I would like some feedback on a little incident which had occured recently occured but first some background(this will be a tad long!):
I purchased this car w/7500K miles from an aquaintance for 45K(DRM C500RSR 2000 Coupe Corvette...the complete package-Ls1 382 stroker w/4.10's in the rear(forged/billet everything on bottom with 4340 Lunati Crank, CNC ported heads w/4 angle SS valve job and titanium retainers 202/160(so it had good parts!) w/upgraded suspension, accusump, pumps, coolers etc. The car, other than a severe detonation problem, ran strong and passed Calif smog due to small Lunati cam. I took it to Fontana Calif Speedway with Speedventures shortly after changing all fluids with a brand called "Pure Power" and ran for about 15 minutes until bolt in crank pulley backed out and spewed oil for a short time. Repaired the problem and was told no damage otherwise. Because of my nature I decided to refresh the entire top end with 205 AFR heads ported to 71CC's, Comp Cams 228/232, 595/588 on 114 LSA, LSX 90mm intake with 36lb bosche injectors, 90mm Nick Williams TB modified MAF and KooKs L/T headers/exh system with 3" X pipe(Magnaflow). I won't give detail as to who did the work as yet but the car produced 470RWHP and 440RWTQ...I set this up for more of a road racing/daily driver application so the power band was excellent through 3200-6600 RPM's.

While the car was apart, some odd things were noted: .024 piston over deck clearence on all pistons heights, 11.9:1 CR with 224/565, 114 cam(can you say ping!) Stretched timing chain(not double roller)...does the piston clearence strike anyone odd? It did my engine builder! I'm new to LS1 technology...more old school here! All else appeared fine.

On to the track: on the first warm up lap at WIllow Springs big track at turn 5 and 6, the DIC lights up with bells and whistles "LOW OIL PSI" I checked my analog and it read maybe 5PSI at 4400RPMs (no loss of power, no oil clouds and temp read 220...heard clitty clacking and idled into the pits. Remind you this brand new set up only 500 miles new...towed it into builder explained my problem and started up...some of same noise but not as intense and oil at 23PSI but no increase with RPM increase...left it there for further diagnosis...2 days later with out tearing it apart, I'm told it's a spun main bearing possibly due to oil pump failure...does the LS1 have a weak oil pump? Builder tells me if they were not ported the plungers had tendency to stick!
Also, possibly cam bearing could have spun and if so block is junk do to fact that you can't put ovesize bearings cause block is tapped out on material...truth? I'm trying to keep calm as the builder appears to be working with me thus far as I just dropped 9K in the !@#$@$!@ thing!

So, I suppose what feedback I'm requesting other than what has already been stated, is the Plus's and Problems associated with the LS1 engines, Stroker motors, suggestions and or similar experiences or Doug Rippie issues...

I'm thinking of replacing the clutch while the motor will eventually be out...has centerforce in it now with no issues at 11K miles...suggestions?

Thanx for letting me vent

 

Wow. Sorry to hear about your issues. But yes, LS1 oil pumps have a history of crapping out at the most inopportune time!

 

i blew my Mustangs 347 stroker and ever since i bought a vette i will never put my money into the engine other than bolt ons

 

 

If you look at the tuners engine packages they sell, typically they will use a different or modified oil pump in the package deal. Hope you can get things to work out!

 

Since your new to LS1s here is some info I can add. And sorry to hear about you motor.

Well a severe detonation problem is a big issue in itself but okay..

Crank Pulley bolts on LS1s are NOT reusable (unless it is upgraded to a ARP). Some even argue how reusable the pulley itself it since these are "press" fit. The Crank Pulley bolt needs to be properly tourqued (which is a ) and replaced once tourqued and removed (it actually stretches).

Well sounds like someone did their homework! Nice setup overall! Only thing I see missing is the ported LS6 oil pump... but we are going to get to that.

The LS1s to have the pistons slightly over the deck clearance normally. .024 is MUCH higher than normal but you said this was a custom built stroker right? Sounds like someone was trying to up the CR. 11.9:1... well you found your detonation problem! Especially in Calif. with 91 octane. Running race gas/torco would help. I agree that cam is too mild for 11.9, but piston valve clearance needs to be checked closely with those pistons. Stock timing chains stretch. Just the way they are. Double rollers or single JWIS chains are common upgrades when doing cam swap.

As others have said... Ported LS6 is a common upgrade. Especially for a track car.

Don't know this one. Maybe someone else?

Well it sounds like the build lacked the few things that many people have found to be the weak links (timing chain, oil pump). Sad because they are cheap parts (around $250 for both) and the labor would be nothing while doing the other work. Sounds like the other parts of the driveline that are issues (left output shaft in the read, stock clutch, (hopefully clutch cylinders)) were upgraded.

The best of the best seems to be the Exedy Dual but it comes with the best of the best price ($1600-1750). Others have had good success with Luk Gold. SPECs are nice pricewise and seem to take the power but a lot of people complain they chatter at soft launch. Do a search and you will find a lot of clutch feedback.


Good luck on your repair! Hope the block is okay.

--Bill

 

I think there is a recommendation (in the owner's manual?), that says to overfill by one quart of oil when racing to prevent oil starvation? Was this done?

There is a historic problen of oil sloshing in hi-g turns and causing the pickup to suck air?

 

wow. nice list of hardware there.

original setup sounded nice too. prolly ran solid until the bolt backed out? ya don't hear many bad things about DRM if any at all. hear he creates pretty solid packages and caters to roadracers.

too bad you couldnt take it back to DRM when the bolt backed out... prolly not easy having another tuner work on a tuner's car.

assuming DRM did the engine a while back (2000?) maybe the oil pump was not a big issue back then and the tuner just felt it was enough to handle the package they put together. that's why I say too bad that you couldnt take it back to DRM cause maybe they would have had the specs on file and maybe have made the upgrade upon taking care of the bolt and any upgrades you wanted to make. also, 93 octane was available back then and tuned that way and when cali went to crap 91 gas, a retune would prolly been needed to account for the gas.

again, tough to a tuner if they didn't know the how it was built and tuned originally. if he knew that DRM didnt port the oil pump, they prolly would have recommended the pump on top of all that hardware they added on instead of making assumptions.

maybe call DRM and see if they have any recommendations to update their package and to handle the additions being made to avoid any further surprises... updating radiator/oil cooler and such.

good luck with the engine.

 

Were you runnning Sunaco 100?
Do you have a PCV setup?
Were you using Felpro or Cometic Gaskets?

.024 out the hole is higher than most builder go on strokers. .010 appears to be the norm.

I would say the clearance appears to be too tight with that cam..

"2 days later with out tearing it apart, I'm told it's a spun main bearing possibly due to oil pump failure...does the LS1 have a weak oil pump?"

How did they figure this one out without tearing it down?
I am positive DRM used a blueprinted pump. It does not mean it cannot fail, but you were not on the track long enough.

"Also, possibly cam bearing could have spun and if so block is junk do to fact that you can't put ovesize bearings cause block is tapped out on material...truth? I'm trying to keep calm as the builder appears to be working with me thus far as I just dropped 9K in the !@#$@$!@ thing!"

This is wrong. DRM has been building engines, racing engines and building full-out race cars from the ground up for as long as I can remember. They are not going to install the wrong parts, IMO.

I would say there was a change(the car ran fine before) between then and now. Somewhere after the changes, is most likely the problem. JMO.

 

If you had any truly "spun" bearings, your engine probably would
not even turn enough to start. You obviously have major bearing
damage - severe wear, out of round condition in the rods, etc. The
noise and vey low pressure are indications of this. If anything was
really spun, you'd break everything. Been there years ago.
The only way to find out how bad things are is to pull it apart.
And you would like to be there at that time to see.

Joel

 

Now I just don't know what to think :eek2: ...perhaps I'm cursed! :judge:

Get this! here's the latest update...builder finally tore engine partially apart... and this is what he found: thrust washer disintegrated, metal parts found in STOCK oil pump elsewhere in system, no blueing anywhere and scortching on crank journal near thrust washer, rod bearing clearances found to be .018 all of them, heads/ cam/ valve train appear ok but builder wants to replace springs in fear that they were heated to compromise heat treating...good news is that all internals appear forged aluminum/steel crank etc...just useless now! :bang: Rippie was the orig builder in 2000(remember only 11000 miles on stroker)...do the rod tolerances seem unusual to anyone? Stock oil pump? what gives! :eek2:

I'm giving the builder till the end of the week to tear it down completely...red flags going up and I'm about out of patience...all feedback neg/pos welcomed :eyes:

 

I'd get hold of DRM and talk to them and see what they actually put in the dang thing and then tell them about the problem your having.

 

DRM...been there done that! Little to no info...too long ago says them!

 

I have a ported LS6 oil pump.....

 

Sorry about your issues! Seriously, I understand. If it's any consolation, I've watch my engine compartment burn due to a brake fluid cap either falling off or never being put on. One hard left on a test drive and brake fluid spilled on my headers and the engine went up in flames. Also had someone put stock 64cc LS6 heads on my 382 without removing some material to increase the head volume. Talk about preignition. With a zero deck I was running 12:1 compression. Oh and a rotating assembly that was 90 grams out of balance. Vibrated so much, it shook the exhaust tips off. Had to disassemble the engine and rebalance the crank. What I'm trying to say is "I feel your pain!" If that's any consolation. You'll figure it out and when it's over you'll know more about the LS! engine than you ever wanted to, but you'll have a very fast car.
What pistons are you using? Dish, Flat top w/valve relief, Dome? Gotta watch the lift on the cam when you go over the deck, especially with dome pistons and/or no valve relief. The guys are right about a ported pump or LS6. Watch your Timing also. 24 degrees is all you need at the top end. If you still have preignition, back it off. Make sure your knock sensors are not turned off. Good luck
Kj

 

day? what day is it again...don't even think I remember what color the car is! :eyes: Well, after much feedback from everyone and my own intuition, I've ordered a LPE shortblock for 2095.00 bal and blueprinted, a upgraded timing chain(don't like the 2x rollers) and a ported LS6 oil pump...this will be a brand new engine assembly with all the bucks I've spent once together..going to let LAPD assemble with new Dual Friction clutch and that's it...I'm done! :bang: I figure with the 4.10's, usable torque should be fine and power with upper end should still be SOTP's...this car is not used for drag but dailey driver and DE's...My 2002 Z car did pretty damed good with 395 at rear with minor bolt on's! This car should still surpass that!

So here is the finale!
My 2700.00 Lunati crank bent, lunati forged rods/pistons undamaged, block cracked, thrust washer disintegrated, LS1 damaged stock oil pump(what gives Rippie!), clearences and tolerances very loose(perhaps due to detonation)...for personal piece of mind, changing rocker arms, top end un damaged. Hopefully the LPE bottom end will last a bit longer :o:

Does anybody know if my cam comp 588/595 228/232 on 114
will be same, more or less loppy idle? CR will still be 10.8:1.

Stay tuned for updates!

 

"...plungers in the oil pump sticking..." what are you talking about? No plungers in an LS1 pump; just the pump lobe inner and outer sprockets and the pressure bypass spring/cup.

I am concluding an oil pump failure at this moment on a customer's car. First time I've seen an LS1 oil pump go bad. A piece of metal debris got into the pump and lodged itself between the outer lobe gear and the inner wall of the pump essentially becoming a shim; pump wont prime or pump. damndest thing I've seen in a while.

.018 rod bearing clearance is HUGE. wont create any oil pressure at that clearance. Needs to be on the order of .003.

Thrust washer?? you mean Thrust Bearing on the #3 main bearing cap position.

Have you purchased another short block yet? If not, get in touch with Shirl Dickey of SDRE (MrEracer here on the forum). He can build you the last motor you'll ever need for a killer price.

also, pin the crank pulley to the crank. Very wise and cheap insurance. No worries of spinning pulley's and bolts off ever again.

good luck.

Robert/ Gen 3 MS