Horsepower for 69Z 302 w/#140 cam

[miket1]

Sam, you are correct, I have had all my vacuum advance distributors plugged since 1970 and run only mechanical advance,they run much better, as I said earlier I need to fine tune this a bit more. If it doesn't dial in correctly I have a new MSD mechanical dist. I will install as they are very easy to dial in.
I have considered going the day 2 route w/ headers, no smog, etc.,really don't want that look, if I lose a few HP. because of restrictive exh. that's ok, I only drive my Z 50 miles a year.
The heat riser looks to be one of the most restrictive parts so I may try removing that.

[L78steve]

The B26 starts at 4"Hg and is all in at 8. Not sure about the B28 never had one to test. If you running at 5 idle the B26 is too stiff.
I don't know of any can that will work that low.

[Lynn]

That sounds right on Steve for the B26. I know I remembered 8 for something, and I am betting it was all in by then.

Yeah, Mike, if you aren't going with headers and gears, you will probably do better without VA, as you described.

One other thing, while the 30 30 sounds great at idle, if you are leaving the manifolds and smog on it, and you DO decide to replace the 140, consider a 178 (70 LT-1). Federal Mogul still makes it and it is available cheap from Rock Auto with lifters. I think the lash is 22 24, so you still get some of that good solid lifter sound. But, I would completely understand wanting to go with the 30 30, if for no other reason, just the sound of those lifters at idle, especially with the manifolds, as you can't hear as much exhaust note at idle, even with the chambered exhaust.

Keep us posted.

[Salvatore]

Stock single point distributor works fine. I ran 11.50's (LT-1 motor) in the old days with a Chevy distributor recurved. No issues at 7,500 rpm's.

[miket1]

Thanks Lynn, and everyone for the opinions,
Yes the chambered is a little louder, what are the specs on the 178, I wanted to stay away from the .030/.030 because the lifter were too noisy to suit me, I had them set at .026/.026, still noisy, so I decided to try the 140.
one thing I noticed with this 140 cam, my automatic choke works great,,but even at cold startup this cam wants air before the choke is warmed up to open, I am going to adjust the choke so it isn't closed so tight.

[Salvatore]

How does the 140 cam effect lifter noise compared to the 30-30? Just wondering.

[Lynn]

The 178 has a little less duration. I think the lash is 22 24 so it is a bit quieter than the 30 30. I have a 178 in my 69 L46 motor that is in my car now, and most guys have to ask if it is solid lifter.

I think the 140 recommended lash is 24 24, but can check this evening and say for certain.

I have the specs for the 178 (according to GM) in the Chevy Power book and can post them tonight. Someone probably has them handy.

[L78steve]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: L78steve</div><div class="ubbcode-body">The B26 starts at 4&quot;Hg and is all in at 8. Not sure about the B28 never had one to test. If you running at 5 idle the B26 is too stiff.
I don't know of any can that will work that low. </div></div>

Correction, The B28 starts at 4 and is all in at 8. Never had a B26 to test.

[Lynn]

Thanks Steve.

I have a buddy coming over soon to set up a distributor on my Sun machine. I will get the MSD out and check that vac can to see: 1. which one it is, and 2. when it starts and finishes.

Would be good to have those figures published.

[ZLP955]

Found a great thread over at CRG with advice on the vacuum can for a 480 dist and recurve specs:
http://www.camaros.org/forum/index.php?topic=4045.0;all