It's finally a driver!!! Some general advice please.

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PhillH

PhillH

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So the day finally came when I could take the 360 Scamp out for it's maiden voyage, first engine I've ever rebuilt, very happy!
I already had it initially broke in but not driven except around the block a few times to test driveline. Everything went really well but I just want some advice from veterans. I rebuilt the Edelbrock 625 and have not tuned it yet, but followed directions.
1. The timing is at about 16/17 idle with vacuum plugged, but seems to go almost 50 degrees around 2500 rpms, this seems high to me. Also it runs great with no stalling or hard to turn over but I have to hold the throttle to the floor and crank about 4 or 5 seconds before it starts.
2. Doesn't seem to run hot but when I shut it off the radiator cap is relieving pressure out the vent hose, not to the point of overheating, maybe bad cap or just because the engine isn't all the way broke in, timing???
 
What distributor are you running? Is that 50 degree reading still with vacuum plugged? Are you running a thick insulator gasket under the carb or the thin one? The long crank is likely from either fuel boiling over or excessive fuel pressure. The heat cross over in the intake manifold may also need to be restricted or blocked.
 
Sorry I meant to include it's the stock ignition single point, the carb gasket has a thin one, a thin metal adapter and another thin gasket to run the Edelbrock carb with the Edelbrock Performer intake, square to the other style. Carb is 625. Stock fuel pump.
 
If you have a stock factory distributor you can not run that much initial advance. You need to either re-curve the distributor buy welding up the advance slots, or buy an FBO limiter plate kit, or else buy an aftermarket performance distributor with selectable, limited advance. YOU WILL hurt the engine with that much mechanical, which is typically 32-48, total.

FBO limiter:

http://www.4secondsflat.com/Mopar Mechanical timing limiter plate.htm

So far as the overflow, you may have it over-filled and it may take "a day or two" to equalize. You need to monitor the engine temp with a good instrument, and I do NOT mean the factory gauge, LOL
 
PhillH said:
So the day finally came when I could take the 360 Scamp out for it's maiden voyage, first engine I've ever rebuilt, very happy!
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Congratulations!!!:glasses7:
1. The timing is at about 16/17 idle with vacuum plugged, but seems to go almost 50 degrees around 2500 rpms, this seems high to me.
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If it goes to 50 degrees with the vacuum advanced hooked up, that is correct ballpark.
-> Recheck advance to 2500 or more without vacuum advance. It should be in the mid 30s.

If it goes to 50 degrees with the vacuum not hooked up, that's not ballpark. It will be OK for light throttle, but will ping when the load gets too high, somewhere between 2/3 and full throttle. If it continues or is too severe, the detonation cause a hole in a piston.
-> Recheck your method ( timing tape? tach on correct range, etc). If that is really the number, you'll have to remove the distributor and look inside to see what is up. Before doing that, plot out the advance curve.* It may be useful in figuring out what needs fixin or modification. *(Either write down the rpm for every degree or two it advances, or the timing at every 200 or 250 rpm going up.).

Also it runs great with no stalling or hard to turn over but I have to hold the throttle to the floor and crank about 4 or 5 seconds before it starts.
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Throttle to floor suggests its flooding or too much choke. Check choke, adjust for less. If not choke, look down carb when not running. Any fuel dripping indicates fuel level much too high. If so adjust float.


2. Doesn't seem to run hot but when I shut it off the radiator cap is relieving pressure out the vent hose, not to the point of overheating, maybe bad cap or just because the engine isn't all the way broke in, timing???
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Normal. Temperature of the coolant inside the engine goes up right after engine is shut off. The engine is hot but the coolant is circulating and there is no airflow through the radiator. If there is no overflow tank, it will eventually find its natural fill level as previous poster mentioned. With overflow tank, it will get sucked back in.
 
Will be checking these out thanks.
Mattax, timing was around 30 without vacuum, but I did not pay close enough attention to that, I;ll recheck with better info. I did give about 3/4 throttle for a few seconds to check for pinging, and was happy there was none although it seemed sluggish building rpm's, but I attribute that to not having any tune yet. Also coolant overflow bottle on short list, it did seem the level dropped to about an inch below the filler neck and stayed there. Choke was set at Edelbrock recommendation and still needs tuned so that is a real possibility. Thanks for pointing me in the right direction. I did expect all these things and can't wait to see how it runs after some fine tuning!
 
Pull the plugs right now to get a snapshot of what is going on.....we just pulled ours after cam break-in; front 4 rich, rear 4 OK. Deduced that the secondary throttle stop was set wrong and sho nuff, it was....

1" below the filler neck is normal for a system with no overflow tank. That was the FSM number before overflow tanks were added.
 
Great for the radiator fill level, I won't add more to see if it needs that expansion room, just making sure everything has been burped running the heater and all.. I'm going to do these checks posted here then report back.
 
Fresh engines can make all kinds of creaking and popping noises as well as ticks and occasional clacks.
During the first 200 to 500 miles or so, I try not to restart the engine within a half hour after a normal,warmed up, shut-down. This gives the pistons a chance to cool off, after being heat-soaked.This is more important with hyper-eutectics as they can be installed pretty tight.
 
Update, I do not have to hold the throttle open to start, it will start the same just turning the key. After it's warm just hit the key and stats right up. Pulled the plugs and all looked great except number three, which explained the sluggishness and also the off idle missing that I hadn't even really discovered yet. Bought a new ignition and problem solved. Also the radiator has leveled off and no more pressure escaping the cap, nice! Still need an overflow tank.
 
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