Aluminum 409 Build

jim_ss409

Well Known Member
Supporting Member 5
Amazing!!! This is still with under 12:1 compression correct??

It's got about 12.1 to 1 compression now.
We originally had about 11.5 but when we had the engine apart, we used the pistons that were supposed to be used in another iron engine we were building.
The new pistons had shallower valve reliefs and should have given us closer to 13 to 1 but it turned out that the intake valve relief was in the wrong place so we had to make it wider and lost some compression. :scratch I'm guessing they used the Z-11 intake valve positioning when they made those pistons. (the intake valve is moved over .190 on Z-11 heads)
 

BSL409

Well Known Member
Supporting Member 6
Jim & Jim
Any updates on this and the 55 we have not herd much from you guys lately :scratch
 

jim_ss409

Well Known Member
Supporting Member 5
Jim & Jim
Any updates on this and the 55 we have not herd much from you guys lately :scratch

We haven't been out much this year at all.
The 55 Chevy has a new engine and it's running great but we still haven't got the Pontiac back up and running since we blew a head gasket last fall.
I'll probably find some time and get it running sometime in September. :beer

We built an iron 481 ci engine for the 55 Chevy. It's a 656 passenger car block with about 13 to 1 compression. The heads are ported Edelbrocks from the stroked 348 that we got from Joe Sherman.
We went a little mild on the cam to keep the car in the low ten second range. (it has a roll bar instead of a full cage so it's only legal for 9.99 or slower) Right now it's running 10.06 to 10.10 in the heat of summer.
The cam is... 263/274 @.050 with a relatively wide 112 degree LSA. We also went with relatively mild lobes in order to prolong the valve train life. The gross lift is .757 int. and .693 exhaust.
 

Ronnie Russell

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Supporting Member 2
A well thought out engine, for sure. Looking forward to seeing the both of you show up with healthy cars. :):)
 

dm62409

Well Known Member
Supporting Member 12
We went a little mild on the cam to keep the car in the low ten second range. (it has a roll bar instead of a full cage so it's only legal for 9.99 or slower) Right now it's running 10.06 to 10.10 in the heat of summer.
The cam is... 263/274 @.050 with a relatively wide 112 degree LSA. We also went with relatively mild lobes in order to prolong the valve train life. The gross lift is .757 int. and .693 exhaust.[/QUOTE]. Jim_ss409

It doesn't seem that long ago, a cam like that would be considered huge.
 

jim_ss409

Well Known Member
Supporting Member 5
It doesn't seem that long ago, a cam like that would be considered huge.

Yeah for sure, and .600 lift used to seem like a lot.
I already had a cam that would probably have made more power. It's a 266/276 on a 108 LSA plus it has more lift, but it would have required deeper valve relief notches in the pistons.
We figured we could get into the 10.00 range with a little less cam. I'm actually pretty happy with how smooth the idle is with this 112 LSA cam. (smooth for a race engine)

The cam in the aluminum engine is pretty big,,, 282/292 @.050
I've also got one that's just a bit smaller,,, 276/286 @.050 I'd like to try the smaller cam, but I'm pretty sure we'll end up putting the bigger one back in. :D
 

61 Bubble

Well Known Member
Damn Jim, I would STILL call that a big cam @ 757 lift and 263/274.

We just dyno'ed my lil Zl-1 and my cams a baby compared to those! It's only 715 lift 258/263. the little aluminum guy responded with high 700Hp figures so far. Few more changes and hoping to break the 800 mark. Hoping to get with 20Hp of your aluminum motor HP wise with this dinky cam.
 
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