Small Block Chevy Camshaft Question

Hello:

I am trying to select a camshaft for the 327 engine in my 18' Pachanga (weight w. motor ~2,300lbs). The freshly rebuilt short block has the GM 3863151 cam (221/221 @.050 duration, 447/447 lift and 114 deg centerline) already installed. The heads will be stock 1.94/1.50 units. Will this camshaft be suitable in my setup or should I go with the GM 12353918 "marine" cam or ??

Thanks, Jack

[Full Force]

What is the compression,if it is under 9:1 keep the cam you have,I did cam work this winter,I talked to cam-motion for advice,they make custom cams,I was told if you have low compression keep the duration down or you will lose all your low end,lift is not as much as an issue as most think,especially with stock or close to heads,I have darts on mine and run 450 lift. duration on m,y 350ci with 8.5:1 is 212/218 @.50

UPDATE:

Just wondering what the consensus is on the Comp Cams Xtreme Marine 262H (218/224 @.05, 462/477 and 112 deg lobe centerline?

Thanks 245...

The compression ratio should be 9.5 or 10.0:1. I was reading the specs on that 151 GM grind and what concerned me was the power range which is 2200-5200 RPM. Seemed a little high...might be giving up some bottom end grunt?? Whereas, the Comp Cams 262H (referenced in my last post) has a power range of 1300-5500. Will this even be a concern on such a light boat with excellent power-weight ratio?

Jack



1970 18' Sea Ray Pachanga

[jmherbert]

That may be a little big for a 327 running stock heads. Remember when reading mfr's descriptions that they are meant for 350's unless otherwise noted. More cubes like bigger cams, and vise versa.

[Full Force]

Originally Posted by theinterceptor

Thanks 245...

The compression ratio should be 9.5 or 10.0:1. I was reading the specs on that 151 GM grind and what concerned me was the power range which is 2200-5200 RPM. Seemed a little high...might be giving up some bottom end grunt?? Whereas, the Comp Cams 262H (referenced in my last post) has a power range of 1300-5500. Will this even be a concern on such a light boat with excellent power-weight ratio?

Jack



1970 18' Sea Ray Pachanga

I did a ton of reasearch on this,see may old posts here over winter,I would keep it small and simple,you only have 327 CI so a big cam will kill the bottom end,it is a light boat yes but you are trying to go through water,hard to do.
I think something in the 212-218 range will prob be best with small CI. The stock style heads do not flow alot so too much cam will lose all torque.I have dart heads and I still have a smaller cam due to the 350 ci, if I had a 383 or 400 I could go alot bigger,also more compression.
I will proib build a 383 this winter to use the dart heads I have,I used them since I got a smokin deal on them.

Ok, 245

If I go one step down from the Comp Cams 262H and use the 256H the specs are almost identical to what you recommend:

212/218, 447/462 and 112 deg centerline and power range of 1000-5000RPM

[SB]

Be careful with cam selection, especially if you are around 10:1.

Many of the 'small' cams have earlier IVC events that will also boost cylinder pressure.

[Full Force]

Originally Posted by theinterceptor

Ok, 245

If I go one step down from the Comp Cams 262H and use the 256H the specs are almost identical to what you recommend:

212/218, 447/462 and 112 deg centerline and power range of 1000-5000RPM

That is about what I have,same duration,I have a little less lift,I would contact cam-motion and have them suggest something just to make sure we are thinking the same.