Patman

Dragboat builds race engines for (you guessed it) drag boats, and he asked me to send him the details on the LS1 engine when I was telling him how so many of them had piston slap and oil consumption. He knows his stuff, that's for sure! There is a wealth of information on that message board!

AP-Engineering

Be careful with the above info. Most of it is wrong or mis-stated. The stroke in a LS1 is 3.622 and the bore is 3.898. Also the rods are 6.098, more commonly known to us as a 6.100 rod. The rings in the LS1 are 1.5/1.5/3.0mm not 5/64. The auto industry has not used 5/64 in a little while now. Also the size of the ring does not have anything to do with the oil control problem. Most of our engines today come with the 1.5mm ring pack or smaller. The slipper skirt design has nothing to do with the oil control issue. The tension of the ring is what the problem is and it is mostly the second ring that GM is addressing. I believe GM on their warranty work has been replacing the rings on the LS1's and the second ring is of higher tension. On the stroker note, they will burn more oil than a stock stroke LS1 9 times out of 10. This is due to the increased stroke pulling the piston out of the bottom of the bore which in turn causes te pistons to rock and the rings have a hard time sealing when that happens. Hope this clears up some of that info in the previous post.

Thanks,
Chris Gelineau
Diamond Pistons
877-552-2112 toll free

<small>[ October 10, 2002, 01:30 PM: Message edited by: DIAMOND ]</small>

Pro Stock John

iTrader: (34)

Even better LOL!!!

Patman refer Dragboat to this thread!!! <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Patman

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Pro Stock John:
<strong>Even better LOL!!!

Patman refer Dragboat to this thread!!! <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Will do! <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Jasc

Good info

CAT3

iTrader: (9)

CHRIS (Diamond) Is there any new designs in piston/rings to control oil better in the 383, or use of a different crank to rod ratio? Also, do the 422/416 strokers have this same problem? tm.

BADZ

iTrader: (5)

<img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" /> this is great info John!!!!

SSpeedplay

Yes!!!! Great info...I was the one who started that thread with the Berger SS. Dragboat, Bob, Molakule, Patman, Terry and others on that board are all in a league all their own! <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

00bluehawk#111

iTrader: (1)

great info. i miss my dragboat -9sec 1/4 mi used to make the blown pavement ponders scream like little girls!! <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> nothing like 1600lbs and 850hp of dragboat to get a speed fix. makes my ls1 seem like a slug <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

grb

I don't think you'd see anything like this anywhere else on the internet. <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

WeatherGuy

One other thing doesn't make sense to me -
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"><strong>
The piston speed is not a factor on the LS1 motor. At 6000 RPM it is moving a mere 3662 feet per second.
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I believe he meant 3662 feet per minute. The actual formula is
piston speed ( in feet/minute) = 0.166*stroke*RPM

= 0.166 * 3.62 * 6000 = 3605 feet/minute

For comparison, muzzle velocity of a 220 grain 30-30 bullet is about 3200 feet/second. I don't think I would want my pistons going faster than that <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />

Redline-Motorsports

iTrader: (3)

Add this to the oil consumption topic. I have a friend that is an engineer for GM. We have discussed this issue many times and this is a logical reason behind it.

As we are all aware the head bolts on a LS1 engine attach at the bottom of the cylinder bore. GM did this to reduce bore distortion at the top of the bore which is typically caused by the head bolts pulling on the deck of the block. Remember the most important area to have a undistorted bore is at the top of the bore for the compression cycle. Once they reduced bore distortion they decided to use a "low tension" ring to pick up some HP due to reduction of parasitic loss.In theory it was a great idea, in reality it didn't cut it! That's why the only true fix is a ring replacement with a stronger tension ring. I don't think that the PCV modifications really "fix" the problem but they do help to some degree. Either way you look at it, it sucks!! I am in the process of finishing a 418 stroker to replace my head/cam 346 because it is like a crop duster!!

ABNRNGR (Aka Dean)

iTrader: (1)

put 2mm rings in and higher tension and i believe this will fix most of the problems. The out of round on these bores are .0007, which is almost perfect, some of these bores come out worst and still make into our cars. The thinner rings are letting oil blow buy.

<small>[ October 11, 2002, 12:11 AM: Message edited by: Dean ]</small>

Pro Stock John

iTrader: (34)

From...

http://theoildrop.server101.com/ubb/...c;f=1;t=000583

Repost about the LS1:

Not related to lower end knock of the LS1 but some reasons for oil burning and piston slap

The LS1 uses a 3.66620 stroke and a 3.8796 bore with a 6.100 rod that makes for a very aceptable 1.6841 rod ratio. But it came at a cost. They stacked the piston rings and reduced the tension of the rings over a LT1 by 30 percent. Why the reduction in ring tension? I am clueless.Did they not test these motors prior to putting them in between the fenders of a car?Certainly they did but supect it was a money/time issue. Just my opinion.
When they moved that ring set up 1.5 mm they knew they were going to have some piston rock with the use of the slipper skirt style piston generally known for poor oil control.The piston weighs 434 grams which is pretty light for a street motor,it came at a cost though.
They have also used a thinner ring set than the normal 5/64 used on the small Chevy and others. I cannot find out the actual width of the ring but think it to be probably a 1/16 top and second ring which is usually reserved for race motors. That there and the combinations of the 30 percent less spring tension plus a little piston rock is going to burn some oil.I have found the static compression of these engines but do not know the nominal compression which might help in knowing why they reduced the ring tension

The piston speed is not a factor on the LS1 motor. At 6000 RPM it is moving a mere 3662 feet per second.

The fix? Spread the rings back to normal and use the KB method of running the oil control ring through the piston pin hole with a pin in the piston to stop rotation plus a different skirt for less rock, clearanced for the rod and to get the ring tension back up to the norm and a more streetable width for oil control.A 5/64 ring with proper tension will not flutter at 6500 rpm if all else is correct.
Other ways to fix would to be to use a shorter rod and custom piston except that would decrease the dwell time at or near TDC and effect computer/injector timing,,too much to tackle imo for a warranty fix given emmissions

It is not exactly a "shaker motor". The rod ratio proves that but if rounded off a bit it is 3.700 stroke-3.900 bore which is getting close to being a square 345.69 ci motor as opposed to the 350 Chevy which is 3.480 stroke-4.00 bore and used a 5.700 long rod which is a stroked 327 motor.
They were relying on relative good cylinder head flow to off set this and gearing to offset the affects of that long rod and the power band a rod of that length in a motor of this size is usually operated in. In my opinion they would have been much better off to use a 5.700 Powdered Metal rod and a bit larger bore with a better piston design.

I understand GM has offered a "fix" for this in a new piston and or ring set. Can someone tell me what this consists of? Hopefully it did not include the new style tapered face ring?

These are just some thoughts I have without digging into it all too much as I doubt I will ever own one of these motors so no more digging for info and of course,opinions will as usual, vary

Is this a terrible engine? I don't think so but in my opinion they could have bettered it.)

When I said I am clueless on the ring tension I meant they should have known what would happen imo ,,I understand now the "fix" does not incorporate any type of ring pinning to stop rotation.
Every early small Chevy I have tore down with high miles and burning oil had the rings aligned on 4 or so of the 8 pistons. Something to think about when trying a cleaner to fix a consumption problem

When you see a 383 using oil, much the same is happening and alot of them do use oil.

Very detailed post, where does this Dragboat know this stuff?

AP-Engineering

Cat3 - The only true fix for the stroker and large compression engines is to use longer sleeves in the blocks. With the 4.000" + cranks we are pulling the pistons out of the bore to far. When resleeving the blocks you should make sure that they are using the longest sleeve they can. This will cure the bad oil comsumption problems with the big LS1's. The less rock that your pistons see the better the rings will seal. If you use a low tension ring set and street drive your car you will most likely consume a little oil. A standard tension ring set would be the best for the street.

Dean - The size of the ring has nothing to do with the engine burning oil or not sealing. In all of the race engines we use .043 rings and have no problems with burning oil. The tension of the ring is the major reason you do or don't have oil consumption. Honing of the cylinders is also very important. If your bores aren't round then you will have a hard time trying to seal the bore. The things to remember are get a ring set for the application you are trying to do with the car. Don't buy low tension rings for your daily driver, unless you want to put oil in your engine every so often. Also if resleeving a block try to use the longest liner possible.

Crowley

I'm just wondering. What are the effects of burning oil due to this issue? Over a period of time what could happen?

Thanks,
Crowley

<small>[ October 11, 2002, 08:36 AM: Message edited by: Crowley ]</small>

DG Gordon

This really suck for us that dont or cant rebuild our own engines. I have 16500 miles and screwed up and put a cam and headers in and voided my warrenty. Mine didnt use one drop till right after the cam install. Maybe it was the fact that I was shifting at 6600 now instead of 6000.
Now I cant even trade it in or fix it so I am stuck driving a car that uses a qt. of oil a week.
This was my second new SS and my last LS1.

LS1derfull

THE MOST IMPORTANT FACT TO BE LEARNED HERE IS MOST OF US WITH Ls1 motors have acceptable oil consumption, low tension rings make more power! You would have to put a gun to my head to put pistons and rings in my motor that would surely lose power to fix a usage of 1 quart of oil in 3000 miles! Fact: LS1 has innefective valve cover/PCV system baffling, Fact: LS1 has too shallow and compact oil pan design for good oil control, because of F-body fit limitations. Both of these issues need dealing with but GM still provided us with an excellent engine that i wont second guess on ring package or piston design.
Refining this engine and car is what this whole site is about and i am proud of what they gave me to start with! No problem is too big and i will own LS1 cars proudly for the rest of my life! <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

LS1derfull

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by LS1derfull:
<strong>THE MOST IMPORTANT FACT TO BE LEARNED HERE IS MOST OF US WITH Ls1 motors have acceptable oil consumption, low tension rings make more power! You would have to put a gun to my head to put pistons and rings in my motor that would surely lose power to fix a usage of 1 quart of oil in 3000 miles! Fact: LS1 has innefective valve cover/PCV system baffling, Fact: LS1 has too shallow and compact oil pan design for good oil control, because of F-body fit limitations. Both of these issues need dealing with but GM still provided us with an excellent engine that i wont second guess on ring package or piston design.
Refining this engine and car is what this whole site is about and i am proud of what they gave me to start with! No problem is too big and i will own LS1 cars proudly for the rest of my life! <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif"><img border="0" alt="[Camaro]" title="" src="graemlins/camaro.gif" />