I posted this question on the LS1/LS6 Internal Forum a few days ago, but there has not been much interest. Since the topic is also applicable to the LS2/LS7 series and it is kind of a theoretical question, I decided to move the question over here.

I'm planning to build a 408 Iron Block for my truck (already have the block and some parts). From time to time, I read about strokers and oil consumption. I've done a search here and at performancetrucks.net and there are a few comments on this issue. Some folks say strokers are inherently prone to consume oil and others say theirs works fine. The stock LS1 series in general seems prone to burn some oil when run hard a lot. If I tow my trailer a couple thousand miles, I'll need to add a quart in my LQ4 as it is. Also, when doing a lot of tuning for power enrichment at high MAP's I'll use a quart in a thousand miles.

Here are my questions.

1. Do you think that strokers are really prone to consume more oil than an engine with the stock 3.662" stroke?

2. Do you think that the consumption issues relate to the way the engine is prepared or component selection (honing, low tension rings, short compression height pistons).

3. Do you think that high consumption is related to the way the engine is broken in?

4. Do you think that high consumption is related to the way that stroker engines are driven (***** to the wall a lot of the time)?

5. Do you think that the whole thing is blown out of proportion?

6. What do you think?

Thanks in advance,

Steve

 

I posted this question on the LS1/LS6 Internal Forum a few days ago, but there has not been much interest. Since the topic is also applicable to the LS2/LS7 series and it is kind of a theoretical question, I decided to move the question over here.

I'm planning to build a 408 Iron Block for my truck (already have the block and some parts). From time to time, I read about strokers and oil consumption. I've done a search here and at performancetrucks.net and there are a few comments on this issue. Some folks say strokers are inherently prone to consume oil and others say theirs works fine. The stock LS1 series in general seems prone to burn some oil when run hard a lot. If I tow my trailer a couple thousand miles, I'll need to add a quart in my LQ4 as it is. Also, when doing a lot of tuning for power enrichment at high MAP's I'll use a quart in a thousand miles.

Here are my questions.

1. Do you think that strokers are really prone to consume more oil than an engine with the stock 3.662" stroke?
Usually yes. This is because unless you use a longer sleeve, the piston will either have to be shorter, which creates rock, or it will have to stick out of the bottom of the sleave, which also will create some rock.

2. Do you think that the consumption issues relate to the way the engine is prepared or component selection (honing, low tension rings, short compression height pistons).
yes, this also has a major part in it

3. Do you think that high consumption is related to the way the engine is broken in?
yes

4. Do you think that high consumption is related to the way that stroker engines are driven (***** to the wall a lot of the time)?
yes

5. Do you think that the whole thing is blown out of proportion?
Well, you have to understand consequences before you purchase. Don't be nieve and read all the stories and go, "well that's someone esle's problem" and then bitch when the same thing happens. Understand that any time an engine is modified, there is always something else that is going to suffer. GM doesn't spend millions of dollars on stuff just because they feel like it. They make things work together as a system to last 200,000 mile

6. What do you think?
If you are going to take the engine apart anyways, do it right and have it sleeved. This way you will be increasing displacement and putting yourself at a lower risk of problems. But don't do a Darton sleeve deal, get a LS2 case from Katech. They have top quality stuff and they stand behind their products.

Thanks in advance,

Steve

 

Mark,
Thanks for your well thought-out response!

Steve

 

[QUOTE=UMIRacing]
Usually yes. This is because unless you use a longer sleeve, the piston will either have to be shorter, which creates rock, or it will have to stick out of the bottom of the sleave, which also will create some rock.

How much stroke can you go and not have ANY rock, therefore no more oil burn than any other engine? Is there any way to go 427 (4.125 BORE X 4.000 STROKE) Or maybe even 441 (4.125 stroke and bore). Warhawk block.

.

 

This all depends on how long of a sleeve you use. I don't remember the exact length change that Katech uses on their sleeve, kind of forgot by now, but I bet Jason could let us know. I do know that they were safe for a 4" stroke for sure.
As for the Warhawk block, I have no clue because I have never seen one.

 

What exactly is the rock that you guys are talking about?? Does the bottom of the piston come out the bottom of the sleeve allowing the piston to put more pressure on onside of itself due the the rod pulling it down and out???

 

I believe that is correct^

 

5.75


Remember Mark, after sleeving an operation must be completed for 4.000" stroke clearance.

 

The piston must be designed for that cylinder length and then the piston no longer knows if it is 6 inches or 6 miles. The shorter the cylinder gets though the more the ring pack must be squeezed and the less skirt is in the cylinder at BDC. The break point of the skirt should be within the cylinder as well so no excessive rocking occurs. You have to look at the stroke and the ring stack you want to use and then see if theres a skirt that can work and fit in there at BDC and still be stable.

 

I understand that the longer the stroke for a given cylinder length, the shorter the compression height piston and therefore the more squeezed together the ring grooves have to be in order for there to be an adequate top land. I would think that the shorter skirt length wouldn't matter as long as at BDC the bottom portion of the wrist pin (at a minimum) did not descend below the bottom of the cylinder.

The crux of my questions is:
1. Are strokers inherently oil burners?
2. Should strokers be avoided for durable daily driver vehicles an reserved more for race type vehicles?

Thanks in advance,

Steve

 

Steve,

Everyone I know goes from small to bigger to bigger with each engine they build and never the other way if that says anything. So does Chevrolet.

 

Thought I would chime in a few responses here...
1.) I think the LSX engines definitely are more prone to burn more oil than many other engine designs. I blame most of it on the oiling system but that is not the thread topic here.
2.) Piston rock is definitely a part of the problem. Not only from the piston being pulled out the bottom of the bore, but also from the fact most strokers utilize a forged piston. The forged piston doesn't fit the bore as tightly as the stock hypereutectic pistons did, allowing some additional rock as well. The problem is worse when piston to wall clearance is opened up for a power adder application. All this can add to some additional oil consumption. I beleive the biggest part is the fact that if you bought a stroker, you like to drive the car hard and you ARE going to drive it hard - why else would you have bought the stroker!! Every engine uses more oil when you beat on it!
The MTI resleeve LS-2 blocks utilize a sleeve that is 6.050 long on the major and minor thrust walls - basically just like the C5R and they definitely require a clearance operation for a 4" stroke! I can tell you oil consumption was less and the skirts looked WAY better when run in a block with the longer sleeve to support the skirt!

To answer your last 2 questions:
1.) Yes, I believe strokers are prone to burn more oil than there "stock" counterparts.
2.) If you are willing to deal with the increased oil consumption and the fact that the engine life is not going to be as long, then I would say there is no need to avoid strokers for durable daily driven vehicles...

 

Daniel,
Thanks for your input. I've ordered a set of Wiseco Custom LS1 Pistons (4.030 Bore/4032 Alloy/-18 CC Dish/1.105" Compression Height/Offset Pins). This way, I will yield my desired 9.5:1 CR with 72 CC combustion chambers and a .041" Fel Pro gasket. That way I can run 87 Octane with ease and without retarding the timing. Brian Nutter at Wiseco and I discussed the alloy and for my normally aspirated daily driver, he recommended 4032 over 2618 Alloy.

Now I'm looking at piston rings and I will use standard tension oil rings, Napier style second compression rings and probably conventional top rings, but I'm trying to stay open minded about gapless (Total Seal) top rings.

Does anyone have opinions about the Gapless Top Rings, good or bad?

Thanks,

Steve

 

Steve,

That's already the setup we use on everything. We don't have any issues at all. People don't really do the gapless tops on the street from what I have seen. I don't know if they could get gummed up over time but we use them on race stuff and they work great.

 

Thanks Erik. I've talked to Billy and Kevin in tech sales support at Total Seal and they say that as long as the cylinder walls have the proper surface finish and the rings are properly installed and gapped, oil consumption will not be a problem with the gapless top ring and the ring pack should have a very durable service life (100,000 miles or so).

Regards,

Steve

 

Exactly what would one consider log engine life? I know the last engine I built I got about 30k miles on it and pulled it to try building something else... and I'll be willing to bet my ls1 get's about that before I swap out for something different, though probably just bigger.

 

I talk to Keith there too but if they are happy and you can afford it I wouldn't be afraid then if they gave you the go ahead. They know their rings! I like the napiers for sure. I have one crazy stroker and it uses no oil at all and it's just scienced out right.

 

Well Let Me Say I Have A 427 (7.0) In My Car And I Have To Put About 2-3 Qrts Every 3 Days No Mater How I Drive It

 

I have a 408 and it uses no oil.

Those of you that lose oil, where does it come from? Are you blowing it through the PCV and back into the intake, or is it blowby from the rings? I was getting a little through the PCV (still a minimal amount... but enough to **** me off that my intake was oily inside, not even enough to show a difference on the dipstick over 3,000 miles), but since deleting the PCV system and installing a breather, i've had no oil consumption issues whatsoever.