You have a built block???

 

Gabe has got a 4.15L BC stroker motor with long tube headers. His build can be found in the NA builds section on my350z.com

IIRC, I think he may have posted something here awhile ago

 

Correct I have a built block like allmotorsedan said.

The first test was performed with practically all the normal boltons and tomei 264 cams and headers.

The second test was performed with everything in my garage minus the SGM long tube headers. I ran the Tomei headers with test pipes.

 

Cosworth does some work porting and honing their valves to specific specs too, not just changing the parts... so that might explain why it works well for their blocks, and maybe not others.

 

Unless you have Cams, headwork, headers more fuel going in your NA cars the coss isn't gonna do much as far as gains go.

 

My new engine is not a typical engine, it was modeled and the headwork and camshaft were custom made for the parts that I have. Passing it through the bench flow and engine dyno, the numbers all checked out. The builder of my block has made Nissan race engines for over 20 years, so it wasn't really just slapping parts on.

 

I don't doubt your build isn't complete, but Cosworth didn't cut any corners at all for that motor when it came to tolerances, and they even knife edged the port dividers and more...

I don't doubt the guy who built your motor either, but remember we're comparing a motor that Cosworth built, with their facilities, tools, machinery, and all...

 

I'm not seeing what you are trying to get at here.

As far as knife edging the port dividers, that's something that is not uncommon to do. Many have it including me.

 

Not the way they did it...

Some of the things they did in that build didn't make much sense, seemed almost unheard of, a bit excessive and impractical, but I guess it must have made a difference. When they knife edged the port dividers, etc... they literally knife edged it to the point where it looks like it'd break... they did a lot of work they normally won't offer customers.

 

I still don't see what you are trying to get at here. Are you saying that the Cosworth Plenum is only good for them?

If you solely want to compare engine dyno numbers (since they haven't ran it on a chasis one), then mine easily outpowers theirs, but that isn't the point of this post or thread. Like I said many times, the manifold is not for my application and I'm simply adding my data point. The bad assumption from my part is that I went off of their dyno comps on their site and assumed that the Cosworth will be superior to the spacer and MREV2 even though they didn't claim it to be. For your benefit, straight from Cosworth's site and the main reason I purchased the plenum to begin with.

http://cosworthusa.com/store/pc/cata...nt%20tests.pdf

Also straight from their site. Comparison of a stock non-revup car with and without the Cosworth Plenum.

http://cosworthusa.com/store/pc/view...2&idproduct=89

This is also from their site, the cylinder heads they used in the test above as well as in the Castrol build. They state max gains of 19% on the intake and 22% on the exhaust side, which is inferior to mine on the intake side but on par for the other. Unfortunately they don't post the lift at which it got those but we can assume it is at max lift of the ZK2 cams.

http://cosworthusa.com/store/pc/view...4&idproduct=68

What's so unique about Cosworth's knife edged port divider, the concept is quite straight forward. Perhaps I'm overlooking something. Obviously porting is an art in itself, but I have no doubt that mine were done properly since the flow numbers are far superior than stock. Also what are the other things that didn't make sense? I've read the multiple articles about it prior to embarking in this project and perhaps i might have overlooked something.

 

Stock intake and tb. No turbos installed yet.
only plenum spacer and z-tube.
full exhaust and z1 headers w/ high flow cats.
cjmotorsports fuel system upgrade S1 kit w/ return line and a 340 pump still set to 51 psi


some other small mods.

I been on Cosworth website and that intake is now listed at $92,500.00… they crazy (worksmotorsports.com).