another camshaft thread

[Tooloe]

ok well i have searched an still havent really found my answer..my motor is being rebuilt an its time to order the cam i want...heres my problem..i dont know what is the best cam for my set up..alot of people sware by the comp coupe cam..but i dont like the idea of paying 300 bucks for 10 or so extra HP...so i guess heres my question whats the best performing camshaft for our trucks?...i would like to have a lope to go along with performance..an the cam will be tuned with an sct tuner. so tuninng shouldnt be a problem...an my head are also slightly ported an the motor is completely portmatched... any ideasfrom the gurus on this foum...



i know my sig says comp coupe cam..but im unsure if thats the best cam for my set up

 

[BurntRubber]

708 cam found in gen II vipers
or contact PBJ

 

[rottenronnie]

ok well i have searched an still havent really found my answer..my motor is being rebuilt an its time to order the cam i want...heres my problem..i dont know what is the best cam for my set up..alot of people sware by the comp coupe cam..but i dont like the idea of paying 300 bucks for 10 or so extra HP...so i guess heres my question whats the best performing camshaft for our trucks?...i would like to have a lope to go along with performance..an the cam will be tuned with an sct tuner. so tuninng shouldnt be a problem...an my head are also slightly ported an the motor is completely portmatched... any ideasfrom the gurus on this foum...



i know my sig says comp coupe cam..but im unsure if thats the best cam for my set up

The trouble here is the cam that comes with these engines is very closely matched to the capacity of the o.e.m. heads (which is one thing you want to do when choosing a cam anyway) as well as the rest of the engine's specs- (compression ratio, etc.). That is why there aren't any substantial gains (10 to 15 horsepower?) in changing it for another one WITHOUT making more in-depth changes to your engine (in a naturally aspirated application). For example, it makes little sense to install a big lift cam (.700") if the heads stop flowing at .550"

After you make some more "serious" changes, say a head swap or a good port job, an increase in compression, etc; you can consider a different cam. Then a cam swap will make a worthwhile improvement as it is now able to work with the engine changes that were made.

I'm not sure what changes you have made during the rebuild, so these are pretty general statements.

I you really WANT a cam, something close to the coupe cam/the "708", as suggested by BurntRubber, could be a good choice. Otherwise, the cam that you have is probably close to the allusive "best" cam for a heavy pump gas truck in street use.

No big power improvements with a simple cam swap with the engine close to stock 'cause the stock one just ain't that bad. Remember the Viper engine is a performance engine to start with!

Hope this helps...

 

[Tooloe]

yes that makes perfect sence....an i honestly dont know what my heads flow since the port job..an valve work..hmmm well that pretty much answers my question! thanks guess i should ask the guy to flow my heads..an see what cam best suits me then.

 

[rottenronnie]

yes that makes perfect sence....an i honestly dont know what my heads flow since the port job..an valve work..hmmm well that pretty much answers my question! thanks guess i should ask the guy to flow my heads..an see what cam best suits me then.

Sure, ask around and choose a cam that builds torque (cylinder pressure) rather than one that forces lots of r.p.m. to make horsepower.
The "lope" you are after is very close, even with the factory cam (but it hides somewhat under those high bleed down lifters that don't allow for full cam specs. @ idle).

Sometimes with a choice between 2 cams, less is more.

There are builders far more familiar with this engine than I am but if you have time, ask around before making your decisions. Hopefully you won't get a lot of conflicting data!
At the risk of inviting the wrath of the Viper Gods, engines are engines and the majority of what applies to one, works for the other; especially the basics like this. Unless of course you have figured out how to ignore physics and make engines work well some other way.

These engines seem to respond well to an increase in compression as well. You will automatically gain around 1/4 point in compression by going to the new gold coloured gaskets that are used on the 2008 Vipers; A gasket crush of .039" vs. .053" with the original older black gaskets.
It doesn't cost much to have your heads cut to raise the compression a bit now that they are off. I am not sure what your altitude is where you're at but 10.25 to 10.5 with good fuel shouldn't be a problem. And, you have a manual trans; so even better.
Sorry for the long post but I love this stuff!!

 

[Tooloe]

dont worry about the long post..i love learning about this stuff..this will be the 2nd time my heads will be shaved so i should see a nice raise in compression....i honestly could care less about the lope its just a bonus of being cammed i just want the best performing motor i can have without spend thousands of $$$

 

[ZCx]

Sean @ Roe. Kevin @ Exotic Engine. Justin @ JMB Performance. DC Performance. PBJ, etc.:rock: :rock: :rock:
if ya want ya motor to be more powerful, just give it more volts. 220 221 what ever it takes:rock: :rock: :rock: