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351w cams?

O'Rattlecan

Redneck Prognosticator
26,687
797
Belton, MO
Hey, thanks for the suggestion on the adjustable fuel pressure regulator.

I was reading normal pressure was 39.15 psi. Where is the best place to check this 'average' fuel pressure I was reading about? Just for my own sanity, do you have a suggestion on what pressure you'd start at?

Paul, I do appreciate the help and your patience. I must have missed that part earlier. I'm trying to do all the reading and information absorbing I can but I miss some pieces. If I can get away with a perpetual 19 lb injector by upping the pressure, I would be a HAPPY CAMPER. I'm not looking to get 800 horsepower out of this thing, I'd just like to get most of the parts that might *eventually* get me close to about 350 hp.

I'll do an upgraded intake on my round 2 of upgrades with slightly larger throttle body and maf sensor (to match).

Ryan
 
And I'm not tryng to discourage you just expose the realities of the endeavor. If you search around the web for a "fuel injector calculator" you will see that the numbers are all based on a nominal or reference fuel presure of 43.5psi, this is the pressure at the rail with vacuum removed from the regulator. Using these calculators you can see what effect changing the reference pressure has on HP potential.
 

O'Rattlecan

Redneck Prognosticator
26,687
797
Belton, MO
Cool, I calculate about 51 psi if I get about 350hp out of the deal for a final shot, which should still be do-able with my 19lb injectors.

When I try to get it running with the stock intake & throttle body, I calc'ed just over stock, 44-45 psi.

Ryan
 

BIGRED911

Charter Member
O'rattletrap, when you get dun with your build I wanna know what all you've done, I don't have time to check back everytime on your build but one of these days I'm gonna pull the motor and tranny outa my 92 that's got a whopping 90k on it....it will already scream but I wanna lil more.....
 

O'Rattlecan

Redneck Prognosticator
26,687
797
Belton, MO
CompCams got back to me and recommended this cam:

http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=1053&sb=0

It has even less lift than the one you recommended paul, but the duration is the same.

Either way I think I'm going to need new valvetrain components. I would prefer to go with the original one we were talking about. 35-320-8 because it has a little more lift helping the 351 breathe as good as it can. What valve train components would you change? What would you reuse? CompCams sells entire kits for about $800 bucks. Is it worth it?

Ryan
 
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flareside_thunder

Florida Chapter member
7,812
246
If you stay with 19 lb injectors, consider the 97 explorer 5.0 style ones. They have a different style pintle. I got mine for less than 100 and noticed improvement in power, idle quality, rev and fuel economy.
 

flareside_thunder

Florida Chapter member
7,812
246
The pintle (injector tip) is a different, better atomizing design. The explorer injector has a 4 hole pintle instead of one like your truck has.
 
CompCams got back to me and recommended this cam:

http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=1053&sb=0

It has even less lift than the one you recommended paul, but the duration is the same.
No.. it is the EXACT same cam with 2 degrees less LSA. Didn't we go over all this already? I comment on a lot of build threads here and elsewhere so forgive me if I didn't explain this.

I would prefer to go with the original one we were talking about. 35-320-8 because it has a little more lift.
Well see... no it doesn't. Like I said these two cams are nearly identical with the exact same lobe lift(0.320") which produces 0.512" lift at the valve with 1.6 rockers, pull up the cams spec sheet to confirm this for yourself. Either one of these cams could be used with 1.7 rockers but you don't have to use 1.7 rockers, and adding them won't increase airflow through the motor because airflow stops increasing through these Ford heads at about 0.500" lift, so you're just increasing valvatrain stress for zero gains.
So.. given that which cam to use? If you stay with the SD EFI setup I'd strongly suggest the 349, but with mass air you can use the 320 and that cam will make a little more TQ and HP so why not.



What valve train components would you change? What would you reuse? CompCams sells entire kits for about $800 bucks.
How many miles on this motor? I'd definitely suggest using the matching springs, lifters don't need to be changed but if they have a lot of miles on them and you want a reliable build then yes. Pushrods also don't need to be changed but of the tips show wear then why not considering the modest cost. Nothing else needs to change however, the spider assembly and valvespring retainers and locks are not wear items so there is no good reason they would need changing unless something is obviously broken.
 

O'Rattlecan

Redneck Prognosticator
26,687
797
Belton, MO
No.. it is the EXACT same cam with 2 degrees less LSA. Didn't we go over all this already? I comment on a lot of build threads here and elsewhere so forgive me if I didn't explain this.

Well see... no it doesn't. Like I said these two cams are nearly identical with the exact same lobe lift(0.320") which produces 0.512" lift at the valve with 1.6 rockers, pull up the cams spec sheet to confirm this for yourself. Either one of these cams could be used with 1.7 rockers but you don't have to use 1.7 rockers, and adding them won't increase airflow through the motor because airflow stops increasing through these Ford heads at about 0.500" lift, so you're just increasing valvatrain stress for zero gains.
So.. given that which cam to use? If you stay with the SD EFI setup I'd strongly suggest the 349, but with mass air you can use the 320 and that cam will make a little more TQ and HP so why not.



How many miles on this motor? I'd definitely suggest using the matching springs, lifters don't need to be changed but if they have a lot of miles on them and you want a reliable build then yes. Pushrods also don't need to be changed but of the tips show wear then why not considering the modest cost. Nothing else needs to change however, the spider assembly and valvespring retainers and locks are not wear items so there is no good reason they would need changing unless something is obviously broken.

Thanks Paul, I did notice the cams had the same specs and assumed it was the rockers that changed the lift, but like I said, I'm a newbie to understanding the more technical details of the motor. I can see how it works but when it comes to the science & math of it, I'm at the mercy of the best article I can read.

I have all the parts for mass air flow now, so I'm definitely going to make the swap. As for wear on the motor, it has 236,000 miles on it so I would feel better by at least replacing everything that will wear. The motor looked really clean when I tore it down, but miles are miles.

Before I make my order, the only concern I have is the steel retainers. If Comp sends me these dual spring style valve springs, do you think my retainers will still work? It's only 50 bucks so I guess I can just make the splurge just to be safe.

Ryan
 

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