Need advice 67 Sport Fury 383 4 speed rebuild

[tdenkler]

Hi, Never asked for help yet, but I need it now!
I rebuilding a stock 67 Sport Fury 383 4 speed hardtop
Had motor machined .030 over bore, 010 on rods and mains.
I prefer more lowend giddyup than highend.
Since it's a 4 speed, with manual brakes AND steering, not concerned with vacuum or idle.
I want to put a 291 291 .509 cam in with stock 516 heads. The Summit kit I was gonna get has Forged flat tops
which they say gives me @ 8.94 compression. i would like at least 9.5-1, or 10.0-1 compression without breaking pistons or valve heads!
Does anyone know if this combo will work? tried it?
Heads are stock 88cc.
Also, could I or should I change from 1.5 to 1.6 rocker ratio?
I am hoping someone has already plowed this issue and could give me any ideas on what works and what don't work.
Thanks in advance for any advice!

Tom Denkler

tdenkler3853@earthlink.net

 

[commando1]

Hi, Never asked for help yet, but I need it now!
I rebuilding a stock 67 Sport Fury 383 4 speed hardtop
Had motor machined .030 over bore, 010 on rods and mains.
I prefer more lowend giddyup than highend.
Since it's a 4 speed, with manual brakes AND steering, not concerned with vacuum or idle.
I want to put a 291 291 .509 cam in with stock 516 heads. The Summit kit I was gonna get has Forged flat tops

I found out the hard way. Those stock heads and that cam is a big bottleneck. Go under a half inch on the cam or send the heads out for porting. I'd port the heads.


which they say gives me @ 8.94 compression. i would like at least 9.5-1, or 10.0-1 compression without breaking pistons or valve heads!
Does anyone know if this combo will work? tried it?

I'm not trusting their math but that could be right.

Heads are stock 88cc.

Also, could I or should I change from 1.5 to 1.6 rocker ratio?

NO! Especially not with flat tops.

I am hoping someone has already plowed this issue and could give me any ideas on what works and what don't work.
Thanks in advance for any advice!

Tom Denkler

tdenkler3853@earthlink.net

The best thing you can do is put 3.55 gears in a heavy car with a 4 speed. You won't have to drop one nickel into the engine that way.

 

[Newp]

.509 is the wrong direction for low end power.

 

[moper]

The best thing you can do is pay for good performance pistons and blue print the block. The B wedges have taller than factory deck heights and the pistons that are commonly available don't give you much static compression. Add in the head gaskets that are designed for the largest big block bore with an overbore, and heads that are always larger than factory claimed and the poor 383 has a real compression problem. If it's the numbers block, use a shop that can mill the decks and save the ID pad because you have to take a bit off and the numbers will be cut off if you're not careful. On the camshaft - there are much better cams than the .509. A customer's Challenger had the same things as your car - plus power steering. It had the forged TRWs and a .509, with 3.91s and a stick. I replaced the pistons with KB flat tops, decked the block so they were even with it (zero deck height), milled the heads to get a true 9.8:1, and replaced the cam with a Comp XE268. The car is much more driveable, no issues with low end, pulls to 6K hard, and runs well on pump 89. Your C body needs all the low end it can get and that .509 has nothing for torque in a 383, and the low static will make it even worse.

P.S. - wicked cool ride ;)!

 

[has2bmopar]

The best thing you can do is pay for good performance pistons and blue print the block. The B wedges have taller than factory deck heights and the pistons that are commonly available don't give you much static compression. Add in the head gaskets that are designed for the largest big block bore with an overbore, and heads that are always larger than factory claimed and the poor 383 has a real compression problem. If it's the numbers block, use a shop that can mill the decks and save the ID pad because you have to take a bit off and the numbers will be cut off if you're not careful. On the camshaft - there are much better cams than the .509. A customer's Challenger had the same things as your car - plus power steering. It had the forged TRWs and a .509, with 3.91s and a stick. I replaced the pistons with KB flat tops, decked the block so they were even with it (zero deck height), milled the heads to get a true 9.8:1, and replaced the cam with a Comp XE268. The car is much more driveable, no issues with low end, pulls to 6K hard, and runs well on pump 89. Your C body needs all the low end it can get and that .509 has nothing for torque in a 383, and the low static will make it even worse.

P.S. - wicked cool ride ;)!

All good advice, but I built a 440 with a Comp Xtreme Energy cam... 274/ 286 duration, .488/.491 lift and it makes a lot of valvetrain noise. I even rechecked the preload on the lifters, and found out it is just the nature of the more aggressive ramps to have shorter overall duration with a larger cam.

Now that I have done it, I would choose something else. If you want to stay with Mopar, I think the .474 purple shaft may suit you, or possibly look at some Lunati grinds.

If you keep your duration @ .050" between 220-230 degrees it should work well for what you are looking for.

 

[commando1]

All good advice, but I built a 440 with a Comp Xtreme Energy cam... 274/ 286 duration, .488/.491 lift and it makes a lot of valvetrain noise.

That is a huge complaint from most people about Comp Cams. Valve train noise. I know i will never buy another Comp Cam again.
The valve train noise comes from their design of of ramp angles to get a certain idle whupada-whapada-whupada...
Not worth it to me.

 

[moper]

I've never had the noise issue even using the XE294H - but I know plenty who have. It is not "designed in" but it is the combination of the anti-pump-up lifter (Comp's p/n 867-16) and a low preload in a lifter bore with some wear. Crane, Lunati, Ultradyne, and Engle all have a good potential to have the same issue when that type of lifter is used with the fast rate lobes. The problem being a standard lifter can't take the ramp speeds or rev as high. Roller rockers, especially within aluminum valve covers (more so in welded sheetmetal types common now) can amplify and add to the noise.
You don;t have to use anyone's specific cams. Just do some homework and do what has2be suggested - keep the duration at .050 under 230°. IMO - stay away from Mopar Performance.

 

[commando1]

So, recommend me a non-roller hydraulic lifter....

 

[moper]

Consult your camshaft manufacturer.

 

[commando1]

Smartass. WTF do you think Comp Cam is going to recommend for a Comp Camshaft.

 

[moper]

Sorry -
The tech line would ask the same questions (or should): What engine? What rockers? What machining was done to the heads and block? What head gasket is used? What pushrods? When is it noisey? How loud is it? Is it all of them or just some? What oil do you run? What is the indicated oil pressure? What have you tried to fix it? And oh yeah - what camshaft, lifters, and valve springs are in it?
If you didn't know - there are only a few flat tappet lifter manufacturers that sell to all the valvetrain companies. Johnson is probably the best but again a lot will depend on the other parts and your setup of them. The only lifters I know will be noisey - and by design - are Rhodes.

 

[commando1]

Johnson. Thanks. I'll check them out.
aka Scorpion, right?
I'm making a BOM for my current build.

 

[moper]

I don;t know about Scorpion. I'm pretty sure that's not them but they might be a division of the parent company... If you want to buy a set of lifters made by Johnson just order up a set of Iskys or talk to Mike Jones:
Mike Jones
Jones Cam Designs
Denver, NC
jonescams@bellsouth.net
http://www.jonescams.com
(704)489-2449

 

[commando1]

I've got it written down. Thanks.

< Sent from my tablet >

 

[detmatt]

Good thread, thanks gents!

 

[has2bmopar]

I've never had the noise issue even using the XE294H - but I know plenty who have. It is the combination of the anti-pump-up lifter (Comp's p/n 867-16) and a low preload in a lifter bore with some wear. Crane, Lunati, Ultradyne, and Engle all have a good potential to have the same issue when that type of lifter is used with the fast rate lobes. The problem being a standard lifter can't take the ramp speeds or rev as high.

The noise in which I was referring is from the base of the lifter dropping onto the baseline of the lobe and is not related to the internals of a hydraulic lifter, or the bores. A fast ramp cam just needs a roller lifter, and pushing past the limits with a flat tappet is hard on your entire valvetrain. IMO if you want a broader power range spend the money on a roller cam.

I have used the bleed down Crane High Intensity lifters, with a Crower cam and was displeased with them.