Can anyone recommend a good streetable hydraulic roller camsahft (brand and grind specs) for a 1967 427 engine, with either 10 to 1 or 11 to one compression? I'm thinking something with a maximum lift of .600 and duration perhaps in the 280 degree range??????? Not sure about these numbers, so I need some help. Axle ration will be 3.70 Thanks, Rex #8089
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Re: 1967 427 roller camshaft
contact a cam co.like comp cams,with all your specs and they will tell you what will work -
Re: 1967 427 roller camshaft
contact a cam co.like comp cams,with all your specs and they will tell you what will workComment
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Re: 1967 427 roller camshaft
Rex-----
In addition, DON'T "over cam" the engine. If you want to have a nice, streetable engine that's pleasant to drive and will do the best by you 99% of the time, you don't want to go too wild. If all you want to do is a little around town cruising once-in-awhile, you can go wilder. Personally, I wouldn't, though. I like something that's reasonable out on the highway where Corvettes belong.In Appreciation of John HinckleyComment
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Re: 1967 427 roller camshaft
Rex-----
In addition, DON'T "over cam" the engine. If you want to have a nice, streetable engine that's pleasant to drive and will do the best by you 99% of the time, you don't want to go too wild. If all you want to do is a little around town cruising once-in-awhile, you can go wilder. Personally, I wouldn't, though. I like something that's reasonable out on the highway where Corvettes belong.In Appreciation of John HinckleyComment
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Agree with Joe
If your plan is for a street driver with stock exhaust and mufflers, you loose a lot of the benefit of a radical cam. Racing with open headers is a different story. Since a long duration cam lowers your dynamic compression ratio, builders frequently run 10:1 or 11:1 with those cams.
For a street motor, remember, big blocks are much less tolerant of high compression than small blocks. While there are many 350's running near or at 11:1 on pump gas, 10:1 is really pushing it for a big block. I have personally made this mistake on more motors than I care to admit to (took an engine builder's advice, later found out all the other people with those motors are adding av gas) can you say SLOW LEARNING CURVE! The best example I can give you is my 489 cu in L89 vs. my wife's 454. Mine has 10.3:1 with closed chamber original aluminum heads with a full stock type exhaust and a longer duration cam (I 245 at .050). Hers has 9:1 with a shorter duration cam (I 221 at .050) but with well-ported 781 casting open chamber heads with oval ports and 2.25 I and 1.88 E valves, running a stock exhaust.
Mine will run OK on pump 93 octane but even after months of tuning, still diesels when shut off unless I add a few gallons of av gas to each tank. Hers runs GREAT on 93 octane and has plenty of vacuum to work all the accessories. In addition, in a heads up race with me running 3000-6000 RPM and her running 2500-5000, I can pass her, but if she gets a head start, I don't blow her doors off by any means. Remember, the stock exhaust is RESTRICTIVE and really affects engines with a longer exhaust duration more.
Good luck,
MarkComment
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Agree with Joe
If your plan is for a street driver with stock exhaust and mufflers, you loose a lot of the benefit of a radical cam. Racing with open headers is a different story. Since a long duration cam lowers your dynamic compression ratio, builders frequently run 10:1 or 11:1 with those cams.
For a street motor, remember, big blocks are much less tolerant of high compression than small blocks. While there are many 350's running near or at 11:1 on pump gas, 10:1 is really pushing it for a big block. I have personally made this mistake on more motors than I care to admit to (took an engine builder's advice, later found out all the other people with those motors are adding av gas) can you say SLOW LEARNING CURVE! The best example I can give you is my 489 cu in L89 vs. my wife's 454. Mine has 10.3:1 with closed chamber original aluminum heads with a full stock type exhaust and a longer duration cam (I 245 at .050). Hers has 9:1 with a shorter duration cam (I 221 at .050) but with well-ported 781 casting open chamber heads with oval ports and 2.25 I and 1.88 E valves, running a stock exhaust.
Mine will run OK on pump 93 octane but even after months of tuning, still diesels when shut off unless I add a few gallons of av gas to each tank. Hers runs GREAT on 93 octane and has plenty of vacuum to work all the accessories. In addition, in a heads up race with me running 3000-6000 RPM and her running 2500-5000, I can pass her, but if she gets a head start, I don't blow her doors off by any means. Remember, the stock exhaust is RESTRICTIVE and really affects engines with a longer exhaust duration more.
Good luck,
MarkComment
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Re: Agree with Joe
The biggest problem with most aftermarket cams is too much overlap. They're typically ground with centerlines of 110/110 for a LCA of 110. This narrow a lobe center with typical duration will kill low end torque without returning anything on the top end. OE type exhaust manifolds cannot effectively use much overlap. It takes headers and very low restriction exhaust systems or open exhaust to effectively use the amount of overlap in aftermarket cams.
The vintage OE SHP cams typically have 220-230 degrees duration at .050" lifter rise with inlet centerlines in the 108-110 range and exhaust centerlines from 118 to 122 range, which yields LCAs of 114-116, not 110 like a typical aftermarket cam.
Modern Gen III and IV Corvette engines use aggressive roller cams with only about 205 to 210 duration at .050". In addition the inlet cams are phased much later with centerlines in the 115-120 ATDC range. Exhaust centerlines are about the same BTDC so LCAs end up near 117 - virtually NO overlap, but a relatively late closing inlet valve to use inlet inertia to achieve high VE at high revs.
DukeComment
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Re: Agree with Joe
The biggest problem with most aftermarket cams is too much overlap. They're typically ground with centerlines of 110/110 for a LCA of 110. This narrow a lobe center with typical duration will kill low end torque without returning anything on the top end. OE type exhaust manifolds cannot effectively use much overlap. It takes headers and very low restriction exhaust systems or open exhaust to effectively use the amount of overlap in aftermarket cams.
The vintage OE SHP cams typically have 220-230 degrees duration at .050" lifter rise with inlet centerlines in the 108-110 range and exhaust centerlines from 118 to 122 range, which yields LCAs of 114-116, not 110 like a typical aftermarket cam.
Modern Gen III and IV Corvette engines use aggressive roller cams with only about 205 to 210 duration at .050". In addition the inlet cams are phased much later with centerlines in the 115-120 ATDC range. Exhaust centerlines are about the same BTDC so LCAs end up near 117 - virtually NO overlap, but a relatively late closing inlet valve to use inlet inertia to achieve high VE at high revs.
DukeComment
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