cam profile

[lhovan49]

a question for the jet junkies. what is the difference in cam profiles from a jet motor, to a good street strip cam? I know there is one just don't know the difference. Not being the brightest bulb in the barn, I need to ask the ? Thanks to all in advance

[Stv Euro]

What I have found out is that the Jet cams all work on certain bans of rpm's. For example my cam is a Mondello Jet boat/Bracket racer cam that works on the upper rpm range. The jet boat cams have to be big but not so hugh that the bog when coming out of the hole. Also jet boats usually run from 3,000 rpm's and up. Go to MSN and search under Mondello, when you open it look on the left for engines or cams and open. He has a great list of all cams and maybe you will be able to see the difference betwen a "car cam and a jet cam" they will all be listed there for you.

Maybe this will help. Later

[sho305]

I was working on some BBC I/Os, that I'll assume are similiar in that they pull up to 3.5k and on up to 6800rpm we ran. The trick seemed to be to have the torque curve flat and extend into higher rpms. I believe they had less overlap, I think. We were around 500hp with a 454ci. Tried lots of cams and finally, you guessed it, used a Merc cam. It was the 465 and I think a take out from a 502 at the time. You had to use the expensive special Merc springs or it floated; so the profile must be hefty. Had to have good bowl ported heads, and the hogged oval darts were better mid than the rectangles and about the same top end. We used a ported performer rpm, and a dart intake was a hair more top end but you lost in the mid range. Was a good trade off for a large vee we ran them in that needed torque to get up and also run well at medium speeds. Brutal 1000 rpm idle. Idled nicer with bleed down lifters, but that was not the idea:D

On the cheap, it was a great combo with the cam and carbs off a 502 on a 454 with good heads/etc. Would be awesome in a big 4x4 truck, but you would want more high rpm pull/range in a car for example. Maybe there is better stuff out there now as this was maybe 10 years ago, but they worked well and ran about even with 525 Merc stock blower motors and took less fuel. Pure music at idle though. I think they dynoed at 480hp in marine garb, but then after breakin they went up three jets and ran more speed and rpm. I'll guess a jet needs more emphasis on peak power from what I remember riding in one, as it seemed to get close to top rpm when ever you hammered it while on plane.

[waterslinger]

torque curve is the key. Most jet cams have a 108 or 110 LC. Earson and Comp have some jet cams.