Pekka_Perkeles

Well, perhaps not that different. Rather old and well-known technology used here with ported LS3 heads.

Some prefer machining block, but the owner didn't want to remove the whole engine from the car and decided to machine cylinder heads instead of an engine block.

Nice, isn't it?

RMS-MAN

Pekka,
I'm curious what you are doing for head gasket? How are you getting a proper seal for the water jackets? Those rings look really thick. Thx.

MVP'S ZO6

In addition to rms man's question I'm curious as to how much boost and power this setup is making to lift the heads? ARP has a pretty stout stud out for the LS engine that can be torqued down to 100 ftlbs.

BLOWNBLUEZ06

that looks like you came up with your own BHJ O-ring fixture. Nice work!
I have the same questions as above.

Corvette-Chris

Pretty cool, however, with engines being built these days, shops usually machine the block AND a receiver groove in the head.

I'm curious how this is going to work out.

Pekka_Perkeles

Ok, let me fill the blanks.

The short block is several years old, four bolt LS2 stroker, built by A&A. Nothing fancy, usual forged stuff, ARP studs on top and bottom, mild A&A blower cam which I think has something like 218/22x degrees of duration at 0.050. Ported LS3 heads and other supporting mods like headers, fuel system and so on. Ysi and 8 rib setup, boost somewhere around 19 lbs.

With this configuration the car ran 210 mph at standing mile two years ago. Engine output unknown. http://www.youtube.com/watch?v=9WBcPcoKsEA&

There were never any problems at WOT dyno sessions, but standing mile is a lot more harder for the engine and at some point thin deck LS3 heads started to lift. Rather expensive solution would have been to switch to a 6 bolt design. Instead, a $200 copper rings were selected by the owner of the car, based on a recommendation of a local, long time drag racer. To be precise, the recommendation was to machine the block instead of heads, but as it is easily imaginable, that would have taken considerably more time and money. So it was decided to try it differently – just machine the heads.

Head gaskets are not MLS-syle, but the older design with “soft” material around the water passages. The original metal rings in the gasket right next to the combustion chamber were removed by a CNC machine that can be seen in the first message.

I don’t know the details how the correct thickness of copper ring was calculated, but it is easy to guess that it had something to do with the gasket thickness and whatever experience the local drag racer had about copper rings. It is indeed true that rings looks strange, but perhaps the older style head gasket is pretty thick. I don’t know, I only have experience with newer MLS-style gaskets.

If I recall right, from the engine block point of view, the copper rings reside something like 50% on top of a cylinder sleeve and rest of the ring area is then on top of an aluminium block. I'm not sure about this, though.

After the rings were installed I tuned the car. No problems in the dyno during WOT sessions. No water leaks either.

Couple of days later the owner participated once again to a standing mile competition. This time the car reached 204 mph. Unfortunately, one rib from the blower belt hit the vacuum line and thus the meth system was lost during the run and there was up to 4 degrees of knock at fifth gear somewhere around 190 mph. So no new record this time. :-(

All in all, it seems that the copper rings worked as intended. We’ll see what happens in future. Maybe a bit more aggressive cam would be nice – and re-route of vacuum lines.

helga203

What about LS-9 gaskets??? I believe these are the gaskets all the big boost guys are running?????

BLOWNBLUEZ06@RKT Performance

Now I understand. Looking at the fixture with the shavings sitting in the holes did't clue me in to the fact that the head gaskets were under it. Thanks for filling us in Pekka. 210 is gettin' it done!

Pekka_Perkeles

Tried again to destroy the engine.

No luck this time. Total advance around 20..21 degrees, AFR just fine. And 214.1 mph just before the end of the mile.



Need for a 6 bolt heads? Well, maybe not this time.

helga203

Nice what boost did you see, No lifting at all this time????

robert miller

maybe not this time. Man that is moving it.. great job.. Robert

Pekka_Perkeles

No lifting, three separate runs.

2 bar MAP bottoms with YSi easily, so I can't say exactly what is the boost nowadays. Previously it was around 18 I think.

helga203

Nice i know you said around $200 to do the machining headwork is this about right? If you did the work yourself,taking heads off and installing yourself??

0Arun@CCP

On my runs I usually see 255-265 kpa depending on the weather. I have never had any issues with head lifting.

I am wondering why people are having head lifting issues. My compression is not on the low side either, 10.25 for me.

Pekka_Perkeles

No, I didn't do it, I just tuned the car. The owner did the installation and said it's ok to post here the pics. Sorry if I didn't make this clear enough.

I do have my own car and also do all installation and tuning by myself, but that's different story and since I'm back at university after being 15 years elsewhere, my car projects are on hold.

This particular engine had never any head lifting problems in perhaps dozens of dyno runs. I agree that tuning does have a major part of keeping the heads not moving, but at the same time, standing mile is a very tough for the engine. Finally, this was with stock LS3 castings that were already bent and thus structurally not very stiff anymore, so I'd say copper rings do work and aren't that expensive solution if you do most of the work by yourself. And of course having a bit less advance at peak cylinder pressure probably helps as well.

user_name

Definitely a different way to fix the problem. You said the rings were $200, but what would the cost be to the machine shop typically?

5 Liter Eater

21 degrees of advance >18#? Please tell me this is on race gas?

Pekka_Perkeles

You mean here in Finland? :-)

I think I can sense the point here between the lines, or I may be wrong. Please, this is just a very weird way to do things in other side of the world, where we pretty much lack all the information how to build and tune these engines. There's not a single company here that could build fast LS cars for us. Also, the gasoline is different here, dynos here show lot less rwhp and so on. But it's just so fun when everything seems to finally work as intended.

Some of the nice folks in this forum have helped us, which I'm very thankful, as well as some other in U.S, not forgetting A&A, which have a great centrifugal kit for C5 Corvettes.

stevieturbo

Ive never had any head gasket issues like that myself and I'm seeing over 20psi boost, pump fuel + water/meth.

Ive only done 202mph in a mile, but it is with a car nowhere near as aerodynamic as a Vette.
At the 1/2mile and 1km speeds would be quite close. Wind resistance is killing me even there though.

I just have regular MLS gaskets and ARP studs and have made multiple passes like that over 1 mile and 1km and never pushed water. Although I'm down around 9.0:1 CR
Knowing I want to use pump fuel, Ive little interest in pushing the CR higher.

breecher_7

Bret just did a tune for a friend of mine at 20lbs with 20 degrees in it on 93/meth. Runs awesome.

People should not be so affraid of timing, if it takes it, it takes it.