jmgak47

iTrader: (3)

Here are the general details of the build for my 00 GMC Single Cab 2wd. Shortblock is the only part bought and choices are flexible if someone has some incite.

HKE 454 LSX (4.185 bore and 4.125 stroke)
11.5:1 or 11.75:1
NW 102mm TB
Fast 102 Intake Manifold
TFS 245cc Heads
1.8 Rockers of some sort.
ARH 1 7/8 Headers with dual 3" cutouts.
Circle D Triple Disk 4400
4L80e Trans
9" 4.30-4.33 gear.

This is a cam that I spec'ed out... this is using the LSL lobes from Comp

255/267 .661/.661 @ 1.8 rr 113 LSA 113 ICL

Tainted

iTrader: (9)

That cam is huuuge lol!!

jmgak47

iTrader: (3)

Not really, considering the application that it is going in.

C5natie

iTrader: (1)

I was looking at the LSX 454 crate motors on Jegs. Those things are sick. I can just imagine the torque youll see with your combo.

zippy

That's a big stick even being a 454. Taking in account the 4400 stall though I would have to assume that you are building this with racing in mind though. With that being the case I think you're in the ball park with that cam. I would recomend going a bit bigger on the cylinder head though and see if you can convince someone to build you a 2" header or use F-Body headers modified to fit. I know the ARH 1 7/8" are the biggest off the shelf header and are a nice piece to boot, but that is a small primary for that big of motor being spun to the 7k range.

jmgak47

iTrader: (3)

A hell of a lot more then a crate motor lol

Yes this is mainly for racing but with the ability to be street driven.

Already looking into the Kooks 1 7/8 stepped 2" with 3 1/2 collector headers. If they will not fit odds are I will go with the TSP 1 7/8 F-Body headers.

Really don't like the design of the ARH's for our trucks.

jmgak47

iTrader: (3)

My other idea was actually larger duration but lower lift...

263/271 .624/.624 @ 1.6 rr 112 LSA 110 ICL

C5natie

iTrader: (1)

I was just comparing. Lol

mark21742

I do see a problem.....if you haven't put the heads on yet is mill some more off of them to get up closer to 12-12.5:1 scr. With a cam this size you will have a very low dynamic compression if you dont.

For example in my 408 I'm running 12.5:1 scr, a 255/271 .624/.624 115lsa cam which drops my dynamic compression down to a very pump gas friendly 8.22:1 dcr.

I'd hate to see you build a great motor that didn't perform the way you thought just because of not having the right compression.

STAR

iTrader: (1)

I would drop it down to a 243/251 113...more average power and better driveabilty.

jmgak47

iTrader: (3)

I know man. Just being a little smart lol By bad.

You raise a very good point. I am new to GM motor and have only cut my teeth on engine knowledge on the new Hemis, there performance world was lacking to say the least... Also the info on the forums was more hearsay then correct info. Teaching myself by doing lots of reading. Knew about this in the back of my head but didn't think on it.

Really am temped to let Chris Frank of Frankenstein Racing Heads take care of the top end and cam. This has me trying to become a expert overnight with these motors and its just not happening lol Just really like understanding everything, instead of relying on others to tell me what to do.

This is going to be a truck build for the track that can be driven on the street. So that would be a baby cam for this build and more suitable for a tighter lower stall speed converter.

jmgak47

iTrader: (3)

Well this motor was designed to have optimal quench with a .041 head gasket. So with -3 cc pistons and 70 cc heads that puts me right at 12.3:1

This cam looks really good with that.

255/267 .661/.661 @ 1.8 rr 112 LSA 110 ICL

This will have me at a dynamic compression of 8.29:1 in the town where I live, which is 400 ft above sea level. And still be 8.37:1 at sea level in case I ever go race in Houston.

Also my exhaust valve will be opening at 67.5 at top dead center which from what I read is right in the butter zone for these larger cube motors.