blower cam recommendation.
 

Hello,
I am helping a buddy with his motor and he has decided to get away from the solid roller cam that was in the motor when he bought the boat. He really doesn't care how fast the boat is and wants something reliable with no maintenance. He also doesn't want to spend a ton of money. I think a hydraulic flat tappet blower cam is just the ticket for this application. Here are the motor specs. 468" BBC, 8:1 compression, 990 heads with pocket porting, CMI Etops, B&M 420 with 2 stage 5 Nickerson 850's. He only ran 5 lbs of boost previous seasons. No head flow info is available. I would like to cam the motor to run in the 5500 - 5800 RPM range at WOT. Anybody have a recommendation?

Thanks,

Craig

Re: blower cam recommendation.
 

I'm surprised you're not looking at one of those Crane Hydraulic rollers. Summit has a nice little 228/ 238, .540 lift, 114, flat tappet.

Re: blower cam recommendation.
 

How about the factory 600sc cam, I know its from a little larger cube engine but it gets my vote. Lift is .553/.571 and can be ordered new from Crane pn134561. Blowers Rule! :drink:

Re: blower cam recommendation.
 

Anyone know the specs on the cam B&M had ground for a marine application? Greencard, what is the duration on the 600 SC cam?

Re: blower cam recommendation.
 

Craig,
Here are the specs on the 600 SC cam:
Crane single pattern
Lobe H 240/329
300/300 @.0042
240/240 @ .050
148/148 @ .200
.559/.559
105 ICL
115 ECL
110 LSA
INTAKE 43 BTDC 77 ABDC
EXHAUST 83 BBDC 37 ATDC
Bob

Re: blower cam recommendation.
 

Craig,
There were 2 different cams used in the 600sc, I believe the early version is the specs RM listed and the later is the same but w/244/244 duration and the staggered lift I listed. The pn I gave is the same as what was in :rolleyes: "Team Eliminators" '98 600sc's when we took them apart. I did some research with Crane because I thought about them in mine.The B&M cam is also similar to the one I listed but on a 114 and also is a Crane grind. B&M used to have 2 generic blower cams listed in their old tech literature if you can find it, the more radical one is the one you want to check out.After all this I must tell you the 454 in my old 22daytona had 8.75 compression, gm heads ,B&M 420 w/750's and a hydraulic 741 crane and made 689hp at 5psi on the dyno at at 6100. Good luck :drink:

Re: blower cam recommendation.
 

How well will the 600 SC cam work in a twin turbo intercooled 454? Had to rebuild one motor from detonation last years and since I have it completly apart want to maybe put in new cams.

Re: blower cam recommendation.
 

Craig,
Just to clarify
The 2000-2001 575 SCI
1991-1996 Gen IV/V 600 SC
1998 Gen VI bobtail 600 SC
1993-1998 800 SC
All run the Crane/ Merc # 491-818870 cam I listed above
The 134561 is a Crane catalog cam. It is a dual pattern that specs as follows:
296*/306* @ .0042”
236*/246* @ .050”
144*/154* @ .200”
.553”/ .571” lift valve
109* ICL
119* ECL
114* LSA
Crane does not have any 244* @ .050 flat lobes in their master
Is your friend locked into a flat tappet? From a performance and durability standpoint a roller is a very good investment. The new Morel limited travel hyd-roller lifter also provides many of the benefits of the solid roller with the convenience of a hyd-roller.
Bob

Re: blower cam recommendation.
 

RM,
He has been running a solid roller for the past couple of seasons. His motor is due for a lifter change so someone else took the intake off and dis-assembled the valve train for him, and I was going to re-assemble with new lifters and rockers. When I saw the lifters I immediately suspected the cam was going to need to be replaced at which time something requireing less maintenance could be installed. The lifter wheels are marked up pretty bad. It appears some contamination went through and pitted / galled a couple of them. I finally got to take a good look at the cam today and it appears to be fine. Now I am curious if the lifter wheels are slightly softer than the cam allowing the cam to not be damaged by whatever went through the motor? If we get away from the solid roller the motor will need to be pulled, at which time I will highly recommend our local engine shop tears the motor down for a good inspection and cleaning to assure no more junk is floating around. Then a hydraulic cam can be installed for less maintenance. Cost is the biggest reason for just going to a flat hydraulic stick for him. He is on a budget and doesn't really care about 50 HP if it will save him $$$$. This is one of those "buddy system" projects that I really don't have much time for!! In reality this guy needs a nice stock motor that won't give him headaches. That is one option I will be discussing with him.

Craig