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Which camshaft for 350 CID engine with Weiand 144 supercharger?
I am looking for a roller camshaft for my marine project (21ft Wellcraft) 350 CID engine (overbore 0.030").
Important: acceptable idle, good performance, fuel min. 95 octane, CR about 8.5:1 Any ideas? ![]() Andreas |
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here are my heads:
cylinder heads SBC Victor jr. Edelbrock 77589 complete combustion chamber volume 64cc intake valve 2.08" exhaust valve 1.60" intake runner volume 215cc exhaust runner volume 85cc |
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I run an Edelbrock RPM cam lifters,push rods, RPM Heads, and roller rocker arms. Love them. 18k + miles. Purrs like a kitten at idle and pulls hard to as fast as I like. I red line at 5500 but it will go higher.
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In picture 2 I assume you are showing that the skirt has been broken off the piston. I'd replace all 8 with forged pistons for the boat use. Arp rod bolts min. Consider 4340 rods if you run a lot at high speed.
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Two threads, same subject, merged.
__________________
Horsepower is how fast you hit the wall. Torque is how far you take the wall with you. Midnight Sun Street Rod Association |
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What can I expect as save idle (important for onshore boating) with these cams (without losing high rpm power):
#119821 #119831 #119701 #113821 Crane, Comp Cams, other... your recommendation? Which cam is the best compromise? |
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With my combination the idle is about 950 in neutral and 750-600 in gear. I guess in a boat you would see little drop at idle. If you use a single carb there is no real need for a very hot cam. The blower will smooth out the cam roughness especially at idle. Assuming you have the dist curved correctly and the carb adjusted right.
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All those crane cams will run well. The little one makes a bit less power.
The idle and low speed performance is no problem with any of these. A low 7.5:1 compression ratio allows more blower boost and reliable power. Get deep D dished pistons. If using marine exhaust manifolds get the good Mercruiser Magnum manifolds or equal quality replacements. Port match to your heads exhaust ports. |
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Of the Crain cams F-bird suggests, For your app....boat off shore, I'd go with the first one...119821. You only have a single 750 and a small blower so there is little point in tuning for high rpm. Excess of 5000. You simply will not be able to provide enough boost to make it worthwhile. These small blowers don't make the low speed punch that a 6-71 will even OD'ing them higher.
A boat starts off with a big load at load at 2500-3000 rpm so you really need the power here. Your boat is no flyweight and not really designed for 100 mph speeds. Pulling 5 skiers is a heck of a load so I'd prop for 5000+ at 70 mph I'd tune for max of 5000 to 5500 WOT no skiers. your motor is gasping at this speed. F-Bird suggests using very low comp pistons...I agree. You will be running on marina gas which is probably 87 on a good day so essentially as I do run on reg gas. Everything needs to be right however and just because you have low comp does not mean burned pistons are a thing of the past. If you go lean under full power you better have a good paddle. The heads will be fine...I wish I had them. the 64 cc chamber makes a deep dish piston mandatory. I think there is only one -22 cc piston available unless you go with forged ones. |
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