You got it!
.480/230 cam in an 8.5 CR 360?
- Thread starter fshd4it
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junkyardhero
Well-Known Member
iffin' you're gonna run that cam, i'd advance it as suggested. but as others have noted with that combo: low compression, blah stall, no gear and heavy car-- you've got a recipe for dog water. though, it'd probably run pretty good at highway speed.
there's nothing inherently wrong with that cam, but if you're looking to swap it i personally think that there's many other, more modern grinds out there that are much more suitable to the task at hand.
there's nothing inherently wrong with that cam, but if you're looking to swap it i personally think that there's many other, more modern grinds out there that are much more suitable to the task at hand.
If you REALLY want a first hand understanding, here's what you do. With the engine assembled and timing cover off. Rig up some sort of starter mount. A manual bellhousing with a flywheel will work. Degree the cam straight up at 109. That's even with the lobe center. Now, get a compression gauge and measure cranking pressure in #1 and record it. Now advance the cam timing down to 100 ICL and get a cylinder pressure reading there. You will see the difference for yourself. It will not be accurate unless you degree the cam to 109 FIRST.
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I don't think it'll be "that bad". I recollect a LOT of us ran big hydraulic cams straight up in low compression motors when we were kids and didn't know any better. They sounded great in the high school parkin lot. They pulled good too startin about 4k. LOL
junkyardhero
Well-Known Member
it's survivorship bias.
also you old farts can't remember what you had for breakfast let alone fiddy years ago!
(i keed, i keed)
Good. So that means when I get my CR sorted, I'll be back to talk more about how much I should bump the cam forward. However it works, I'll shoot for at least 9:1, or more if that's how the parts work out. And acquire an adjustable timing chain set, as this one's not.
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Hush up fool. lolit's survivorship bias.
also you old farts can't remember what you had for breakfast let alone fiddy years ago!
(i keed, i keed)
At 9:1......a MEASURED 9:1 and not "bench racin" 9:1, I'd go 4 degrees advanced. That would be 105 ICL.
Those would be a No Brainer for me. Deep port the flanges of the performer intake to match a set of 1243 Fel-Pro gaskets (theyr'e a performance intake gasket for a 273/318, but they match a J head's intake ports well), and install the cam on a 105 ICL. The compression boost and low lift flow with 2.02 J heads would work pretty well. It would certainly work some better with the high gears and somewhat tight stall.
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When you are at 8.5:1 with a cam designed for 10:1 CR; more compression will definitely help. And it will help throughout the rpm range. Some modifications do not do this....
Once you increase the CR, I would advance the cam to 104-105 ICL. This increases low end tq by closing the int valve earlier & trapping more air.
You will need to check valve to piston clearance before doing these mods. I doubt there would be a problem, but best to check.
Once you increase the CR, I would advance the cam to 104-105 ICL. This increases low end tq by closing the int valve earlier & trapping more air.
You will need to check valve to piston clearance before doing these mods. I doubt there would be a problem, but best to check.
BSB67
Well-Known Member
Agree with most posts, increase CR, advance cam.
But, at this point maybe consider a regrind of the cam and resurface of the lifters. That cam would probably work as a good core to grind something better suited for your application. I get that budget matters but maybe price it out.
But, at this point maybe consider a regrind of the cam and resurface of the lifters. That cam would probably work as a good core to grind something better suited for your application. I get that budget matters but maybe price it out.
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