#21  
Old 10-14-2019, 10:30 AM
Cliff R's Avatar
Cliff R Cliff R is online now
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I just had a new aftermarket HEI in here last week.

At a glance it looked like a nice unit, especially the housing, very well made and had almost a "billet" look to it. As I got into the job I started finding a few issues. The center cam and weights appeared to be exact copies of factory stuff, and hardened, but they didn't have the correct orientation and "flats" to stop the advance curve. It just kept advancing past where a factory unit would have stopped mostly because of the relationship of the parts and "low" tension of the springs. Welding in a positive stop cured that issue.

The VA was adjustable for how much it added vs the spring tension, good deal there and it had a relatively light spring in it, starting around 5" and all in around 10" vacuum so it was a decent candidate for the got-to-have MVA at idle guys and none of it dropping out if your engine makes at least 10" vacuum in and out of gear..

The main shaft was "soft" and I could easily scratch it with my pocket knife. Even worse they machined the oil pump drive "slot" so far up it intersected the hole drilled for the roll pin making it pretty "weak" in that area.

The gear looked pretty good, not that dark black imported material we typically see used for them. It was some sort of cast material, dark gray in color and reasonably hard although there is no real way that I know of to gauge the durability of a cast part without putting it in service and see if it is compatible with the cam and hard enough it doesn't wear out, and not so hard that it wears out the gear on the cam. It was set up super-tight for end play with one very thin shim on it.

The electronic parts looked totally "generic" and no marks on them anyplace.

The retainer for the pick-up came off when I pulled the shaft so someone forgot to seat it fully into the groove.

It use oil for lubricant on ALL of the parts instead of grease, so not sure how well that would have worked in the long haul?

I'm still all-in for using factory Pontiac HEI's vs any of this "off-shore" stuff. Problem is that it is becoming a bit difficult to find good cores. At least 50 percent at this point will have a worn lower bushing and scored/worn shaft at that area. Nearly that many will have worn weight holes and the pins often worn nearly in half.

My stock is running extremely low and probably a good thing I don't do a lot of them these days and don't really want to.

In contrast the points distributors I have or get in are almost always in decent shape and rebuildable. They require a new advance sleeve (I use a stainless steel one) as the rubber one is long gone, and the parts are usually rusty enough we have to zinc plate them. Otherwise not much is needed beyond a good cleaning and checking/setting up the advance curve for where it is headed.......Cliff
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73 Ventura, 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile)
  #22  
Old 10-14-2019, 11:52 AM
"QUICK-SILVER" "QUICK-SILVER" is offline
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Quote:
Originally Posted by many birds View Post
Interestingly, putting it on with the summit weights, retarded the initial timing to 0 degrees.
Changing weights and centers shouldn't change park position. Your Pertronix weight picture shows the tip of the flats on the outside of the weights. If a tip is touching that would keep it from returning to park position. In other words it would use up part of the advance.

pic of yours and then a pic I've got of a factory HEI and a china HEI. Note the flat side tips are on the inside of the weights in park.





Oddly enough these china weights work slick as can be. Trying to measure by hand it appears they'll go right at 12į max at the distributor. That's with full weight sling and weights hitting the stop in the rotor button. Didn't look to see if the slot was bottoming out.

Clay
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  #23  
Old 10-14-2019, 03:14 PM
Sun Tuned Sun Tuned is offline
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Clay,
Good eye. But that's the way moroso/mrgasket designed their "stuff".
More On the operation of this junk later tonight.

Back later.
  #24  
Old 10-14-2019, 04:06 PM
many birds many birds is offline
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Tried monkeying with it again this morning. Bottom line, no luck.

I bumped the base timing to 17 degrees. Reset the idle and mixture screws. Idled ok, about 12 inches of vacuum and 9 in drive. Excellent throttle response off the line, but mild pinging on moderate throttle (top of the primaries, not into the secondaries on the q-jet). Hot starts were ok, no worse than before, but I donít want any pinging.

I have backed it off to 13 degrees now. It really likes something closer to about 10 degrees at idle, but that makes it sluggish everywhere.
  #25  
Old 10-14-2019, 07:16 PM
Sun Tuned Sun Tuned is offline
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Those advance parts are what is commonly known by folks that have been around since say 1978 or so, as a moroso curve kit. I don't have a hair of a notion who came up with it first, but suffice it to say mrGasket, moroso, and a couple others have used that same kit for years. Now as I've always known them
The Moroso version was always black oxided, and the gasket version was flask chrome plated.

I've dinked around with the stuff before and managed to get them to somewhat work ok, but you gotta spend a pretty good bunch of time with em and a distributor machine is almost assuredly a must. If not, after about an hour you'll be looking for something sharp to stick in your eye to make you forget about the pain experienced fooling with the damn thing for the last two hours.

Somewhere along the way somebody changed these kits up a bit. Used to be they were really bad about the tail tip of one weight getting stuck by the large end of the other weight thereby creating a lock situation. I guess 10 years or so ago I noticed they had started making the tails just a skosh bit shorter to alleviate this problem.

I can't remember because it's been a long while since I looked at some, but I think your center cam
Is on upside down. Which is why the weights look funny parked the way they are. Again it's been too long and I'd have to put my hand on it.

There never were any decent instructions for the orientation of the cam anyhow, and 80% of the ones installed were not right to begin with.

Was a decent idea I guess but for 5.00 for the kit what do u expect.


Best bet, acquire a decent pair of weights and center cam.
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