Rebuilt motor just started and over heats

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witteman

Test & Tuner
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I just got done rebuilding my 340 and it gets hot very fast. I beleive my problem is in the distrbutor drive gear not being set correctly. Forgive me for not being exactly clear here I am just a weekend so called mechanic. On top dead center I have the slots lined up with the the crank but the distributor does not line up with the #1 Piston.

Thanks TOM
 
I thought that when you drop the cam gear in the slot is suppose to point towards the #1 spark plug or intake port on the head? If i remember correctly thats what the HANES manual said to do when i rebuilt mine.
 
If it isn't your distributor another easy thing to check is your thermostat, It might be stuck or faulty, easy way to see is put it in a pot of water and heat it up and see if it opens. good luck
 
really it doesn't matter where that gear slot points. you can just put the plug wires on the cap to line up where it needs to be in the new location. fron the factory a small block slot pointed to the left front intake bolt.
 
abodyjoe said:
really it doesn't matter where that gear slot points. you can just put the plug wires on the cap to line up where it needs to be in the new location. fron the factory a small block slot pointed to the left front intake bolt.
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Exactly, it is all relative. The thermostat is a good point.

I am curious how tight the motor is?
 
When the distributer gear is dropped in, it goes past the gear on the cam which rotates the distributer gear about two gear teeth's worth. If you lined it up when you dropped it in, then it is off. Either re-align the distributer gear by removing it and putting it in properly, or, and I am not sure if it is even possible, rotate the distributer a bunch to compensate. Out of time may run, but will run hot!
 
Either re-align the distributer gear by removing it and putting it in properly, or, and I am not sure if it is even possible, rotate the distributer a bunch to compensate. Out of time may run, but will run hot!
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doesn't need to be out of time. if the gear is in the wrong position , all it does is move where #1 is on the cap. no need to be turning the dist around in all different positions. it really doesn't matter where the slot points as long as the plug wires are on the cap right. put the motor at TDC on #1 cyl. then put #1 plug wire where ever the rotor is pointing. simple.
 
as said..does not matter where the intermediate shaft is pointing as long as the cap and rotor are align for no 1....

make sure the timing is set correctly
 
you could have air pockets in the block however a fresh engine will run extremely hot when first fired / i drill a 1/8 inch hole in the outer area of the thermostats on my engines before firing them for the first time it does not affect the thermostat from proper operation but lets the water fill the block / i also run the engine with a garden hose in the filler neck of the radiator with the drain valve open while the cam breaks in / let the engine cool then fill with coolant and you should be fine!
 
Funny I started up my 340 for the first time Sunday afternoon. The temp outside was 90 degrees. I used straight water and NO T-stat. Timing was set at 35 degrees and I let it rip @ 2,500-3,000 rpms for 20 mins. I was spraying the rad down with a garden hose. Temp never got above 175.

Drove it today for 10 miles. Still no T-Stat in it. Motor warmed up pretty quick. Maybe 2-3 mins longer than with a T-Stat. I found in the past you really do not need a T-Stat in the summer time. Motor seems to run around 170 degrees--perfect, imo.
 
I can' t thank you guys enough! What A great site this truly is. In a couple hours I will be working on the motor and will let you know how it all works out wednesday.

Again Thanks Alot!
 
HemiEd you were right on. The motor seized up. I beleive it is the main bearing AGAIN! Oh well little bummed out right now. Back to the drawing board!
 
sixpakmopar said:
you could have air pockets in the block however a fresh engine will run extremely hot when first fired / i drill a 1/8 inch hole in the outer area of the thermostats on my engines before firing them for the first time it does not affect the thermostat from proper operation but lets the water fill the block / i also run the engine with a garden hose in the filler neck of the radiator with the drain valve open while the cam breaks in / let the engine cool then fill with coolant and you should be fine!
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Happened to me so I drilled three 1/8" holes in thermostat. The great thing about having the holes is you can fill the cooling system to full capacity before even firing the engine. That way the fresh engine is completely full of coolant when first fired. With the three holes the car still warms up plenty fast in the cold weather so there is no draw back.
 
witteman said:
HemiEd you were right on. The motor seized up. I beleive it is the main bearing AGAIN! Oh well little bummed out right now. Back to the drawing board!
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Well this is one time I wish I wasn't right, so sorry to hear this.

Did you "plasti-gauge" the bearings when you put them in?
 
man that sucks :( Sorry to hear about that. I remember when we (brother and I) rebuilt an AMC inline 6 4.2l engine and the head gasket blew on the first start up. Talk about a total mood killer :(
 
I'm sure glad my little 340 came out ok. I've been in a fowl mood the last few weeks thinking how for $2,500 I could had gotten a "worn out" used car, which still runs alright. Heck my 18 year old rusted out car that I been running around town on, renting engine hoists, etc isn't worth $1,000 yet it takes me where I want to go and gets 20+ mpg.

I've been like why-why-why did I start this project in the first place? How stupid it is to be able to burn up the most fuel in the quickest amount of time.

But this last week I am driving around now with the 340, passing traffic with ease.

Sure once I decide the motor is broken in enough to open up the front 4bbl carb, I be hook on speed once again, lol

Motor (Small).jpg
 
dodge freak said:
Sure once I decide the motor is broken in enough to open up the front 4bbl carb, I be hook on speed once again, lol
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haha. When I put my 360 in my 1988 Jeep Wrangler, I broke the cam in at 12:00 midnight, then loaded it up onto the trailer and hauled it off to Silver Lake Sand Dunes in MI to take it off-road. Drove it around town and put about 10miles on it, then wide open, 5500 RPM up the sand hills.
 
dodge freak said:
I'm sure glad my little 340 came out ok. I've been in a fowl mood the last few weeks thinking how for $2,500 I could had gotten a "worn out" used car, which still runs alright. Heck my 18 year old rusted out car that I been running around town on, renting engine hoists, etc isn't worth $1,000 yet it takes me where I want to go and gets 20+ mpg.

I've been like why-why-why did I start this project in the first place? How stupid it is to be able to burn up the most fuel in the quickest amount of time.

But this last week I am driving around now with the 340, passing traffic with ease.

Sure once I decide the motor is broken in enough to open up the front 4bbl carb, I be hook on speed once again, lol
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That engine in the picture looks like it has 80k miles on it.
 
Mad Dart said:
That engine in the picture looks like it has 80k miles on it.
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It does! It does!

That is how it used to be. No pictures of how it is now. Pretty much the same expect its cleaner.

Heck I was hitting 6,800 rpms with my old motor. I wasn't too happy going with kb hyper pistons. I wanted forged for those 7,500 rpms runs but shop guy claimed motor needed to go .040 over and like nobody sells forged .040 over pistons--at least for $500.

I'm not sure how high I be revving this, 6,000 for sure but it would be best to limit it at that
 
Badart said:
Is that wood on the firewall?
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Yeah, cause I change things around over the years. This way I just drill two holes in the firewall to mount the wood and I can drill all the holes I want in the wood to mount coils, ignition boxes, etc. Really I can just use wood screws to mount stuff with no drilling. Makes life easier for me. I really could care less how Mopar used to do things. This is my car and is done my way now, lol.

I got a wood battery tray also. All my amps in the trunk are mounted on wood too. Wood is easy to work with and you can just remove it later on and not have lots of holes everywhere.

If I wasn't so lazy I would stain the wood. Wood used to be used even for car frames. Yeah that is going too far, ha ha. But it used to work I guess.
 
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