If I'm making a custom grind for my slant six, should I have more duration on the intake side and lift?versus the exhaust side, I'm running split manifolds into a y pipe. No header. Thanks let me know what you guys think.

Yes, generally the 225 likes more intake duration than exhaust. It appears that 4-8 deg @ 0.050" more on the int is what works.

Lou

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Home of Slant6-powered fun machines since 1988

Thanks Lou going to be putting a custom 268 .470 lift intake 264 .460 lift exhaust in my four speed

Sounds great. I would recommend 9:1 compression for that kind of cam. Can you list the duration at 0.050"? What are the other engine parameters (bigger valves, induction...)?

Lou

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Home of Slant6-powered fun machines since 1988

Yeah sure 230 236 @ 50, yes my motor is at 9:1 I'm currently running an Avs 500 cfm carb, the valves are stock but I have another head that I'm going to port out a bit and install some ford intake valves. I currently have the Howard's 256 .473 but she runs out of steam at 5k, I believe I under cammed my motor to my liking. I originally had 264 clifford 474 lift camshaft. I lost some top end for sure swapping almost 10 durations less. I mean the car is fast but I know with this new camshaft I'll be happy were I'm at. Hopefully lol.

For better power overall and a maybe bit less low end (and a bit rougher idle), set your lobe separation angle (LSA) to 106 deg. I do this for all my perf cams. Degree the cam at 100 installed centreline - best power overall AND better lower end than what most manufacturers recommend (104 or 108 or whatever).

A big valve head with even mild bowl porting will make a big difference over a stock head. Lots more top end, and no sacrifice in low end.

Lou

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Home of Slant6-powered fun machines since 1988

more power rougher idle! looks like 106LSA it is! sending the camshaft out tomo to get regrinded.
So Lou what do you think about the Howards 256 .473 lift camshaft i have? i feel like this is a RV Truck camshaft vs performance.

It is hard to know how it (Howards Cam) will fare, performance-wise, until you get a good flowing head on the motor. Yes, I would say it is on the mild side and the LSA is large so bottom end and smoothness will be emphasized. I just bought one of those and will run it (sometime this summer) in an engine intended for supercharging. It will have a high flowing head on it. Will let you know how it feels.

Lou

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Home of Slant6-powered fun machines since 1988