370 truck crank, 429/460 block.
9:1 compression,forged pistons D3VE heads (or equivilant, 95cc I think)
cam 265/270, .480/.500. 1.73:1 rockers
unknown 370 cam timing
headers
dual plane edelbrock performer intake
650 cfm 4v carb (carter/edelbrock)


Thanks for any help

 

its going into an F-600, with the 370 accesories, I dont know if crank snouts are the same or not. if they are, I will use the 68-71 timing chain set, and may make a 460 instead, if they are different, then I will have to use the 370/429 truck timing chain set, and the 370/429 crank.

it will probably not see much action over 4500 RPM

 

I ran the sim a couple of times with different cams. I presumed stock heads and small tube primaries on the headers. Seems like the choice is split between the Edelbrock Performer Plus (p/n 2167) and the Comp Cams 255DEH. I tried the old-standby Lunati 90460 LUN and it made good HP, but at a higher RPM and at the expense of all-important off idle torque. Since your app screams for low-end, I didn't even post the numbers.

Edelbrock Performer Plus 2167
299 HP @4000
421 lb-ft @3000

Comp Cams DE255H
316 HP @4500
416 lb-ft @3000

Looks like either cam would be a good choice. Based on your app I would give the nod to the Edelbrock. It has ever-so-slighly better off-idle torque (by 12 lb-ft or so), and the torque curve is a teensy bit flatter and broader than the Comp unit.

Brad

 

excellent, thank you for your time and effort. I was thinking the edelbrock was pretty close to what I wanted. I'm assuming the stock 370 is around 190 hp, so that should be a nice package, while being daily drivable, and long-lived.

 

Was the 190 rating was SAE net? If so, that would put it somewhere in the 240-250 range at the crank.

Brad

 

my auto shop class has suddenly become interested in this buildup (I'm going to build it at school) and some of my students are curious about several different camshaft specs. (I spoke about how a camshaft is responsible for the "attitude" of an engine)

we looked through the PAW catalog, and they looked at just about every 429/460 cam there is. we boiled it down to a few cams that were close to what you suggested, and we (I) were wondering if you could run these cams too

comp 268H 218-218 /.494 -.494
comp 265H 211-223 / .484 -.510
comp xtrm 210-218 /.505 - .505 (comp xtreme energy 34-235-4)
Ford A460 216-220 /.493 - .502 (ford racing FOR-M-6250-A460)
(on edit)
Ford OEM 193-206 / .432 - .475 (C8SZ-6250-A) 68-700 429/460 stock cam


the rest of the cams looked way too wild, as it is I'm a little worried about cams with .500 lift anyway.

thanks if you can help again, if not thats ok too.

 

I dont know it that is SAE or not, I told the students I'd give them extra credit if they went to the library and found out...

I know they changed HP rating in cars between the 71/72 model years, but I dont know about trucks.

190 was a guess anyway...

 

As a shop teacher, you might want to get the school to purchase Desktop Dyno as a teaching tool. The newer versions (like DynoSim 2003) run upwards of $140 retail, but I bet the software mfg has some type of educational discount. If you have to pull the funds out of your own pocket you might want to investigate picking up an older version like I did (DeskTop Dyno) for around $40-50. It would be a fantastic teaching tool to help your students understand how heads, cams, and other components work together. It would help them get a better start than most - dispelling myths and giving them a factual basis for the rest of their automotive knowledge.

Back to your question. In general, the cams you listed are too "hot" for a work truck - especially something medium duty like an F600 where the truck will probably be used to haul extremely heavy loads at low speeds and may be called on to sit there and idle for hours on end. The torque curves for even these mild street cams are simply not suited for extreme low-end grunt. You should stick with cams specifically designed for low-compression stock heads that optimize off-idle torque.

As an example I ran the sim with the Comp Cams 270H (the closest thing to the 268H that I already have loaded). It makes a little more HP, but significantly less torque than the combo above. Also, the HP it does make is in an RPM range totally unsuitable for a medium duty truck application.

Comp Cams 270H
343 HP @5000
381 lb-ft @4000

At 2000 RPM there is a 70 lb-ft torque deficit vs the Edelbrock cam. That's a 17% decrease in useable torque in the single most important RPM range for your app.

If you want, I can get the specs for the other cam loaded and run them for you, but it will be a day or two. The next few days are going to be pretty busy for me.

Brad

 

Thanks, I do need to get an older version. we are a private school, so funds are tight.