340 with edelbrock heads overheating

[Early a body]

ok update. i overooked on the edelbrock instructions where it says the adjustible stock rockers will hit the sping retainers. Well sure enough I could see where the stock 273 rockers hit the sping retainers.

I tried a differnt carb with no effect what so ever on the idle mixture screws. They do nothing at idle. I guess its possible the valves are being kept slight opened due to the rocker shafts impacting the spring retainers.

the engine struggles at idle to get to 5 hgs of vacuum.

Ill order some adjustable rockers and see how it goes.

 

[RustyRatRod]

ok update. i overooked on the edelbrock instructions where it says the adjustible stock rockers will hit the sping retainers. Well sure enough I could see where the stock 273 rockers hit the sping retainers.

I tried a differnt carb with no effect what so ever on the idle mixture screws. They do nothing at idle. I guess its possible the valves are being kept slight opened due to the rocker shafts impacting the spring retainers.

the engine struggles at idle to get to 5 hgs of vacuum.

Ill order some adjustable rockers and see how it goes.

Do not run it again if the rockers are contacting the spring retainers. Hitting the retainer could possibly unlock a valve and drop it right on top of a piston, cya later tater, game over. You REALLY need to do some studying up on engines. Not trying to insult you, just giving you some good advice. I would not start it again until that problem is fixed.

 

[Early a body]

Do not run it again if the rockers are contacting the spring retainers. Hitting the retainer could possibly unlock a valve and drop it right on top of a piston, cya later tater, game over. You REALLY need to do some studying up on engines. Not trying to insult you, just giving you some good advice. I would not start it again until that problem is fixed.

Thanks Rusty, I think i figured out to not run it again. This may or may not be the problem.

Yeah you did insult me but you also insulted everyone who made comments on this post too. Reason being is I mentioned the 273 rockers on the initial post. No-one mentioned that those could be the problem.

I could have walked away from the post i made with my tail between my legs. But i decided i will update as i go along . Many of the tech issues I have read this past month never had a conclusion. So I am riding this out and will update until the issue is solved in order to save someone else the headache.

you may want to remove that last part of your note as there was really no need for it and it solved nothing.

 

[7e5hangten360]

if you grind a relief on your rockers, you wont have to buy new ones. new rockers would probably touch the retainers too. if you decide on grinding, try to remove the least material possible to make them clear the retainers. also, try to do it rounded so you dont create a stress riser. this rubbing situation needs to be adressed but will not make your engine run hot.

 

[George Jets]

"ok, got it back togeher . same thing is happening."

You mean it is still overheating again?

Guessing they took .006 ths off to straighten the alum. heads, this is raising the compression ratio even more now.

What head gaskets did you use this time around? The recommended Edelbrock .055 ths head gaskets?

☆☆☆☆☆

 

[Rat Bastid]

if you grind a relief on your rockers, you wont have to buy new ones. new rockers would probably touch the retainers too. if you decide on grinding, try to remove the least material possible to make them clear the retainers. also, try to do it rounded so you dont create a stress riser. this rubbing situation needs to be adressed but will not make your engine run hot.

NEVER grind on a rocker. When the geometry is correct they won’t hit.

There is one exception and that is when you get into running springs with an OD bigger than 1.580ish. Then you may have to grind on them a LITTLE.

Grinding on the rocker doesn’t fix the problem.

 

[RustyRatRod]

Thanks Rusty, I think i figured out to not run it again. This may or may not be the problem.

Yeah you did insult me but you also insulted everyone who made comments on this post too. Reason being is I mentioned the 273 rockers on the initial post. No-one mentioned that those could be the problem.

I could have walked away from the post i made with my tail between my legs. But i decided i will update as i go along . Many of the tech issues I have read this past month never had a conclusion. So I am riding this out and will update until the issue is solved in order to save someone else the headache.

you may want to remove that last part of your note as there was really no need for it and it solved nothing.

The rockers are not the problem. Ok, since you don't know when someone's trying to help, cya later tater. Hope the best for you.

 

[George Jets]

After trying everything under the sun, looking like those aluminum heads are just bad castings that have a design problem as they cannot cool properly.

It's been Process of Elimination to get you to this point so far and you still have the same over heat issue. Common denominator > same heads.

440 Source made an aftermarket aluminum big block water pump, passenger side inlet.

It overheated the engines they were installed on because the internal was cast too small and would not allow proper coolant flow.

All that Glitters is not Gold.

☆☆☆☆☆

 

[Rat Bastid]

After trying everything under the sun, looking like those aluminum heads are just bad castings that have a design problem as they cannot cool properly.

It's been Process of Elimination to get you to this point so far and you still have the same over heat issue. Common denominator > same heads.

440 Source made an aftermarket aluminum big block water pump, passenger side inlet.

It overheated the engines they were installed on because the internal was cast too small and would not allow proper coolant flow.

All that Glitters is not Gold.

☆☆☆☆☆

The heads are not why it’s overheating. That would be LAST on the bottom of the list of things that cam make his engine overheat.

 

[George Jets]

@Early a body Quote:

"I decided that i would swap out the X heads to eddelbrock 340 heads.
Installation went fine but now i have developed an overheating problem."

____________________

Factory X Heads are looking pretty good right about now.

☆☆☆☆☆

 

[Rat Bastid]

@Early a body Quote:

"I decided that i would swap out the X heads to eddelbrock 340 heads.
Installation went fine but now i have developed an overheating problem."

____________________

Factory X Heads are looking pretty good right about now.

☆☆☆☆☆

Whatever. You don’t think it’s POSSIBLE something else was changed?? Or something wasn’t changed to accommodate they new heads?

It damn sure ain’t the new heads causing it to overheat. That’s insane.

 

[RustyRatRod]

If you look closely, he said in one post that it overheated with the X heads too. But honestly with his maturity level and unwillingness to take constructive criticism and actually learn, yall are wasting your time here. I'm done trying to help. Let him wallow in his ignorance.

 

[Early a body]

its not my maturity level that is the issue, you really need to look in the mirror,

I never said it was overheating with the x heads.

If you look closely, he said in one post that it overheated with the X heads too. But honestly with his maturity level and unwillingness to take constructive criticism and actually learn, yall are wasting your time here. I'm done trying to help. Let him wallow in his ignorance.

 

[Early a body]

Whatever. You don’t think it’s POSSIBLE something else was changed?? Or something wasn’t changed to accommodate they new heads?

It damn sure ain’t the new heads causing it to overheat. That’s insane.

I agree, the heads are running cooler than the block. I think i found the problem. Funny thing is i did this same swap 12 years ago and used 273 rockers. had zero problems. no longer have the car so edelbrock changed something or i got lucky last time

 

[Early a body]

@Early a body Quote:

"I decided that i would swap out the X heads to eddelbrock 340 heads.
Installation went fine but now i have developed an overheating problem."

____________________

Factory X Heads are looking pretty good right about now.

☆☆☆☆☆

i was about ready to put the old heads back on until i noticed the rockers rubbing

 

[Early a body]

"ok, got it back togeher . same thing is happening."

You mean it is still overheating again?

Guessing they took .006 ths off to straighten the alum. heads, this is raising the compression ratio even more now.

What head gaskets did you use this time around? The recommended Edelbrock .055 ths head gaskets?

☆☆☆☆☆

i am using the edelbrock gasket

 

[Early a body]

if you grind a relief on your rockers, you wont have to buy new ones. new rockers would probably touch the retainers too. if you decide on grinding, try to remove the least material possible to make them clear the retainers. also, try to do it rounded so you dont create a stress riser. this rubbing situation needs to be adressed but will not make your engine run hot.

harland sharp makes a rocker specifically for these heads will be using those first. I think the valves are hanging open a little bit because after checking and checking and finding no vacumne leak its got to be this. I think the added friction is causing it. there is one valve that no matter hoe much i back off the adjuster screw the rocker never gets loose.

 

[Rat Bastid]

harland sharp makes a rocker specifically for these heads will be using those first. I think the valves are hanging open a little bit because after checking and checking and finding no vacumne leak its got to be this. I think the added friction is causing it. there is one valve that no matter hoe much i back off the adjuster screw the rocker never gets loose.

Before I spent one cent on rocker arms I would call Mike at B3 racing engines and talk to him. It’s only a phone call.

 

[MOPAROFFICIAL]

bingo. So interference and pre load is the culprit. Glad you got it nailed down.

harland sharp makes a rocker specifically for these heads will be using those first. I think the valves are hanging open a little bit because after checking and checking and finding no vacumne leak its got to be this. I think the added friction is causing it. there is one valve that no matter hoe much i back off the adjuster screw the rocker never gets loose.