Which Cam???

[mickeyfinn]

I posted this last year and have never gotten to complete the engine. All I lack completing the engine is the cam. It is a 402 chevy with forged pistons. I want to build it to be pretty reliable so I don't want to stress it all the time. I am looking for 5500 - to 6500 RPMs. I will be running a 750 dual line double pumper carb and am thinking a 100 or 150 shot of laughing gas on rare occasion. I want to be able to use the nitrous for a little extra top end rather than better accelleration. Thinking the carb setup with the prop I have is probably good for about 5500-6000 RPMs Would like to push 7000 occasionally with the gas. Anyone have a good recommendation for a cam that will work for this and what should I look for in preventing reversion?
Thanks,

[396_Z]

I'm building an almost identical engine for flattie. For mine I chose a comp XE274, however I'm thinking I should have gone up into the mid-280 range. (maybe even as high as the XM298)
All of the XE's run a 110 lobe sep angle where the XM's are 112.
Let me know how you like whatever you end up choosing, it may help me out alot.

[Kindsvater Flat]

Originally posted by mickeyfinn
I posted this last year and have never gotten to complete the engine. All I lack completing the engine is the cam. It is a 402 chevy with forged pistons. I want to build it to be pretty reliable so I don't want to stress it all the time. I am looking for 5500 - to 6500 RPMs. I will be running a 750 dual line double pumper carb and am thinking a 100 or 150 shot of laughing gas on rare occasion. I want to be able to use the nitrous for a little extra top end rather than better accelleration. Thinking the carb setup with the prop I have is probably good for about 5500-6000 RPMs Would like to push 7000 occasionally with the gas. Anyone have a good recommendation for a cam that will work for this and what should I look for in preventing reversion?
Thanks,
This is a good question to ask Fiat 48 with his cam program. He can spec one out for you.

[Fiat48]

Originally posted by Kindsvater Flat
This is a good question to ask Fiat 48 with his cam program. He can spec one out for you.
Well, yes and no. I'd have to know a lot of measurements you probably do not have. I don't like guessing and the last thing I want is to tell you some cam that may not work well for what you want. So unless you really want to do some work and also flow a cylinder head for flow numbers, best bet would hope someone has a similar combination and same application you do. Or rely on the one of the cam grinders...or contact several and compare results. See who is on common ground.

[Moneypitt]

Planing a low maintainence BBC is easy, until you say 7000!! Now everything changes, big time. Granted the juice will give you a boost of power, but the valve springs don't accept laughin' gas as an additional coil. If you're gonna squeeze it, you better get the valves closed. Failure to do so will create a little more power than your induction system can handle, called an explosion!!! Now, to close those valves at that type rpm you are talking some high spring pressures, which in turn require roller lifters, which require a roller cam profile. So your simple "just lacking a camshaft" project i$ now needing quite a bit more, roller rockers, stud gurdle, etc. Aint this shit fun????...Moneypitt

[mickeyfinn]

The Cam I am looking at now is a 5500 rpm cam with valve float at 6500. I am hoping this means that I can prop to run 5500 without the gas and then use the gas to get me the extra little oomph to maybe get the last 500-700 rpms.

[SUI-CY-COLE]

call engle cams in socal...they make good cams for that range you are talking about....ask the people that build and use them for a living.

[Fiat48]

Originally posted by Moneypitt
Planing a low maintainence BBC is easy, until you say 7000!! Now everything changes, big time. Granted the juice will give you a boost of power, but the valve springs don't accept laughin' gas as an additional coil. If you're gonna squeeze it, you better get the valves closed. Failure to do so will create a little more power than your induction system can handle, called an explosion!!! Now, to close those valves at that type rpm you are talking some high spring pressures, which in turn require roller lifters, which require a roller cam profile. So your simple "just lacking a camshaft" project i$ now needing quite a bit more, roller rockers, stud gurdle, etc. Aint this shit fun????...Moneypitt
LOL! And then you could go faster if you just had better heads and a sheet metal manifold but that costs as much as a blower so you might as well go blower and then might as well go injection and alcohol is cheap and all you gotta do is change the nozzles and that don't cost much:rolleyes: and it keeps on going!!!:D

[Blown 472]

Howards in oshkosh, wi does nice work too.