Cam choice

[Scout63]

I know this topic is well hashed out, but I could use some help. I’m having a 440 motor built for my ‘65 Sport Fury four-speed Convertible. I want it to look stock, provide usable low rpm torque, be fairly smooth and have a little bit more rumble than stock. I use the car for cruising around town and errands. The builder has specd a roller cam setup, which is fine with me, but the cam he purchased is a Comp cams Xtreme Energy 230/236 3 bolt hydraulic roller cam. I had asked him to send me cam and head specs for discussion. We spoke yesterday and he said that he can return it and order a different cam. My review of the Comp notes and some YouTube videos have me worried that this is too aggressive for my intended use. Here is the Comp page for the cam:

Xtreme Energy 230/236 Hydraulic Roller Cam (3 Bolt) for Chrysler 383-440

The heads are 440 Source aluminum Stealth heads.

I think I’d like to stay with a Comp cam. There is a 224/230 hydraulic roller cam but it still seems aggressive:

https://www.compcams.com/xtreme-energy-224-230-hydraulic-roller-cam-3-bolt-for-chrysler-383-440.html

Am I better going with a flat tappet cam?
Thanks everyone. Ben

 

[FURYGT]

Ben,

What is the compression going to be? What kind of head work are you having done? What rear gear will you be running?

My initial thoughts are that a flat tappet cam is fine for your application. Does your engine builder understand what your car weighs?

Consider having Dwayne Porter do your heads and help you with a cam selections. There are other cam companies out there that some of the members here prefer.

 

[GOLDMYN]

On the B Body site, there are a few threads talking about "Mr Sixpack" cams. I used one of his on my 71 Charger 440 back 10 years ago and I could burn 275-60-15 at will. doesn't hurt to ask questions. The ph# is Bob K @ 248-477-7776 days or 248-489-4076 evenings

 

[CBODY67]

The advantage of a roller cam is not having to worry about putting high zinc motor oil in the motor. Most are "racer-oriented" and have specs to match. No 440 HP OEM type rollers that I know of.

Lunati has a 440HP-type cam that several in here have in their cars and like. Just a hair more than the stock 440HP cam in lift and duration.

Comp does have a cam, XtremeEnergy 272, I believe, which has a bit more lift and duration than the Chry 440HP cam, kind of like an extension of the old HE268 of old, but with a few more degrees duration and a bit higher lift. KEY thing is "asymmetrical lobe configuration" where the valve opens quickly and closes slow, which puts more area under the lift curve. Which means more power for the duration. I put one of the old HE268s in a 440 block years ago to see how well their advertising was. It was very accurate, the valve opened quickly, held max lift for 10 full degrees of crank rotation, then closed slower. I was impressed! Lunati has some cams like that, too. On a stock, specifically the old, original Purple Shaft Street HEMI 284/284 cam I also checked, max lift was for only 1 degree of crank rotation, by comparison.

A 4-speed can tolerate a slightly wilder cam, but for "cruising" (which can include stopping at red lights and such), having something similar to the stock HP cam can work well and not really need a lot of throttle to get things rolling again. Plus re-start reasonably easy without a lot of drama.

In choosing a camshaft for a car which might be driven a good bit, going to a slightly milder cam rather than one (as my late machine shop operative used to say) "at the bottom of the page" (where the bigger numbers are). To me, a "torque motor that rpms", which means a good dual exhaust system under the car (check other threads about TTI exhaust systems on C-body cars) will allow for plenty of rpms for a good top-end performance. Having a car which runs good without any drama will be much easier to live with in the long run that one which makes a lot of noise and can't scatter guano.

Just some thoughts and observations,
CBODY67

 

[Blusmbl]

If you go with a flat tappet I'd definitely have your engine builder break in the motor before installing it in the car. I've heard of lots of horror stories with modern flat tappets getting wiped prematurely- that alone would probably sway me towards going hydraulic roller. Also agree that depending on your rear gear, that might be a little too much cam if you're looking for near-stock performance at 2000 rpm. Are you going with a stock dual plane intake or something sportier like a Performer RPM?

 

[volksworld]

theoretically there's no reason why you cant accomplish what you want with a flat tappet cam...however with all the horror stories out there about bad lifters and current cams losing lobes i think the roller is a $500 insurance policy by the builder that the thing is going to stay together... there's a you tube out there from the guy at Powell Machine (saw it at the B body forum in general mopar tech) discussing their efforts to try to solve the current flat tappet issues and the fact that they basically gave up

 

[Scout63]

Great feedback all. I'm going to dig into it further and report back. Ben

 

[CBODY67]

Two things . . One is to ensure that the cam and lifters are from the same company. As in buy they together rather than not. That way, should anything happen, they should not be able to wiggle out of things, in that respect.

Two is to have the builder slather the lobes and the back of the timing chain sprocket with moly paste assy lube, then liberally pour some of the GM EOS thick oil additive (used to be in pint cans) over the cam and lifters before the intake is installed. Back of the cam sprocket? Yep, no pressure lube there, nor on the teeth of the sprockets, so using the same pre-lube there can only help.

Then, get the engine in the car as quickly as possible AND kindly request the builder is there and/or oversees the initial cam break-in operation upon initial fire-up. That way, TWO sets of eyes on the situation. Might even set up your phone on a stand to video the whole thing for reference. These things hinge upon whether or not the machine shop has a dyno on which to do the cam break-in operation.

In one respect, a flat tappet can be better as the only typical failure mode is lack of durability in the bottom of the lifter. Yet they can need "better oil" in them for at least 5K miles or so, or longer. Considering the somewhat better availability of such oils in modern times, then the added cost might be the only issue to deal with.

Roller lifters can have issues, too, should their retention mechanism fail and let a lifter rotate in its bore, which kills things quickly and decisively. Then, there are the discussions about rollers with needle bearings on the rollers or bushings instead.

What I dislike about rollers is that FEW of them are not race-oriented with .500" lift and lots of duration, which can compromise lower-rpm livability, usually needing 4-series rear axle gears, too, which also get into the "race" orientation, too. End result can be that, at least initially, getting everything to make a roller cam work as it can will add significant cost to the situation, not to mention fuel costs without some sort of OD manual transmission in the mix, too, which will be even more expense to make that happen. Everybody has their own sensitivities to these things, which I respect. Your car, your money, your time, your desires . . .

Enjoy!
CBODY67

 

[NitrousTuner1]

Comp cam & MOPAR = NO THANKS
Chrysler & AMC use a very large lifter base which is much heavier than the bandwagon GM & Ford's. That being said there's manufacturers that specialize in MOPAR power. Comp is not 1.
I'd call Schneider, Cam Motion, or Bullet... Comp uses many blanket grinds across the board... Use technology to your benefit

 

[70bigblockdodge]

If you are going to go with a roller the specs can be less on the duration (lift is not determined by lifter design) and perform the same. This is possible because the lifter can be opened faster, giving you more lift during the time the valve is open. Think of a roller as snapping the valve open very quickly and flat tappet opening slower, this is in layman's type terms.
You could use either style for relatively mild application.