How much horsepower should I expect?

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So is camquest even more inaccurate? It just told me to expect just about 500 hp...

Since i still have the timing cover off...I do have a 274/280, 564/570 comp mechanical roller tappet cam here too...would that help me at all?
If I do install that cam, would I be safe with 2500 stall still?
 
only as accurate as the info you put in. Meaning you need the flow numbers for those heads.
 
schultec14 said:
Hi, I am almost finished building a small block 408 stroker engine. I was wondering about how much horsepower and tq I should Expect to have out of it.

It has Aluminum Edelbrock performer rpm heads w/2.02's and 1.60's with pocket porting and are port matched to the edelbrock performer rpm air gap intake manifold it has.
I expect it to have around 10-10.25:1 compression
I have a nice 750 edelbrock to go on it
It has block hugger shorty headers w/ 2.5" collectors
Will be flowing through dual 2.5" exhausts with super 40's and an H pipe
It has a comp cams solid roller 268 cam kit, and it's pushing through harland sharp roller rockers.
it has KB IC745 pistons w/ moly rings and Eagle crank and I beam rods. *(how good are these rods??)*

What do you guys think? 400, 450, 500, more?
What difference would I expect if it had a street porting job done vs. just pocket porting?

Thank you,
-ANTHONY
Click to expand...
i say mid 400 sounds respectable.
 
schultec14 said:
So is camquest even more inaccurate? It just told me to expect just about 500 hp...
Click to expand...

I second the notion that I'd like to know what you put in camquest, I gave camquest a try with a 318 build, and, given the same specs, desktop dyno came out more optimistic. (437hp@6500 vs 427hp@6500/402tq@5000 vs 402tq@4500)

What I plugged into desktop dyno:
Bore: 4.030
Stroke: 4.000
Cylinders: 8
Cylinder Heads: Wedge, Fully Ported, Large Valves
Cylinder head flow:
.2 139/110
.3 194/162
.4 240/184
.5 270/187
.55 278/191
Valves: 2.02/1.60
Compression: 10.5
Carburetor: 750 cfm
Manifold: Dual Plane high flow
Exhaust: Small tube headers w/ mufflers
Cam:
268/276 seat-to-seat
218/224 @.50
106 intake centerline/ 110 lsa
.535/.531 lift

Results:
rpm/hp/tq
2000/167/438
3000/262/458
3500/315/473
4000/364/478
4500/405/473
5000/426/448
5500/425/406
6000/399/349
6500/364/294
 
The camquest software worked well for me. I think the key is entering the head flow numbers correctly (not guessing). I entered what I got from Ryan J after he ported my heads + all the other engine specs…for the single plane intakes, use Std Single plane (the others are VERY optimistic). My cam was on file too, the XE286R, 248/254 duration with .576/.582 lift.

Mine said ~530hp (IIRC), which sounds about right if you look at my cars weight, ET and MPH in the ¼.
 
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