Crate engine swap advise please?

[73 C10]

Try limiting it to 8- 10 and see what that does.

Sent from my LGLS991 using Tapatalk

I will do that next.

Keep in mind that in post 182, I said did not report the problem 'till the end of the trip. I seemed fine when I left, I think.

Also my set up will be

8* base, 20-22* va, 20* mechanical, 98, 95, 7037, 5" springs. Only changing one thing. Base to 8*.

Back in a few...

 

[350runner]

Do this test without vacuum advance

Sent from my LGLS991 using Tapatalk

 

[73 C10]

OK, so I re-read this and maybe you are reading the difference. I don't know what light you are using.

If you are reading the difference, that is too much VA.

The paperwork specs 10* on the cam, which you reminded me is 20* on the crank earlier. I new that and I agreed. That's what I measured. That's why when you suggested the 15* it made sense, and still does. The 2:1 thing. I thought we agreed. I thought we discussed this earlier.

I like to talk in one unit and since base is in crankshaft degrees, staying in crankshaft units makes sense to me. That's why my count ends up in the 50's total.

 

[350runner]

What cam are you running?

Sent from my LGLS991 using Tapatalk

 

[rich weyand]

The paperwork specs 10* on the cam, which you reminded me is 20* on the crank earlier. I new that and I agreed. That's what I measured. That's why when you suggested the 15* it made sense, and still does. The 2:1 thing. I thought we agreed. I thought we discussed this earlier.

I like to talk in one unit and since base is in crankshaft degrees, staying in crankshaft units makes sense to me. That's why my count ends up in the 50's total.

Understood. What I don't understand is whether the light is showing you difference (VA only) or total (VA + base) the way you are using it.

15* on the crank is what you want.

 

[rich weyand]

Understood. What I don't understand is whether the light is showing you difference (VA only) or total (VA + base) the way you are using it.

15* on the crank is what you want.

And with 19" of vacuum, you want the 8" springs.

 

[73 C10]

What cam are you running?

Sent from my LGLS991 using Tapatalk

I don't know that, or the type of piston, or the bore.

 

[73 C10]

And with 19" of vacuum, you want the 8" springs.

I hear ya, but one thing at a time.

 

[rich weyand]

OK, but it's gonna run lean unless you have your foot into it enough for those springs to win against the vacuum and pop up. Running lean is not good. Especially when you are already trying to figure out a knocking problem.

 

[73 C10]

Understood. What I don't understand is whether the light is showing you difference (VA only) or total (VA + base) the way you are using it.

15* on the crank is what you want.

I admit. I may be using and interpreting the light wrong.

 

[73 C10]

OK, but it's gonna run lean unless you have your foot into it enough for those springs to win against the vacuum and pop up. Running lean is not good. Especially when you are already trying to figure out a knocking problem.

Gotcha. I'll do it next.

 

[350runner]

The paperwork specs 10* on the cam, which you reminded me is 20* on the crank earlier. I new that and I agreed. That's what I measured. That's why when you suggested the 15* it made sense, and still does. The 2:1 thing. I thought we agreed. I thought we discussed this earlier.

I like to talk in one unit and since base is in crankshaft degrees, staying in crankshaft units makes sense to me. That's why my count ends up in the 50's total.

What paper work are you speaking of?

Sent from my LGLS991 using Tapatalk

 

[73 C10]

So now. I started by checking what I was at pre-drive. I unplugged the va and pluged the carb port. I zeroed the light. I read the timing on the tab at 10* @ 580 RPM. I adjusted the light 'till the TDC mark on the balancer lined up with the 0* on the tab and I had adjusted the light 12* from zero on the light. 2* difference. So go with what you want but there is an offset and I've been stating the light adjustment numbers so far. I set the light to 8 from 12 and set the distributor where the TDC on the balancer lined up with the 0* on the tab. I think that would be 8* BTDC @ 680 RPM. And would read 6* on the tab but I admit , I don't think I stopped to look for comparison.

I took a a spin with the va off and port plugged. It bogged taking off from a more labored sounding idle. Pulling out light footed was OK, but hammer down up to 45 was the rattling valve train sound. It lessens when letting of a bit with the foot.

Almost the same with the va plugged in. Bogged taking off.

 

[350runner]

I bet my last dollar your just experiencing rattling rockers...

Sent from my LGLS991 using Tapatalk

 

[73 C10]

What paper work are you speaking of?

Sent from my LGLS991 using Tapatalk

It came with the new distributor I put in. Summit Blueprint GM

http://www.summitracing.com/parts/SUM-850001R

If you follow the link and look bellow, there is a link to instructions. That is a PDF download that matches the hard copy I speak of that cam with the part.