502 F350 engine

I'm not a trans expert.....the guys that are will jump in . I doubt Summit would be the place to get one.

As at least a couple members know, I am trying to gather info for a similarly cammed, similar displacement combo.
It's actually a Mercruiser 4, which as many know is based on the 460.

Couple ques-
- Head wise, I'm thinking a good step bigger- I'm thinking p51 or really, Boss9...and with a single plane converted to EFI... so a little more accurate fueling, possibly a little less cylinder pressure through the bottom RPM's
- Cam I am thinking about is a Lunati, intended for Chrysler, but I've done some investigation and it will borderline work with .874 lifters.
Looking at the Comp book, those look like lobes 5432&5202- 262/270 but only 128 & 132 @ .200. I'm looking at lobes 265/220/138/.555 and 271/226/145/.576. So 10 & 12 degress bigger at .200. (but only 3 & 1 @ adv.) What will that do to the RPM range? Ideally that loses nothing at the bottom but carries the range further up, making some more midrange in the process. Has anyone seen that for real?
With the bigger ports and bigger cam is there anything in the combo that this thread is about, that really becomes "wrong", if you start looking at a few hundred more RPM? In other words, what's the order of factors making it nose over?
- how close to the edge of detonation is this? considering I am willing to feed it straight 92-93 pump, and live at 2100-2600 feet, how much more could I get away with- +0.7 to 1.0 ?

- what diameter headers did you dyno with, btw?

I think the headers were 1-7/8". With 92-93 fuel I'd think another point of compression ratio would be okay.
I'm not a 4 cyl. expert but, being that you will be cutting the displacement of the engine to 1/2 a lot of tq. will disappear. Going bigger on the cyl. head intake port and bigger on the cam will require more gear and rpm.
I'm not sure what you are gonna do with the engine but, with the comp. ratio and hyd. cam I'd assume it's not a racing engine.....if that is the case I think the TFS street/strip or FRPP SCJ heads would be a better choice than the bigger valve/port heads.

No reason to think that the torque will drop off more than the math suggests: 50%
Not that I know it all, for darn sure I don't...
You are thinking of losing the tuning in a dual plane manifold, maybe?
There's that, yeah. That ones a bit of an unknown, or not really- it's like a Torker, really. or just a bit better, the one I have made a little photochop of cutting in half.
Not real sure there's much else, maybe that the parasitic's are going to be a little more than proportionate- the oil pump, the water pump, the mains friction, but it shouldn't be really significant.
I don't think those together are going to knock more than 10-11 lb ft off. I'm not sure about the intake, though. One reason I am going small with the cam.
I'll be dissappointed if I don't see 300lb-ft.

Set on kill, I should be able to make & hold 335 lbs-ft until it would be well over 400 hp- right before it went boom. You are right, that's not what I am looking for, though--- this will be backed up from that quite a bit!

"You are thinking of losing the tuning in a dual plane manifold, maybe?"
..............................................................................................
I'm thinking I do not know much about a 4 cyl.

hah, you are too modest! Too busy Doing while I'm busy reading, just maybe!

Awesome build there Lem!!

If this was to go into a lighter F100 with SCJ heads & a 4.3 or 4.5 stroke....

How reliable do you think it'd be?

For a 3,000 pound towing application.

George.

SCJs , 4.300" , 6.800" rod and keep the comp. moderate......should be fun for a long time.

Bump for Mike P.

I know it's been a while since anyone posted on this thread,but I was just looking back on it and was wondering if the engine is in the truck and how it's doing? Awesome build....

Wow your fast

IDT-572 wrote:Wow your fast

Lol,after we were talking about it, I had to ask

Seems it is the same as selling a new vehicle....no news is good news Someone else inquired about the build a few months ago and I called the owner....he's happy with the combo.

This deal is a real pussy cat.....idle, manners etc. One can ease the clutch out and it'll just walk away w/o touching the gas pedal....when the vacuum secondarys come open the show is on

What kinda gas mileage dose this monster get.