to many choices
Thread Starter
Melting Slicks
Joined: Dec 2000
Posts: 2,130
Likes: 1
From: mesa,az
to many choices
I was talking to the guy doing my RHS heads last night. I had brought over my RPM manifold so he could set it up with the heads. I have been planning a 383 but we got to talking. I told him I got the giggles listining to the small block above 6000 RPM and I was replacing it cause it just can't go higher on a reguler basis ( cast crank, stock rods, KB pistons. ) I have deep gears in the 65 with a 5 speed. We talked about having to change the gears etc and he asked why I just don't build an 8000 RPM 327. Well I don't know . Why not. The car is a total toy and I love winding it up. Anyone here ever build something like that. I have bought another 327 engine from a coworker so I can use a non originial block. Ventilating it won't be a major deal, I mean a pain sure but no major loss of value. What do you guys think about it. a screaming 327 or a grunting 383. If it matters my other project is a blown BB, but that wont be done for years.
Le Mans Master
Joined: Jan 2006
Posts: 6,506
Likes: 139
From: Butler Pa
Why not an 8000 rpm 350? Won't be any harder to build than a 327, and it'll make a little more torque.
I have an LT-1 that I used to shift at 7800 rpm. It just took a different cam, intake, carb and good exhaust. The rest are stock LT-1components.
I have an LT-1 that I used to shift at 7800 rpm. It just took a different cam, intake, carb and good exhaust. The rest are stock LT-1components.
Safety Car
Joined: Feb 2006
Posts: 4,367
Likes: 59
From: FL
Originally Posted by bashcraft
I wouldn't use a small journal motor.
Actually, building an 8000 rpm motor gets harder with each stroke increase 327 - 3.25, 350 - 3.48, 383 - 3.75. You want to do it easy, use a 302 - 3.00.
Also, the larger the displacement, the more air you have to pass, so an 8000 rpm 350 is passing a lot more air and gas than an 8000 rpm 302. So your heads need more work, bigger valves, and so on.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Try 400" destroked to a 350"?
Years ago a mag article did a build on a 400" block with a 327" crank to make a 350". Used the large journal 327 crank though with Ford 6 cyl rods 6.25" long to make it work. U need the large journal 327" crank to make brg spaces out of 400" brgs fit - small journal spacers not availible.
Extremlly flat and broad torque curve. Smooth idle and great high end too. Burned 83 octane with over 10.5 c.r. (long dwell time at TDC & BDC) and the moderate displacement with hi c.r. would make decent mpg.
The article called it the 350" mtr Chevy should have built.
I think it was Larry's mailorder parts house here in the LA basin that built it but i called them once for machine work and they admitted they sent all they're block work out.:o
FYI cardo0
Extremlly flat and broad torque curve. Smooth idle and great high end too. Burned 83 octane with over 10.5 c.r. (long dwell time at TDC & BDC) and the moderate displacement with hi c.r. would make decent mpg.
The article called it the 350" mtr Chevy should have built. I think it was Larry's mailorder parts house here in the LA basin that built it but i called them once for machine work and they admitted they sent all they're block work out.:o
FYI cardo0
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
BTW don't forget those old blocks had plenty of metal in them for overbore. .060" over pistons are still availble for the 327" and .080" pistons for the 350". Sonic testing is cheap.
So a 327" with .060" over is = 336" and a 350" over .060" = 360". And just for the curious a .080" over 350" is now = 364".
:o Couldn't sleep tonight.
cardo0
So a 327" with .060" over is = 336" and a 350" over .060" = 360". And just for the curious a .080" over 350" is now = 364".
:o Couldn't sleep tonight.
cardo0
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Le Mans Master
Joined: Mar 2004
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From: Little Rock AR
Originally Posted by Mark_Milner
I would. It is easier (less mass) to get spinning to 8000 rpm. the rods are the weak link in the small journal engines. Use some good aftermarket rods and you are set.
Actually, building an 8000 rpm motor gets harder with each stroke increase 327 - 3.25, 350 - 3.48, 383 - 3.75. You want to do it easy, use a 302 - 3.00.
Also, the larger the displacement, the more air you have to pass, so an 8000 rpm 350 is passing a lot more air and gas than an 8000 rpm 302. So your heads need more work, bigger valves, and so on.
Actually, building an 8000 rpm motor gets harder with each stroke increase 327 - 3.25, 350 - 3.48, 383 - 3.75. You want to do it easy, use a 302 - 3.00.
Also, the larger the displacement, the more air you have to pass, so an 8000 rpm 350 is passing a lot more air and gas than an 8000 rpm 302. So your heads need more work, bigger valves, and so on.
The 327 will stand up to more RPM where a 350 is more likely to fail. I drive a 302 hard and have no fear of 7500 RPM when ever I want. Probably can go higher but this one would be difficult to replace if it went bang. Steel crank, better rods, forged pistons and a stout valvetrain are required to do this if you want to sleep well at night IMHO. The 327 gives you a little bit more torque but still allows regular wicked RPM. A 383 is more fun just driving around but if you want to drive it like you hate it, the 302-327 is a blast. Where is DEP?
-Mark.
Race Director
Joined: Dec 1999
Posts: 16,945
Likes: 9
Originally Posted by Mark_Milner
I would. It is easier (less mass) to get spinning to 8000 rpm. the rods are the weak link in the small journal engines. Use some good aftermarket rods and you are set.
Actually, building an 8000 rpm motor gets harder with each stroke increase 327 - 3.25, 350 - 3.48, 383 - 3.75. You want to do it easy, use a 302 - 3.00.
Also, the larger the displacement, the more air you have to pass, so an 8000 rpm 350 is passing a lot more air and gas than an 8000 rpm 302. So your heads need more work, bigger valves, and so on.
Actually, building an 8000 rpm motor gets harder with each stroke increase 327 - 3.25, 350 - 3.48, 383 - 3.75. You want to do it easy, use a 302 - 3.00.
Also, the larger the displacement, the more air you have to pass, so an 8000 rpm 350 is passing a lot more air and gas than an 8000 rpm 302. So your heads need more work, bigger valves, and so on.
there are more benefits to a small journal motor, especially for high rpms..the radial bearing speed is lower than w/ a large journal crank. The only negative result is less journal overlap. A good quality crank should easily remedy that issue.
The cup cars usually use a honda sized 1.88 rod journal...and that's not just for giggles.