........an ideal street engine for a truck. There is always the "How much hp?", and "How fast in the quarter?" questions. Lets put together something a little more real world, let's try and figure out a ballpark on how much flywheel hp/tq (leaning towards torque) we could theoretically get out of say a stock head CARBED 351 (if possible figure the worst flowing heads 80 ish up) stock valves and springs, possibly use roller rockers. Yet the carb/intake/cam/exhuast are all open for change. No strokers, no long rod/arm setups. Say stock converter and the average 3.55:1 gears for cam selection purposes. So if we could get together and come up with some specs on the heads (crappy stock) and some cam numbers along with the help of dyno software or some serious mathmatical formulas, lets see what we can achieve. Would like to keep the torque low obviously. Total power doesn't have to exceed 4500rpm as the last time I checked I didn't need to exceed that rpm on the street. I am more or less interested in just how much potential low end torque you could get out of a stock head/internals, with more or less a intake/carb/cam/headers change so I guess the focus is manily on the cam selection as the low end intakes go the majority would probably pick the edelbrock performer or the weiand stealth I guess we could throw professional products. Well let me know what you all think, only thing I am good for is stupid questions so watch out, some real world examples would be good as well. Any and all responses appreciated.

 

No takers?

How about this, what cam in a 351w say aftermarket intake carb and headers did you choose choose? How satisfied? Any hard dyno numbers?

 

I don't have hard numbers but here is my engine. 69 block and heads, home ported the heads and gasket matched. The shortblock is a rebuilt unit with flat tops with valve reliefs so I think I am close to 10.5-1 compression ratio.
Performer 351 intake, Holley 600 vac. sec.
CompCams Extreme 4x4 210-218, cam
Stock exhaust manifolds, have'nt got a set of headers close enough to work yet
PS, PDB, AOD, 3.70 gears.
Cruises at 2K at 70 MPH
I am satisfied with it. I still get about 15 mpg around town but my highway mileage suffered some, it dropped to 13.5 last trip I made but these trucks push alot of air running 80-85 mph
Clint

 

Was the cam you used the one comp cam/retailer selected or one you chose? How is your idle?

 

I talked to them about it and told them my plans and what I had to work with so it was kind of a combined effort. My idle is fairly smooth but I wish it had some lope to it. I was'nt going to sacrifice performance just to get a lopey cam. Mine pulls great from idle up to about 4800rpm's. After 4800 I start to get a little valve float due to stock springs. I will change them when I can
Clint

 

1

 

Sounds good. Did you at all consider the powermax truck crane cam?

 

JW, I like the topic.

When I when thru a list of fully dressed engine weights of Ford engines, it turns out that the 351w and the 460 had the least lbs per cubic inch. I'd start with either of those.

I would want to stroke it but if you're disqualifying that then we leave that out.

It would have to have closed chamber heads. That would leave out the E7TE style heads. Late 70's heads are bogus. GT40p heads are cheap, or the early 70's 351 heads are cheaper.

Zero-deck the block.

Hypereutectic pistons.

If the budget could afford a reduced-base-circle roller cam, then I'd do a roller cam conversion. Otherwise pick a Comp Cams camshaft.

Iron 4bbl intake. Duraspark ignition. 69-70 iron exhaust manifolds. Home ported heads with oversize Ch@vy valves (1.94/1.60). Holley 1850 carb.

I feel like I've forgotten something. Could it be that simple? Maybe.

 

pcmenten
Would this happen to be a combo you have and/or currently running?

anyone
If someone with a desktop dyno could punch these figures in but be more specific with the cam selected that would be great.

 

This is pretty basic, but just had to get my 2 cents in: How about stroking the 351W to 400 cid? Would that be better than the old 400M? I think they are different blocks and the W is better than the M. As for a cam, if it is a truck I would go with a RV type cam, but for say a 90ish T-bird/cougar, I'd want enough of a lopey idle to sound good, but still have good low rpm torque (maybe mutually exclusive?). And then a 4-speed stick would top it all off along with some wide meats and traction enhancing suspension.

 

This is the cam I have, the roller version though. If I was going carb, I would probably choose something bigger, but for the stock speed density, I found no other cam that could produce the same HP/torque levels.

 

JT,

I printed out the Comp Cams specs and didn't like what I saw. Ditto for the Crane Cams.

I know that both have a lot of cams but both seem to favor LSA in the range of 108-110 regardless of whether it's a HE, XE or whatever cam. That would be fine if I had a single-plane intake or a big aftermarket dual-plane intake but for a stock type iron dual plane I'm expecting to see an LSA of no less than 112.

The reduced-base-circle cam was no different.

I'd prefer a cam with about .465 lift, 210^ at .050 and an LSA of 112 or better for a flat-tappet hydraulic lifter camshaft. More lift and more LSA for a roller cam, .480 and 114 or 115^ LSA.

I know that less LSA will make more horsepower...at high RPMs. I want power at low RPMs. Tell me how much torque it makes at 2000 RPM. Serious.

BTW, porting cylinder heads is like putting in a bigger cam. If you port your cylinder heads, you might want to be careful about the cam you put in.

Is it too late to modify my engine combo? I'd like to switch to tri-y headers, 1 1/2" primaries. Exhaust system is 2" or 2 1/4" dual pipes, with crossover.

 

71swissaqua : comp cams are great IMOP, but like metioned above you could have probaly picked a better cam profile, just my 2cents here other than you didnt say what kind of ignition system you have, the biggest thing i see is a 750 double pumper whould seriuosly help wake that motor up!
you could run a 750 vac. sec. if its set up right. but with ported heads, headders and a bigger cam, your chocking that motor with 600 holey. just something to think about. DW

 

pcmenten
so what cam did you like or did you find one?

 

JT,

For the sake of numbers let's use the Crane Cams retrofit roller cam number 449541.

Int/Ex
216/224 degrees at .050
278/286 degrees advertised
112 degrees LSA
.520/.542" lift



Actually this looks pretty good to me. http://www.cranecams.com/master/apps/ford29.htm#1.%20PowerMax