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Discussion Starter · #1 ·
Sorry this post is a bit long but I'm going to try to provide all the information I can ahead of time. Probably too much info - I tend to ramble.

A good friend of mine owns a '72 C-10 Chevy 4x4. About eight years ago he had the 350 SB in the pickup rebuilt. The builder had the block bored and stated "It's somewhere around 400 C.I. now". The builder also installed a "mild" rec cam and a stock GM HEI dizzy.

In keeping with the sketchy "... somewhere around 400 ..." information, I have been unable to obtain detailed information on this engine. (Owner had fallout with builder)

My involvement began last Fall when my friend complained that the engine lacked power and he had taken the Quadrajet carb to a friend for a rebuild. I suggested that after the carb was reinstalled we should, at the minimum, install new plugs and check the timing.

Four months later my friend finally got the carb back. It was totally screwed so off to a "real" shop for another rebuild it went. (Couldn't convince my friend we could rebuild it in a couple of hours) Two days later we reinstalled the carb, installed new plugs, hooked up my timing light, and to my disbelief, timing was at 50 degrees at 550 rpm (no vac advance). The dizzy is a non ECM with centrifugal and vacuum advance.

After a bit of research, I informed my friend "If all you were going to do was trailer this pickup to a track and race it, we have no problem". But this is not the case. The pickup is (was) a hard working farm truck. My recommendation was to pull the dizzy, set the correct initial timing. and get this pickup running for the street. His reply was "Aw, it's running, I don't want to pull the dizzy".

So now forward ahead another four months to about two weeks ago. I am informed of another ongoing "deal" with this engine. It has had a "hot start" problem for a few years and was chewing up starters. Didn't bother my friend (lifetime guarantee on the starters) but when it got to a new starter every two weeks, he decided to do something about it. Someone told him the timing was causing "kickback" which was tearing up the starters. My opinion is that a remote solenoid kit will fix the starter problems.

Be that as it may, at least now he is willing to pull the dizzy. Good, he waits until it's 100 degrees every day. His shop is an uninsulated steel building with temps approaching 115-120 inside and we can only work on the engine for 2-3 hours every afternoon (it's irrigation season and crop water takes priority over pickup). If the pickup ran on sweat he would never have to run to town for fuel again! To top that off, working on the engine in a 4x4 is a real pain.

So here (finally) is the problem:

1. Set TDC on compression stroke.
2. Marked #1 on dizzy base.
3. Pulled dizzy cap - rotor attaching screws are missing. found them in dizzy base. With rotor in position it is pointing at #4 rather than #1.
4. Checked timing mark on damper. Way off! About 3 inches counter clockwise from O degrees TDC. OK, maybe it slipped.
5. Pull dizzy. Reinstall with rotor pointing at #1. Snug dizzy clamp and install cap.
6. Will it start? NO! Will not even attempt to fire. Advance and retard dizzy in small increments, still will not fire.
7. Check electrical connections and spark - OK. Check for fuel - OK.
8. Tell friend next step is to 1: remove valve cover to be absolutely certain we are on compression stroke and 2: remove bumper, grill, radiator, water pump, etc. so we can pull timing cover to check and reset cam timing (if necessary).
8. Friend tells me "Let's put it back the way it was".

OK, in this heat I am a whipped puppy and willing to put it back the way it was and let him deal with it. But I don't want to. I"m too old, fat, and set in my ways to let anything mechanical defeat me.

Is there any way to get this engine running without putting it back the way it was and without pulling the timing cover?

Thanks,

Mike
 

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First off if the builder did a .060 overbore the new cubic inches is 361.
Next is I doubt it jumped timing on the chain. Second is was the mechanical advance checked to be assured it wasn't stuck at full advance? This is common for HEI's with high miles to do. If it's stuck open it's very difficult to set the timing correctly. Pull the cap and assure the mechanical advance operates smoothly with no sticking points. Next is go to the parts store and get a replacement harmonic balancer for it. The balancer on it likely slipped a long time ago. There's no need to remove the water pump and timing cover.
Once you get the new balancer installed go from there and try again.
 

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Discussion Starter · #3 ·
Thanks for the quick reply and info.

First off if the builder did a .060 overbore the new cubic inches is 361.

Next is I doubt it jumped timing on the chain. Second is was the mechanical advance checked to be assured it wasn't stuck at full advance?
Yes. Before installing the distributor. Snaps back with no apparent restriction. Moves freely. But will double check to be certain. My friend "tested" it. I'll do it myself this time. I'll also double check fuel flow, he did that also.

New harmonic balancer shouldn't be a problem. I'll just tell my friend he can take it back if turns out the old one is "good". To be kind, I will call him "frugal".

Should add that we did not set timing mark to TDC. Since mark was way off, I left it where it was after finding TDC on compression stroke, then set rotor to #1. Should I have set timing mark to TDC and then set rotor to #1?

New info: I forgot to add in original post that friend told me builder had trouble starting engine after rebuild. Two or three other people looked at it and got it running after "messing" with it for awhile. Friend says they reset timing to get engine to run.

I suspect timing chain did not slip but was installed incorrectly in the first place. I hope I'm wrong!

My friend will be off to his nieces' wedding for the next three days so I won't have any new info for several days. Could possibly be as long as two weeks.

Thanks again,

Mike
 

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;)
Thanks for the quick reply and info.



Yes. Before installing the distributor. Snaps back with no apparent restriction. Moves freely. But will double check to be certain. My friend "tested" it. I'll do it myself this time. I'll also double check fuel flow, he did that also.

New harmonic balancer shouldn't be a problem. I'll just tell my friend he can take it back if turns out the old one is "good". To be kind, I will call him "frugal".

Should add that we did not set timing mark to TDC. Since mark was way off, I left it where it was after finding TDC on compression stroke, then set rotor to #1. Should I have set timing mark to TDC and then set rotor to #1?

New info: I forgot to add in original post that friend told me builder had trouble starting engine after rebuild. Two or three other people looked at it and got it running after "messing" with it for awhile. Friend says they reset timing to get engine to run.

I suspect timing chain did not slip but was installed incorrectly in the first place. I hope I'm wrong!

My friend will be off to his nieces' wedding for the next three days so I won't have any new info for several days. Could possibly be as long as two weeks.

Thanks again,

Mike
"Should I have set timing mark to TDC and then set rotor to #1?" In a word, yes. Or set the timing mark to the amount of advance you wanted to start the engine with- like 14 degrees BTDC, for example. If you set the timing mark to TDC and the rotor to #1 terminal you would have 0 degrees BTDC, or TDC in other words. Most engines want more timing than that0- although it may start there just fine. But by setting it "where ever it was", the initial timing was off. But still, as long as the engine started you should have been able to set the timing where you wanted it unless the distributor vacuum advance was hitting the intake or firewall. More on that below.

Here is a page on how to set the distributor in it where it will start.

Set the initial timing (vacuum can disconnected, hose from carb plugged) to about 14 degrees BTDC. If the vacuum can hits the intake or firewall, the distributor needs to be removed and reset so you can time it. Reconnect vacuum advance after you are done timing it. You may find it works better using full time (manifold) vacuum for the advance. If you were using ported vacuum before, the idle speed will increase using manifold vacuum- IF the vacuum advance can is good.

Info on timing can be found here.

Info on the timing marks and timing tabs is here, including how to check for the damper outer ring being loose.

Also, if the total timing was checked w/the vacuum advance connected, the timing could be as high as 50 degrees BTDC. But the way to check the total timing is w/the vacuum advance disconnected and plugged. Raise the engine speed until the timing mark quits advancing and that reading is the total timing. It should be around 36 degrees.

For you to see 50 degrees BTDC at 550 rpm is WAY too much! So much so that severe detonation (and engine damage) will almost certainly be the result if left that way. Are you positive the timing light was on plug wire #1? And that the dial back timing light was read correctly? Not saying you don't know your tools, but something is wrong. If you want, you can make a temporary timing tape to double check, because if the timing was really 50 BTDC at idle, the engine should have pinged like marbles in a coffee can being shaken as soon as the engine was put under a load.

The problem that's often seen w/stock HEI distributors is there is too much mechanical advance added. for the amount of initial timing you would like to run. To fix this requires limiting the amount of mechanical advance. More on that is in the "hotrodding the HEI" page linked to above. Sorry about all the links, but there's no way I could cover that much territory in a post w/o them.

Let us know if you need more/better/different info and how it works out for you.

Good luck.
 

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Discussion Starter · #5 ·
Thanks for the info Cobalt327.

I'll visit the links you provided and let that information soak in while my friend is away for the weekend. Hopefully we'll be able to get back to the pickup next week.

Mike
 
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