Cam and compression ratio recommendation for 445 in F250 pulling trailer

[winr1]

Will never be over 4500 rpm...... it’s a work pickup 4 speed manual 3.54 gear

Wants it to pull down low

Will have  428 Cj heads and intake

445 kit is not purchased yet so comp. ratio and cam can be tailored to suit the above

For a gentleman on the FE Fanatics Garage Sale facebook forum



Ricky.

[JamesonRacing]

I did that exact build with Blair Patrick. F250 T19 manual trans, 3.54 gears, 265/75R16 tires. 

We built a 445 engine, ported D2TE heads with CJ valves, iron CJ intake, hydraulic roller cam/valvetrain, Holley Sniper EFI.  Cam is a custom spec, 0.520 lift I/E, 212/218 duration at fifty.  Blair can give you more of the details I'm sure.

Engine idles fairly smooth at 750rpm, but pulls like a beast up to 4500.

[winr1]

Many thanks and I will Dewey know, he is gonna try an join here


Ricky.

[Barry_R]

Small cam equals lower compression ratio - they go hand in hand.
Small cam is duration reduced to move torque peak lower in the RPM band - something like 218ish etc.
But to run that cam you need to reduce compression down into the mid/lower 9:1 range.
Its about cylinder pressure management.

[winr1]

Aye, that is what I was worried about advicing Dewey

I told him he should get with you to tailor the cam to the compression ratio

He is reading this post as a guest


Thanks guys


Ricky.

[winr1]

JamesonRacing, do ya know compression ratio ??



Ricky.

[JamesonRacing]

JamesonRacing, do ya know compression ratio ??



Ricky.

We used dish pistons, and the cylinder head chambers are opened up to around 78ccs.  Blair would have the final calculated CR, but it was under 9.5:1. I wanted to be able to run regular 87 fuel if needed, though I have always used 91 alcohol-free fuel.

[winr1]

Thank you :-)



Ricky.

[Dewey]

Thank you for the info everyone this post was for me I just wasn’t a member yet but this is info I was looking for so thankyou

[My427stang]

Welcome to the forum

I have similar advice.  Get the quench tight, hit 9.5:1 by careful measuring, not estimating, and a 270-ish hyd roller intake lobe with .050 in the 216-218 range, standard 110 LSA on 106, and a little more exhaust lobe and headers, you'll be pulling houses down on pump fuel.

If you go less cam, a little less compression, but the 445s work really well, I can't see any reason to go much less.

[HarleyJack17]

Welcome to the forum

I have similar advice.  Get the quench tight, hit 9.5:1 by careful measuring, not estimating, and a 270-ish hyd roller intake lobe with .050 in the 216-218 range, standard 110 LSA on 106, and a little more exhaust lobe and headers, you'll be pulling houses down on pump fuel.

If you go less cam, a little less compression, but the 445s work really well, I can't see any reason to go much less.

☝️☝️

X2 on this. My 445 build had unworked BBM Heads, and RPM intake, a cam close to the above stated. It had strong low end torque but still pulled a peak of 547 ft. lbs. Compression was around 9.3:1 if memory serves.  If you can find it on the other site, I put a graph out there for it...been about a year and half ago. Unfortunately it has not made it into the truck yet but it's getting closer by the day.  Good luck. 

[Dewey]

So the 260. Cam is just too small, would have to drop compression too much

[My427stang]

So the 260. Cam is just too small, would have to drop compression too much

If you are looking at Barry's custom hyd rollers on his site, that 260 cam is apples and oranges compared to the next one up.  That one has small lobes, LSA at 114, but decent lift.  He can comment, but my guess is that is a stock type replacement roller.  Lift is good, but its real mellow with only 35 degrees overlap.  It's saving grace is that it is likely installed at 108 or 110 which allows it to be run at 9.5:1 as well.

Either cam would work, and no doubt that would keep you at a low peak, but to me, that 260 cam is factory EFI kind of mellow, the next one up seems more appropriate even for something turning low RPM. 

[Joey120373]

Very interested in this build, as it is exactly what i want to do as a secondary or spare engine for my 72-F250, C6, 3.73 grears.

While the big BBM block engine is waiting on $$$ to buy the really good parts, i can't seem to kick the itch to build a more budget friendly 445 stroker.

Barry kinda helped push me over the edge by selling me a set of Oh-So-slightly used Mahle pistons.

My  build will likely use  a set of aluminum heads though.

The cam i want is exactly what you are looking for, straight up torque monster from idle to somewhere in the 4500-5000rpm range.
So i will be very interested in what you use and how it works for you. 

[Barry_R]

If you are looking at Barry's custom hyd rollers on his site, that 260 cam is apples and oranges compared to the next one up.  That one has small lobes, LSA at 114, but decent lift.  He can comment, but my guess is that is a stock type replacement roller.  Lift is good, but its real mellow with only 35 degrees overlap.  It's saving grace is that it is likely installed at 108 or 110 which allows it to be run at 9.5:1 as well.

Either cam would work, and no doubt that would keep you at a low peak, but to me, that 260 cam is factory EFI kind of mellow, the next one up seems more appropriate even for something turning low RPM.

That is exactly what that little fella is.  We originally spec'd it out for a '69 Marauder with a near stock 390 - just a big ol' freeway machine.  Every so often the owner calls me up to report on it, I think he has put 35,000 or 40,000 miles on it so far.  He is a lawyer in the U.P. of Michigan and he uses the car as his daily driver during the non-snowy months often going on four or five hour trips to courthouses around the state.