anyone with a desktop dyno? need help

[Jonny-K5]

i'd like to aquire one of these programs,can anyone help me out ? just picked up a rebuilt 350. im wondering what HP it should be making.if not can you run the numbers for me?

350 bored .040 over with 487 heads, isky 262 cam, performer intake w/ quadrajet and around 8.5 to 1 compression. also curious on what numbers it should make with stock ram horn manifolds or 1 3/4 headers.

i was told the 487 heads are good flowing units. they are cast in 1970. are these good stock heads? better than the ones from the 70-80's?

 

[big83chevy4x4]

with manifolds
hp: 250 @ 5500
tq: 259 @ 4500

w/ ram horns
hp: 258 @ 5000
tq: 277 @ 4500

small headers
hp: 296 @ 5000
tq: 310 @ 4500

big headers
hp: 317 @ 5500
tq: 318 @ 4500

these are with 462 heads which are preaty good flowing double humps

the 487 came with the 71-72 LT1 motors

i got this program at autozone for 39.95 /forums/images/graemlins/waytogo.gif

 

[Jonny-K5]

cool, thanks bro! /forums/images/graemlins/thumb.gif

 

[4X4HIGH]

All those numbers mean nothing to you if based on a 462 casting head since those are 64cc heads and the 487 is a 76cc head.

 

[big83chevy4x4]

but the flow is close, right. the cc of the head doesn't matter to this program just the compression

 

[84_Chevy_K10]

Reguardless the numbers are inaccurate unless you have the proper flow numbers. DD 2000 is garbage in, garbage out.

 

[Jonny-K5]

where are the numbers cast on head to tell what they are. ive never seen a 462 or 487 in any sequence on a head. how do you tell?

 

[big83chevy4x4]

they are in the valve cover area, between the 2nd and 3rd spring or the 6th and 7th spring. 462 or 487 are the last 3 numbers

 

[4X4HIGH]

The amount of quench you have plays a big role in determining if it pings or not depending on the compression ratio. The cc's of the head are part of what changes quench area, along with deck height, and compressed head gasket thickness.

 

[alaskanbowtie]

Desk top Dyno is just a figure and can be right, BUT also be off by 30 percent, so keep this in mind! My motor was estimated to make 359 with Desk top but there are alot of variables , i.e. gapless rings, quench, port work etc. Mine made almost 400 h.p. and 438 tq. on the real machine with a little tweeking but I paid 5 bills for this too. So just remember that it's just an idea and usually a little generous!! /forums/images/graemlins/waytogo.gif