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Quote:

Originally Posted by SB (Post 4802564)

I’ve run into many that aren’t wear they should be.

Even pre internet was common knowledge to degree in cans. I would say most that are iff, are retarded. OE’s loved cams in retarded * positions. Smoother idle and emissions I guess.

Most off the shelf petformance cams are ground 4* advanced for a reason.

Cool. So I guess that's really the answer I've been looking for. I'm going to throw a stock timing set in from one of my other blocks for SnGs and to double check it against my a/m one. If it's retarded like I think it'll be, I'll put my a/m set back in at 8° advance which is really 6° or 7° and check it.
Thanks again for everyone's input.

OP. taking about advance and retarding cams, you may believe the below quote of myself is interesting. Take a look at the flat tappets:

Quote:

Originally Posted by SB (Post 1865336)

Go to Bam's site www.mercruiserparts.com , go to engine look up tables, find your engine and it's camshaft part # and then look below. Disclaimer: these are my notes from other sources and being human I am wrong sometimes.

Mag BBC 454/502 Flat Tappet (rect heads)

.004” 296*, 296*
.006” 286*, 286*
.050” 224*, 224*
.200” 130*, 130*
Valve lift with 1.7 .510”, .510”
LSA 115.5
Merc Part#431-9830 / GM#14096209
ICL 114 ATDC
ECL 117 BTDC
GM Part#10185060 (same as above but ground with 5 degrees advance)
ICL 109 ATDC
ECL 122 BTDC

======================================

Merc Mag Roller
Merc# 431-850478 / GM#12551622
.004 300*/ 300*
.006 288*/288*
.050” 225*/225*
.200” 125*/125*
Lift .483”/. 483”
ICL 109*
LSA 115.5*

Quote:

Originally Posted by SB (Post 4802574)

OP. taking about advance and retarding cams, you may believe the below quote of myself is interesting. Take a look at the flat tappets:

edit: I was wrong. Close, but different. They did use the same cam as the one before and just advanced it though. Is that what you were pointing out?

If I recall, you are putting together an L29, correct?
If they are factory GM L29 valvesprings, please do:
1) measure the installed height of the spring (telescoping gauge between the retainer and the spring seat.
2) take a few springs to somebody with a spring checker and find out the spring pressure AT THAT COMPRESSED HEIGHT.
3) smash it another .490" and take note of the pressure AT THAT HEIGHT as well.

L29's came in trucks with straight springs and later conical or beehive springs, neither of which are considered performance springs.

I would want to see 90 lbs on the seat (usually at 1.88" ht) and over 300 lbs at max lift.

Quote:

Originally Posted by mcollinstn (Post 4802609)

Right. It's an L29 including the heads which are 297s. When I had the engine machined, I also had the machinist check the springs. They're the ones that came with the cam. They spec'd out well.

Here are the numbers:
145# @ 1.88"
360# @ 1.297"
Coil bind 1.130"

When I built the heads, I measured the valves and used shims to get everything in spec. I set them at 1.88". I also removed the rotators and cut them for posilocks at the same time.
If I were building this for a car, I never would have gone with a used cam and springs. After this whole debacle I'll never use a used cam again though...

https://cimg1.ibsrv.net/gimg/www.off...fc31e3286f.jpg
https://cimg9.ibsrv.net/gimg/www.off...8c4ccb589b.jpg
https://cimg5.ibsrv.net/gimg/www.off...5d39aa414d.jpg
https://cimg3.ibsrv.net/gimg/www.off...a77f485ec7.jpg

What’s wrong with the used cam ?

Quote:

Originally Posted by SB (Post 4802614)

What’s wrong with the used cam ?

Nothing physically. It's just been all the problems I had with not having a cam card. Now that I know all the specs for a 1622, it wouldn't bother me to use a good one of those again.

If you bought that cam new, it would not have come with a cam card; t's OEM. The cam is within the OEM tolerances. You're so deep in trying to figure out a detail that doesn't really matter for what you're doing, that you're missing the forest for the trees at this point.

You've made this much more complicated than it needs to be. And there is nothing wrong with that cam.

Quote:

Originally Posted by TomZ (Post 4802619)

I wouldn't have bought a factory cam new. I don't understand how you think these details aren't important. If I had thrown it in dot to dot and been done with it I'd be 6-7 degrees retarded. How is that ok? Seriously. If I'm in error tell me. I told you from the minute I started screwing with it that I didn't think there was anything wrong with your cam. Don't think for a minute I think there is.
What's made this difficult is me doing something wrong and trying to learn from it. From this **** up I've learned a ton more that I thought I already knew.

Here’s my 2 reasons for telling you to put it in 109-111 icl.

#1: you have been using a degree wheel kit and are using a multi keyway timing set. So why wouldn’t you install it for better midrange power even if not a set world on fire difference? But there will be a difference.

#2: see #1

What movie was this ? “The resistance runs strong.”

I agree. This whole thing has been painful.

Lololololol Oh well.