Who races w/OE Magnum short blocks

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Sounds like it’s time for Edelbrocks or EQ’s.
 
Well, that’s the thing with them. They crack between the seats but don’t leak coolant. The crack is only bad because of the possible/probable issue of valve sealing. Coolant comes up next. I’m sure my 275,000 Magnum heads are cracked according to all I read..... but the truck runs just fine!
 
I have 2 sets of magnum heads in my garage that are cracked. 1 set of them came off of my truck that had 350k miles on it. My grandpa bought the truck new and gave it to me in 2007, I daily drove it until 2013. It always ran great without any issues. 2nd set came off of a salvage yard engine my dad bought. The salvage yard had a warranty on the engine and ended up tearing apart several engines to find my dad an uncracked set. My dad will now be buying my EQ heads, so I also have his uncracked heads.

I recommend that you upgrade to the EQ's for performance reasons. But I wouldn't be afraid of using cracked OE heads.
 
Well, that’s the thing with them. They crack between the seats but don’t leak coolant. The crack is only bad because of the possible/probable issue of valve sealing. Coolant comes up next. I’m sure my 275,000 Magnum heads are cracked according to all I read..... but the truck runs just fine!
Where have you found coolant going?
The engine I am in now ran poorly on a few cylinders. Dany and my wife said steam out the exhaust .
We swapped it for Danys "race engine" and I plan on using this one in our 66 cuda.
I pulled it expecting to see one of the cracks opened and a cylinder showing signs of being steamed clean by coolant.
It was more than a gallon or gallon and a half low on coolant when we pulled it so I thought I was on the right track.
Then we found a broken valve spring and bent pushrod and valve.
But all the cylinders were still sooty like no coolant ran thru any of them.
Head gaskets looked fine and no external leaks.
At this point I wonder if it re sooted itself after the coolant got below the water pump as they drove it about 10 miles to the shop??

20181123_140721.jpg
 
Since you quoted me, you must be talking to me.
What makes you think your reply had me find coolant in my cylinder heads?
Where have you found coolant going?
The engine I am in now ran poorly on a few cylinders. Dany and my wife said steam out the exhaust .
We swapped it for Danys "race engine" and I plan on using this one in our 66 cuda.
I pulled it expecting to see one of the cracks opened and a cylinder showing signs of being steamed clean by coolant.
It was more than a gallon or gallon and a half low on coolant when we pulled it so I thought I was on the right track.
Then we found a broken valve spring and bent pushrod and valve.
But all the cylinders were still sooty like no coolant ran thru any of them.
Head gaskets looked fine and no external leaks.
At this point I wonder if it re sooted itself after the coolant got below the water pump as they drove it about 10 miles to the shop??

View attachment 1715253365
 
Since you quoted me, you must be talking to me.
What makes you think your reply had me find coolant in my cylinder heads?
Where you said "coolant comes next".
Your advice (to me and others) has always been valuable and I am just trying to get some insight on my present situation,
Without the hysteria of the internet. We haven't raced a Magnum (yet) but we will if it let's us!!
Didn't mean to hijack your thread.
 
Where you said "coolant comes next".
Your advice (to me and others) has always been valuable and I am just trying to get some insight on my present situation,
Without the hysteria of the internet. We haven't raced a Magnum (yet) but we will if it let's us!!
Didn't mean to hijack your thread.

Hummmm, ummm, retake on the last post....
I often write the way I speak which is a problem because it is missing tone and feeling. With that said, the post I left re read can be taken rudely which is not the intent. Let me try that again!


The crack in the cylinder head is between the valves. It is a thin area and becomes overheated. As far as I know there is no coolant behind that immediate area. The cracking area can effect the valve seat and sealing of the valve.

I have not heard of any heads cracking so bad that they leak coolant but that’s the next step in severity in cylinder heads.

And no worries on thread hyjacking!
No worries at all.
 
My advice would be to get the EQ heads with some good valve springs. They're reasonably cheap, offer a substantial horsepower benefit over stockers, don't crack, and if you pick the right part number you can bolt up LA intakes to them, which are significantly better than the intakes available for magnum engines.

There's no good reason to ever put a stock head back on, especially if you are having some kind of issue with it.


Where you said "coolant comes next".
Your advice (to me and others) has always been valuable and I am just trying to get some insight on my present situation,
Without the hysteria of the internet. We haven't raced a Magnum (yet) but we will if it let's us!!
Didn't mean to hijack your thread.
 
Any ETs with roller rockers or is everyone using stock rockers?
 
Mine are stock.

The ones I had in my Dart were stock as well, right up until I put Harland Sharps on and it made no difference.
 
Mine are stock.

The ones I had in my Dart were stock as well, right up until I put Harland Sharps on and it made no difference.
I also went from stock to Harland Sharpe and saw minimal difference in ET
 
Where the rollers in the tips (valve) or on the stud?
 
There's a roller wheel at the tip, and there are roller bearings in the fulcrum as well. Stock stuff, no rollers anywhere.
 
There's a roller wheel at the tip, and there are roller bearings in the fulcrum as well. Stock stuff, no rollers anywhere.
Yes I know about the stock ones, I have the factory upgrade kit with the 1.7 ratio, new springs and guide plates. Hoping they would allow more hp. Ported the stock heads, back cut the valves. M1 intake racing Q-Jet. I'll see this spring.
 
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