mark kibort

Sounds like we need to go a route that is proven. We have to think about what this engine is going to be put through. Take Scot Grahams cracked head, we beat the snot out of it on the street. 60-100mph runs, etc, and the car runs great. We go to the track, and in 10min, he is puking water into a secondary overflow and filling it up, yet on the street, it wont loose an ounce of water!

Do we really know what the effects of the extreme abuse on a race engine of steel sleeves on the top outside of the cylinder walls? what about dissimilar expansion rates? what if the cylinder walls are supposed expand, and the steel sleeves reduce the expansion and cause wear on the pistons? heat disippation in the hottest area of the cylinder walls, that normaly has pure aluminum, and now wrapped in steel, is primary concern. Lots of unknowns in extreme use.

Since the components are the real value here, and we already have rods to size, it dictates a custom piston. At this point, we cant use alusil, due to needing a custom piston that mahle NA doesnt do. It sounds like the only other choise is Nicasil, for which JE would be the logical alternative due to not needed a coating and being a little lighter too. So, how do we put together an engine that has a better than good chance of staying together in a racing application. I think that is the mission here.

We also need to get close to 400rwhp, and we all know that a 6 liter with GT cams makes near 360rwhp, which wouldnt buy enough performance for the effort.

Thoughts for the best bang for the buck at this juncture?

Thanks everyone for all the support on this one. It is truely an unbelievabel effort.

Mark K

mspiegle

I was curious what the deal with that was... is it because people put all kinds of money into the block to make it a 6L - then don't do anything to the head/intake to get the extra airflow in?

MK - what are you running as far as exhaust goes?

mark kibort

im running the Devek Level II headers.
ive been told by some that the intake is pretty darn effective. extrude honing doesnt do very much. however big valves and porting provides about 20hp on a 6.5 liter. cams are pretty important,but i cant believe the 1mm more lift is worth more than 10-15hp on top of that.

most of the intake system on the holbert car is pretty stock looking and other 6.5 liter engines have produced near 400rwhp. I would think if it is built right, we should be there. 80hp for a 1.5 liter increase in displacement doesnt seem that far out of the question. i got near 45hp with my 4.7 liter to 5 liter conversion plus bigger valve heads and higher compression ,so we are doing higher compression and near 20% increase in displacement . (1.5 liter)
even if it eneded up near 390rwhp would still be worth it.

mk

mspiegle

Hmm... i wonder how many of those e-rams you can hookup.... 1 per cylinder?

mspiegle

*bright idea*

MK-
When you upgrade your motor... why don't you put the old motor into Scott's car?

Fastest928

We developed a coating and coated 8 sets of pistons. Once piston allegedly "failed" and since the customer was incentivized by another vendor while at the original ICOC to be "aggressive", we no longer provide that service and never recoverd our investment in the process.

Coating the block is a good solution for a race engine. This would be my choice. The coating alone is worth about 5% in reduced friction, assuming the correct rign solution is used.

BTW - 7 engines are still running...so piston coating can be done successfully.

hacker-pschorr

Now we want to talk heads? Well, lets just say Todd has no worries moving enough air to feed the 7 liter he building (or the 6.1 he is currently using). Granted these are supercharged engines, I'm sure he would be willing to work with you & head / valve work.

Hell, why not just have him put 968 valves in your heads?

Rick Carter

A lot of the increase in stroker upper RPM power has come from different intake manifold designs e.g. Phil Threshie and Louie Ott.

hacker-pschorr

Todd is already working on a few different designs for the intake.

Rick Carter

BC

I guess I am seeing this discussion and not getting the directions that some people are pointing at.

The block as it stands is being purchased with Alot of great parts, and the parts that are great are the ones that in my mind would dictate a safe and repeatable route for Mark.

That is:

Stroker Crank
Aftermarket rods
Strengthened towers on the block (these rings supported more pressure then many realize in Todd's motor)

This is a GREAT platform for a long-term racing motor. ALL THAT IS NEEDED is custom pistons by arias or JE, which can be dsigned easily and are very light, and to get the block nikasiled, after being bored to the proper dimentions for whatever piston size is determined.

Coating JE pistons is not a proven solution, and Mahl can't even get thier own new coating right anymore. It is a sacrificial coating as we all know, even when it was tin or iron on the old original pistons.

JEs (or any other forged AL/SI piston) in a Nikasil bore is a PROVEN system and it works long term. JEs can be had for 1000-1200, and the plating would be close to 1800 said and done.

Balance everything for another 1000 down to a knat's eyelash, and be done with it. Figure out how to get more air if needed out of the heads.

Run a high compression piston design, and use a cometic head gasket, after getting the block and heads close to a 50 RA surface rating, and its done.

Well, get the S3 cams from Mark's current motor, and maybe 968 valves.


And again, on the rings that sit outside the bores - if that is a huge issue, find another blank block and get it to 104.

BC

Have a look at that page auto picture link. The machining is just a few milimeters.

John Veninger

Here is a nice intake and heads to go with the new motor.
http://www.eaglesledge.com/parts.htm

mspiegle

I don't fully agree with this. I know of at least 1 person who is running a slightly modified intake manifold making PLENTY of power (far beyond 400rwhp).

mark kibort

we are only talking about 2mm on the side of the cylinders to bore to 104mm. however, if 2mm are missing, and it looks like more, that may not be enough to work with. I certainly dont like those rings in there. again, not proven, and could be certainly problematic. (ie dissimilar materials with different expansion rates, etc

we should just get a scorred block for cheap and bore that and remove that variable.

mk