head or piston that the two ever met. The breakage at the counterweight was actually just around the journal, so I am pretty sure it happened as parts and pieces were flying about inside the engine. The fact that the inch or so thick intermediate shaft could be broken gives evidence of the forces involved inside one of these things.

I have a spare block, crank pistons, etc and will probably build another motor eventually, but the junkyard motor was $150, with good compression values and good idle oil pressure values, sso I figured it would be less than the machine work to get my othet block ready. This is a hobby afterall! I replaced the oil pump, water pump and timing belt and replaced the front and rear seals while I was at it.

For rev limiters, pertronics just came out with a new digital rev limiter with tach connection for around $100 so I may try that. It works with the stock ignition system and I guess I could argue that it is part of the tach if I needed to.

Thanks for your advice!

Kevin
VW GTi

[denny]

I was right behind you in a spec Miata. I couldn't see anything for a couple seconds. On specmiata.com, under the SMug Shots section there's a series of frame captures from my in-car video.

I just wanted to thank you for a great job getting off track so quickly. I was really worried that I was going to hit something solid in all the smoke, but you were already out of the way. And most of the oil was off the racing line.

Denny Mathias SM#88

[Racerwrtr]

"I just wanted to thank you for a great job getting off track so quickly"

Unfortunately, it's a matter of practice makes perfect.... but thanks for noticing!

Kevin
(now back together and running) VW GTi

[Bildon]

>> Kevin, the blocks are the same.

to clarify, 16v blocks are not the same.
Additional oil passages. Squirters, etc.