cam size?
- Thread starter 1BADBIRD
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1BADBIRD said:
Everyone's interpretation of "Street Usage" is different...depends on what you're willing to put up with in terms of driveability (bigger cams sometimes mean steeper gears), idle characteristics, vacuum, etc... I think John down in Texas is running something with similar specs in his 440-6...John feel free to chime in... To me, that is not too big for the street - YOU may think differently after installing it depending upon what your preferred camshaft attributes are...
Ray
mcmopar
Well-Known Member
1BADBIRD said:
It depends on the rest of the setup. Its a little bigger than I would (did) go but if you have the rest of the pieces in place (converter/gears/heads/headers, compression, etc) it wouldn't be too bad - in a 440. That might be just a tad much for a 383. The cam in my 383 is a Comp XE275HL-10: 231/237 @ .050 with .525" lift on a 110 degree c/l but with the 1.6 roller rockers it nets a .560" lift. I pull 10" of vacuum at idle so be aware that with your cam selection you'll not get much better. You'd better have at LEAST 9.5:1 compression with a cam that big. 10.5:1 would be preferrable. You are going to bleed off a good bit of cylinder pressure with a cam that size so you need a good bit of compression to keep things popping. Too little compression and your car will act like a tired old dog.
Please post the rest of your combo so we can have a look at it with you - and don't forget to call your cam manufacturer's tech line and get some input from them. They usually know what they are talking about.
george68hemirr
I think you guys are full of shit.
1BADBIRD said:
i think you should call the cam people up and tell them everything you have in your car...how you drive it and how fast you want to go and they should fit a cam to your specs for the street......my little cam is a 283 duration with a 700 lift....very radical street cam.....its how radical you want to go....then is it a flat tappet/hyd/or roller cam
Comp is 11:1 heads are milled,ported 906s Rockers are 1.6 rollers from crane. This is the engine I am building for my six bbl setup. MSD ignition, I used a factory steel crank, eagle H-beam rods, ross pistons with 60. overbore 440. let me know what you think. :cheers:
Also figured I would add its a 4 speed car with 4:10 gears and headers.
Also figured I would add its a 4 speed car with 4:10 gears and headers.
mcmopar
Well-Known Member
That's a nice stout setup that should work well with that cam. Lots of compression and gearing. Just remember that with your 1.6 rockers your net lift will go from .557" to .594" so make sure your valve pockets in the pistons are deep enough to give you .100" - .120" of piston to valve clearance.
69hemibeep
Sponge Bob Square Wheels
Sounds like a nice combo1BADBIRD said:
george68hemirr
I think you guys are full of shit.
.thats what you have to watch is piston to valve clearances...which you can check with clay on top of your pistons...if it dont work you can also play with differant head gaskets since your compression is a 1/2 point high for 93 octane....10.5 is the max for cast iron block and heads...if you had a cast iron block and aluminum heads you could go 11 on compression....mine is aluminum block and heads...11.5 to1 comp for 93 octane.....1BADBIRD said:
SomeCarGuy
Well-Known Member
That should be a nice combo, but it may take a can of octane boost.
I thought that for pump gas to work it was 9.5 for iron and 1 point higher for aluminum heads?
I thought that for pump gas to work it was 9.5 for iron and 1 point higher for aluminum heads?
mjoyner408
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why can you run higher compretion ratio with alum heads vs. cast iron? 10.5 is ok for 93 with iron heads? i thought 10 and above = detonation
george68hemirr
I think you guys are full of shit.
mjoyner408 said:
SomeCarGuy
Well-Known Member
A Hemi can run a bit more than a wedge on pump gas. Chamber is beter.
mcmopar
Well-Known Member
The aluminum heads dissipate heat faster and can therefore take a little more compression. Heat and compression = bad for the crap fuel of today. Funny thing is I'm running around 10.5:1 c.r. with 452 iron heads and TRW L2293 domed pistons (11:1 c.r. rating with stock combustion chamber size) but with my timing set the way it is I'm running 87 octane without any ping when I tromp it. It will knock a bit at low speed if I loaf it off the line, though. I should run at least 89 octane but its doing ok for now and I'm cheap! :drive: (<- Mr. 4 Speed)
The pistons were massaged by the builder who put it together for one of the previous owners. They have had all the sharp edges smoothed off so as to diminish the possibility of detonation. Whoever built this engine back in the '90's knew what they were doing.
The pistons were massaged by the builder who put it together for one of the previous owners. They have had all the sharp edges smoothed off so as to diminish the possibility of detonation. Whoever built this engine back in the '90's knew what they were doing.
John69RR
Well-Known Member
Been away for a few days and just read this. Yes my cam is similar. I have a 256@50,551 I/E lift. I'm also using the 1.5 Crane ductile iron rockers. My engine is a 400 stroked to 452 with 88cc Edelbrock heads, 10.3 compression, and 3.55 gears. I'm thinking about some 3.73's. 3.91 is a bit too much on the street with 14" tires.
SomeCarGuy
Well-Known Member
I don't think you will see much change with the 3.73 set. 3.55 would be noticeable I think.