LS2 427 with bad rings...
LS2 427 with bad rings... I stated Im running a LS2 based 427 and with talking to different ppl it keeps coming up that my rings may be bad. I understand the compression test and a leak down test. Two different things, but what is the processes in doing these two tests? .Im pretty sure I understand the commpression test, but the leak down test I'm lost For the compression test i understand to unplug coil packs take the fuelpump relay out ect... Just looking for some tips on things todo and NOT todo.
any help comments please
any help comments please
oil consuption. At this time I'm not running a catch can but in the process of getting one. Also the car has been running rich for 2K miles(had a bad tune from the get go) and I've been told I have probly washed down the cylinder walls.
You would pretty much have to be flooding the motor to destroy the rings in 2K miles, sounds like your problem might be the PCV system sucking up oil, its a very common issue. Try disconnecting the PCV hose to the manifold and sticking a breather filter on each valve cover, then drive the car and monitor oil consumption. If your oil consumption decreases significantly or goes away entirely you're found your problem.
How rich are we talking here?? Like stalling/bogging/lots of black smoke rich, or just rich according to the Wideband/O2's??
You would pretty much have to be flooding the motor to destroy the rings in 2K miles, sounds like your problem might be the PCV system sucking up oil, its a very common issue. Try disconnecting the PCV hose to the manifold and sticking a breather filter on each valve cover, then drive the car and monitor oil consumption. If your oil consumption decreases significantly or goes away entirely you're found your problem.
You would pretty much have to be flooding the motor to destroy the rings in 2K miles, sounds like your problem might be the PCV system sucking up oil, its a very common issue. Try disconnecting the PCV hose to the manifold and sticking a breather filter on each valve cover, then drive the car and monitor oil consumption. If your oil consumption decreases significantly or goes away entirely you're found your problem.
At higher Rpm's it cuts out or bogs down as u say. also high revs spits out raw fuel and black smoke. Throws ses codes for running rich in both banks. I've done searches on the LS1 vally being a bad design but I have the LS2 is it as bad or better? Is the catch can a must or is just putting breathers ok?
Found this on another forum...
“ According to Brian Nutter @ Wiseco Piston, LS blocks have varying cylinder lengths ranging from 5.420 in the 6.0 block, 5.455 to 5.475 in the ls1,2,3,92 blocks, LSX at 5.575 and LS7 at 5.900. Most pistons are tapered approximately .050” from bottom to top to accommodate for thermal expansion. It is important that a piston skirt be at full diameter at bdc. The necessary taper must be introduced at a point above this. When the piston is at full diameter at bdc, it will not rock and the bottom of the cylinder will not dig into the skirt-which causes rapid wear. Reducing piston rock also keeps the rings perpendicular to the bore and oil control is much better. It’s also recommended that the bottoms of the cylinders are deburred with a cartridge roll around the circumference. This information applies to a number of different engines and can be used as a guide to prevent rapid failure. Forged Piston manufacturers have different specifications for a piston’s skirt taper depending on the application and it’s important that a customer speaks with them directly to verify proper design. “
FROM WISECO:Wiseco’s LS series pistons are designed to take the power of high boost or nitrous applications, but run reliably and quietly on the street. The 2618 alloy is stronger than 4032, but typically wears quicker. To remedy this, Wiseco uses a permanent skirt coating that lasts the life of the piston. Some forged pistons also have a reputation for being noisy, so Wiseco offsets the pins like the o.e. to reduce this noise on startup. A low friction ring package is designed to maximize ring land thickness and utilizes a special oil ring design that reduces oil consumption. Because the pistons swing very close to the reluctor ring on LS engines, Wiseco was the first to design a forging around a 2.250” wristpin length. To make this possible, it was designed with just enough pin boss spacing to fit the factory connecting rod width. This further increases pin bore bearing area and reduces pin flex as well. Wiseco is the first to offer multifit valve pockets on their pistons. If a guy starts off with a ls1 or 2, and wants to install L92/LS3 heads or even LS7 head later on a bigger bore engine, he can run the same piston. The K464 series piston uses the Wiseco flow-dome technology to hit the needed compression ratio target. Although it’s in the testing stages, the domes are designed to keep air flowing with less turbulence past the valves when the piston is around tdc. Some LS stroker kits are known to have oil consumption. This is mostly a function of piston rock at BDC. Through a lot of research, Wiseco has designed a skirt cam and taper combination that maintains a full diameter at bdc; this keeps oil consumption and skirt wear to a minimum.
“ According to Brian Nutter @ Wiseco Piston, LS blocks have varying cylinder lengths ranging from 5.420 in the 6.0 block, 5.455 to 5.475 in the ls1,2,3,92 blocks, LSX at 5.575 and LS7 at 5.900. Most pistons are tapered approximately .050” from bottom to top to accommodate for thermal expansion. It is important that a piston skirt be at full diameter at bdc. The necessary taper must be introduced at a point above this. When the piston is at full diameter at bdc, it will not rock and the bottom of the cylinder will not dig into the skirt-which causes rapid wear. Reducing piston rock also keeps the rings perpendicular to the bore and oil control is much better. It’s also recommended that the bottoms of the cylinders are deburred with a cartridge roll around the circumference. This information applies to a number of different engines and can be used as a guide to prevent rapid failure. Forged Piston manufacturers have different specifications for a piston’s skirt taper depending on the application and it’s important that a customer speaks with them directly to verify proper design. “
FROM WISECO:Wiseco’s LS series pistons are designed to take the power of high boost or nitrous applications, but run reliably and quietly on the street. The 2618 alloy is stronger than 4032, but typically wears quicker. To remedy this, Wiseco uses a permanent skirt coating that lasts the life of the piston. Some forged pistons also have a reputation for being noisy, so Wiseco offsets the pins like the o.e. to reduce this noise on startup. A low friction ring package is designed to maximize ring land thickness and utilizes a special oil ring design that reduces oil consumption. Because the pistons swing very close to the reluctor ring on LS engines, Wiseco was the first to design a forging around a 2.250” wristpin length. To make this possible, it was designed with just enough pin boss spacing to fit the factory connecting rod width. This further increases pin bore bearing area and reduces pin flex as well. Wiseco is the first to offer multifit valve pockets on their pistons. If a guy starts off with a ls1 or 2, and wants to install L92/LS3 heads or even LS7 head later on a bigger bore engine, he can run the same piston. The K464 series piston uses the Wiseco flow-dome technology to hit the needed compression ratio target. Although it’s in the testing stages, the domes are designed to keep air flowing with less turbulence past the valves when the piston is around tdc. Some LS stroker kits are known to have oil consumption. This is mostly a function of piston rock at BDC. Through a lot of research, Wiseco has designed a skirt cam and taper combination that maintains a full diameter at bdc; this keeps oil consumption and skirt wear to a minimum.
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Is it raw fuel or oil??? My is doing what yours is doing. I think it is the oil rings and the piston design. I am going to the new designed Diamonds or Wiseco pistons and the Total Seal Ring Pack. Piston rock in the bottom of the cylinders is causing a lot of oil consumption issues. When I changed my heads, you could see scuffing on the cylinder walls. My motor doesn't even have 2000 miles on it.
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We did back to back dyno tests with 2 different engines. The first one used standard Pennzoil 30w, the other used Valvoline VR1 30w racing oil. Each engine had 20+ pulls on them. Engine 1 had such excessive ring and cylinder wear that the block had to be bored .020". The second block still had the cross hatch in the sleeves and was sealed up good. It is possible to wash the rings out in a short time but most likely, I would look at the break in oil first. That is why we started including the Valvoline oil with all of our short blocks.
Brian
Brian
We did back to back dyno tests with 2 different engines. The first one used standard Pennzoil 30w, the other used Valvoline VR1 30w racing oil. Each engine had 20+ pulls on them. Engine 1 had such excessive ring and cylinder wear that the block had to be bored .020". The second block still had the cross hatch in the sleeves and was sealed up good. It is possible to wash the rings out in a short time but most likely, I would look at the break in oil first. That is why we started including the Valvoline oil with all of our short blocks.
Brian
Brian
Does fuel shoot out of the tailpipes when you rev the engine in "Park"? Does the exhaust smell like raw gas on your hand if you put your hand by the tailpipe?
Brian,
I have a LS7 based 427 that I got from you guys about 18 months ago. It has about 1900 miles on it at this time. I used and am still using the 10w30 Valvoline NSL oil that you recommended. What do you guys consider normal oil consumption with this type of engine.
Thanks.
I have a LS7 based 427 that I got from you guys about 18 months ago. It has about 1900 miles on it at this time. I used and am still using the 10w30 Valvoline NSL oil that you recommended. What do you guys consider normal oil consumption with this type of engine.
Thanks.
We did back to back dyno tests with 2 different engines. The first one used standard Pennzoil 30w, the other used Valvoline VR1 30w racing oil. Each engine had 20+ pulls on them. Engine 1 had such excessive ring and cylinder wear that the block had to be bored .020". The second block still had the cross hatch in the sleeves and was sealed up good. It is possible to wash the rings out in a short time but most likely, I would look at the break in oil first. That is why we started including the Valvoline oil with all of our short blocks.
Brian
Brian
Wow, 2,000 miles....the rings are most likely done and they will never seat now. You probably need a rebuild now. My brand new 427ci was too rich, I drove it for just 400 miles and I gas washed the rings. I needed to have my brand new engine torn down, rehoned and re-ringed.
Does fuel shoot out of the tailpipes when you rev the engine in "Park"? Does the exhaust smell like raw gas on your hand if you put your hand by the tailpipe?
Does fuel shoot out of the tailpipes when you rev the engine in "Park"? Does the exhaust smell like raw gas on your hand if you put your hand by the tailpipe?
The whole break-in thing is misunderstood. Rings seat in a matter of 10-20 miles of driving. Or a few good dyno pulls. Just like they do at GM with every engine, a few engine dyno pulls and the rings are seated. Out the door they go from there.
Whoever tuned the car is at fault, 100%.
I went through this **** man. I had to send my brand new engine back for a rebuild after 400 miles or so. Once it happens, its all over. I had raw fuel shooting out of my pipes at start-up and when I revved it. Fuel shot 6 feet out of both pipes and smacked the ground still very wet.
Last edited by LS6427; Oct 25, 2008 at 02:32 PM.
Here is what confuses me. I had MTI in Tx build the motor 3 years ago. The car sat for awhile as i was finishing up school. This past summer was able to drive the car alot & thats when I noticed the oil consuption. When they built the motor I also sent my PCM to them for a basic tune(I guess). I later found out(about a month ago) while talking with a guy who used to work at MTI and he told me that what probly happend was when they programmed my PCM they did it assuming i was using stock injector even tho they where sending the motor to me with 30lb ford injectors.??
Here is what confuses me. I had MTI in Tx build the motor 3 years ago. The car sat for awhile as i was finishing up school. This past summer was able to drive the car alot & thats when I noticed the oil consuption. When they built the motor I also sent my PCM to them for a basic tune(I guess). I later found out(about a month ago) while talking with a guy who used to work at MTI and he told me that what probly happend was when they programmed my PCM they did it assuming i was using stock injector even tho they where sending the motor to me with 30lb ford injectors.??
BUT....when the car SAT for awhile, did the engine sit having never been started up? Then you got the PCM from MTI with their tune and then you started it for the first time and drove it around with that tune?
If so, they are 100% at fault. They built it and they tuned it wrong. No way out of it for them unless there's other things we don't know. All engine builders love to say, "if we build it and we tune it, yeah, then we'll warranty it."
If MTI built it and Joe Blow tuner did the PCM tuning....then you'd be screwed with no recourse.
FormerVendor
Joined: Nov 2001
Posts: 3,065
Likes: 6
From: Houston, Tx.
What actual rings are in this engine?
Find out.
Find out.
Here is what confuses me. I had MTI in Tx build the motor 3 years ago. The car sat for awhile as i was finishing up school. This past summer was able to drive the car alot & thats when I noticed the oil consuption. When they built the motor I also sent my PCM to them for a basic tune(I guess). I later found out(about a month ago) while talking with a guy who used to work at MTI and he told me that what probly happend was when they programmed my PCM they did it assuming i was using stock injector even tho they where sending the motor to me with 30lb ford injectors.??