Depends on which heads and what cc chambers you have?

 

The October 08' issue of CARCRAFT has an article about GEN III/IV strokers, they touch on this very subject, w/pics.

 

Yeah I haven't seen it yet but I heard about it from several other sources. Supposedly it was sponsored by some of the piston companies that didn't know how to get this right and have been making the pistons wrong all this time already but unfortunately that is the way it goes in the magazine world more often than not. Again if you stay with Wiseco, Diamond and Mahle you are alright right now anyway. I mean seriously the LS1 has been out ten years already!

Hopefully now JE and Ross and others can get this right as well. I just stopped worrying about it and only used pistons that actually worked. I probably had 20 sets of pistons from one of these other shops (NOT Wiseco or Diamond and not ones I ordered) that still wouldn't even clear the reluctor and that's a dimension locked in space that doesn't change but they simply weren't clearanced enough. Some had pins too long that simply left no other choice but for the pin and spiroloc area to be clearanced into for reluctor clearance!

Then when I tried to make sure the pistons weren't going to be hoopties with them on the phone the next time and they couldn't understand what I was talking about or just said that they knew how to make pistons. The problem was that I already knew that wasn't true in this case. With other guys there at JE that were more knowledgeable I had some great pistons made but it was just too much of a crap shoot so I went full time to Wiseco and Diamond.

 

www.dominantmotors.com

^They make a cowl hood for gto's.

 

I think that the question to ask would be more how long do your high HP 408 motors last. any motor making that amount of horsepower cannot be expected to last extremely long, but if you look at these motors before they come out of a truck(LQ9,LQ4) as long as they are cared for they do last. Everyone of us buy the motor to make high power and beat on them thats why you hear bad stories.

 

would you ever think of doing the stuff that you think of doing to a 408 with an aluminum block LS1

 

I had the same issue with a set of JE pistons on my old 383 that was built in 99. the machine shop had to do a lot of clearancing for which made the pin boss very thin on one piston and after 50k HARD miles and a few hundered 1/4 passes it was cracked. The motor was torn down for failed springs and the crack was caught before catastrophic failure, but it was definately not a good piston design.

btw, that motor got 27mpg when it made 450rwhp

I went to a 408 with diamond pistons after that.

 

I think the current Wiseco, Diamond, and Mahle stuff all work and on MAC's deal he does have a different skirt on that piston he has which rocks more so he is not crazy! All future big bore stuff from wiseco is coming the shorter style cylinder skirts as now we have the LSX blocks out there to think about whereas before the bigger bore deals were all sleeved with longer cylinders until the LSX came along with big bores but OEM cylinder length.

Brian said they have not have any negative feedback however from the bigger bore LSX stuff anyway with those pistons which still have much tighter taper and skirts as compared to the "average" aftermarket performance piston shape but the new pistons are now all coming with the tighter skirts since we have the shorter bore LSX block and that way it's all the same. I only know of about 5 of the LSX blocks with those other skirts from Wiseco but none had any issues anyway.

Before I always saw crazy stuff with huge taper and way out the bottom of the bore with many other pistons companies and believe it or not they ran for thousands and thousands of miles but they did use oil and had more crankcase pressure. The Wiseco stuff never did any of this which is why we only used them at first and then Diamond which also is aware and designs pistons around the cylinder length.

Keep in mind that at one point ONLY Wiseco and Diamond had stuff that was even in the ballpark and the rest of the piston guys had flat out crazy stuff that smoked like crazy and burned oil on the big stroke stuff. Now all three have nice stuff that works well including Mahle as well.

 

MAC, I thought I had already posted the stuff in the post above this one above us but I never hit "submit" so yes I do not think you are crazy at all. I think that piston you had would work too but as long as you are happy with what you have is all that matters and the Mahles are going to work great as well. You are right that 90 per cent of engine builders are not aware of this in general with any of their engines from my own experiences so far.

 

In the Car Craft article it states that Jud Massengill doesn't like using the 4 inch stroke for a street car, says it's fine for a drag car though. He prefers a 3.75 stroke for the street.

 

Haven't seen the article but the school never built any regular street car engines at all in the time I was there so that would be kind of odd! But again that's why I don't usually put too much stock in what magazines say unfortunately. Now I can say after building many hundreds of them myself that they sure seem to work quite well. 90% of what we do is 4.000 inch stuff and we do about 4+ a week and have for some years. We haven't had any come back so far because of excessive smoking or oil usage so you do the math.

 

Mr. Erik Koenig do you warrenty the motors you build ? If so, do you always claim engine malfunctions to be a nitrous oxide overload/incorrect tune to save your own behind ???

 

Yes I always do that! It works every time! Just blame NOS! Hahahahah right! There's easy tell-tale signs if you have damage caused by tuning or NOS like burned, melted and sand blasted piston tops and plugs covered in aluminum or brown piston bottoms on otherwise new pistons, missing electrodes and ground straps and tuliped valves, butted rings, moly flaked out etc.

Seriously though, NO one warranties NOS stuff unless they are a fool. Reher and Morrison will not warranty a NOS engine and neither will Musi or Fulton or anyone else with a clue even those that are 25,000.00-75,000.00 engines and on up for some of the pro mod stuff.

It's very easy to see damage cause by NOS and especially mistuned NOS. At least 85% of the stuff we are fixing at any one time is NOS related and 95% of that 85% are not engines we did previously but those from other shops. We also at least every month have a high compression hoopty of an engine with extensive detonation damage and the people don't know why it blew up,

They say the shop that built their POS hoopty and tuned it had normal A/F ratios and normal timing and normal plugs and yet the pistons are fried and the things burning oil from stuck ring lands and bad ring lands? GUESS WHAT, you can't run 13 to 1 on the street with pump gas! We see more of that than you might think but we don't build stuff like that.

We used to warranty all our normal NA engines installed by shops for 2 years and 24,000 miles but noticed that no one does that anymore and were advised against it as well by other business but it worked for us. I would still fix anything we did wrong as a matter of principle but burned up pistons and the like are not something that is on that list of course.

The real problem is with the home hobbyist guys and less experienced shops that don't even know how to setup the oil pump pickup or set the height off the bottom of the pan etc. You send a bare shortblock out and then have to spend ten weeks explaining over the phone how to make it all fit when they could of paid us an extra 50.00 to just make it all work while it was here.

I've even made free trips to fix people problems but I always tell them they will pay if I can fix it and don't if I can't and I always can. It's never hard to see what they've done once I am there with the engine. I've had people bitch about no oil pressure and noisy lifters many times and they had no oil in the engine at all. I've seen people put 55cc heads on 408s that gave them 13+ to 1 on pump gas!

If I wasn't there myself they could have lied and might/would have. The no-oil deal happened three times with people right on this board and they know who they are. Luckily all ended up alright since they only idled their car without oil and never drove it at least! The high compression problem of someone putting a way-small head on a bigger engine is harder to diagnose but a cranking compression test usually is a hint.

That's really not even scrating the surface of what I have seen go wrong in the wild wild world of home engine building but it gives you an idea of why most shops won't put a warranty on a bare shortblock anymore.

 

To punctuate a well made point by Erik, earlier in this thread....

The number one and two important items when building a stroker motor are to "hit on the head" the cylinder prep and piston skirt support. Sure, there are many considerations but missing these two will not bode well for power or longevity.

 

Is it more important to use an oil with ZDDP in it for stoker longevity? I'm reading that only a few racing formula oils and Amsoil have much of this compound left in them. Is it correct to assume that along with a correctly designed skirt, you also need extra protection for the skirt so it isnt prone to scuff and wear at the bottom of the stroke?

 

The better oils like Joe Gibbs do have more anti-scuff and wear additives and will show very small improvements but remember too like Brian Nutter said any 2618 aluminum alloy piston will have little lines and scratches at the bottom even with the right prep as that material is just softer and always looks like that due to small debris etc. in the oil. 4032 aluminum alloy won't show almost any marks at all with the right prep work but when those 4032 pistons go they let go in a bad way whereas 2618 is many times more forgiving.

You can almost always see where the bottom of the bore ends on 99.9 percent of 2618 stuff even with stock strokes and again it has no effect on anything and is not really anything to be worried about. With perfectly clean oil (which never happens!) and a magnet or two up top to catch ferrous particles there is a lot less of those scratches. They are mostly from small particles in the oil getting between the bore and the piston like from your retainers and valvesprings wearing etc.

 

Erik,

I want to personally thank you for making so many truly informative posts in this thread. Even though we have never built nearly the number of engines you have here at Thunder, these lessons are things we discovered over the years since we started doing this back in 99 when noone had really done much 4" stoke stuff. We learned the skirt taper issue with JE's the hard way I can assure you. I have spent countless hours with customers in person and on the phone discussing these issues and why we prefered Diamond or Mahle over JE or Ross in these engines. We were actually one of the shops who brought the skirt taper issue to Diamond's attention back in the beginning of their entry into the LS1 market.

Again, thanks for posting, after doing this for all these years, it doesn't take long to figure out who knows their ****. You obviously do. Its always nice to get some verification of my own experience/theories and also to learn something new.

Thanks,
Shane Burgess
Shop/Tech/Customer Service Mgr.
Thunder Racing, Inc.

 

Thanks for the nice words Shane and I have definitely seen a lot of those earlier deals that were haywire. I did two nice JE deals but they were all out customs made with the shorter bore in mind and it took a lot of effort to make it right before they were ordered and after using Wiseco and Diamond they were much more on top of this and made these changes and incorporated it all into their shelf lineup of pistons too.

I had some weird stuff go on with Mahle at the beginning with their ultra thin ring lands and 4032 power adder stuff but they seem to be doing good stuff too now. They are as big as it gets in pistons and very knowledgeable as well. It's taken awhile but at least we have much better pistons to work with now from everyone.

I will also say that it really comes down to the actual people involved at these piston companies and Brian Nutter and Wiseco have really helped me out a ton and they care about this stuff more than some of the other guys I was working with. Also Eric Simone at Diamond has really helped us out a lot with a lot of weird application custom pistons that have worked great as well.

A lot of people take the pistons for granted in all these crazy combos but the pistons are a huge part of any engine and if they aren't right the whole engine is compromised. I used to do engines with parts the customer supplied but with a warning and now I often refuse when I see the bad stuff as I know they will not be happy in the end no matter how much money they save.