head ?

[evanbrendel]

so i have 452 heads now are 915s better for compression and flow? they are small valve 915s but if i have them redone i will have the bigger valves in them

 

[69 Runner]

By smaller valves I'm assuming you mean they have the 2.08 & 1.60 valves. The intake is the same size, but the exhaust should be a 1.74. Chances are if you have a valve job done on the 452s you'll lose the induction hardened surface on the exhaust seats so assuming you want to retain hard seats you'll have to have them installed on either set of heads. So moneywise the difference will be buying 1.74 valves for the 915s.

You should cc both sets of heads to see the difference in the chambers. 915s aren't as small as people think.

 

[daredevil]

915s have closed combustion chambers for better compression is the only diff i believe. 452,s aregood heads with port work. search mopar muscle head comparison. was a very good article

 

[evanbrendel]

ok well the 452s are on the car running now and the 915s need total rebuilt so i was wondering if it would be worth my time to put them on a 78 440 are the 452s correct stock heads in 78?

 

[daredevil]

read this and then you,ll be able to decide http://www.moparmusclemagazine.com/...ylinder_heads/aftermarket_cylinder_heads.html page 2

 

[evanbrendel]

thats a great article

 

[Meep-Meep]

If you have the option of using 915's I'd do it. They have a much better port design over the 452's or the older 516's - something not mentioned in the article. Like Runner said, too much grinding on the 452 seats will put you back to square one so if it comes to that might as well rebuild the better castings.

Right now I am doing up some non HP 915's with 2.14 / 1.81's. The exhaust seat was cut from 1.6 to 1.81 and hard seats added. A little pocket work, finish the 3 angle valve job and should be good to go.

I have the KB pistons (237 I believe) that are the ones to use with closed chamber heads. The compression height is similar to the six pack pistons. Definitely not for reg gas!

 

[evanbrendel]

yea i think im going to

 

[Patrick]

If you blind the bowls ti the big valves in real world seat of the pants they out perform all but the Alum. heads. For valve seats I still don't believe one needs harder valve seats. My sons 72 440 Charger has over 900,000 miles on it. The valves and seats are still nice. The only reason its apart is that I didn't want to restore the body for him and not do the powertrain too.

 

[Revhendo]

Just out of curiousity. What's the cost of doing the HP work to an old set of heads, be it 915's or 452's versus buying a set of the ready to go Aluminums that are out there now?
I was just wondering because the cost of the new heads is coming down and I spent a crapload of money on the heads on my small block stroker.

 

[696pack]

Just out of curiousity. What's the cost of doing the HP work to an old set of heads, be it 915's or 452's versus buying a set of the ready to go Aluminums that are out there now?
I was just wondering because the cost of the new heads is coming down and I spent a crapload of money on the heads on my small block stroker.

With the cost of machine work today the aftermarket heads are a better deal. If you are going to run in a stock class or something like F.A.S.T. then you need to have the correct factory heads to be legal, so many people bite the bullet and pay the money to have the original heads worked over.

 

[19mopar65]

With the cost of machine work today the aftermarket heads are a better deal. If you are going to run in a stock class or something like F.A.S.T. then you need to have the correct factory heads to be legal, so many people bite the bullet and pay the money to have the original heads worked over.

I agree!! If you take into consideration all the money its gonna take to machine the old heads cauz ur gonna pay for cleaning, magging, valves (if going bigger), bigger guides (if going bigger), grinding seats, valve job, and port work (if wanted). Don't get me wrong I have nothing against the strong cast iron heads but, if I didn't get my work done for free cauz I was workin there I would have gone with some nice aftermarkets myself.

 

[evanbrendel]

well this way i can pay a little at a time if i buy aftermarket its all at once plus my car is my daily driver i realy dont need anything radical and i dont realy want aluminum also

 

[Meep-Meep]

If you blind the bowls ti the big valves in real world seat of the pants they out perform all but the Alum. heads. For valve seats I still don't believe one needs harder valve seats. My sons 72 440 Charger has over 900,000 miles on it. The valves and seats are still nice. The only reason its apart is that I didn't want to restore the body for him and not do the powertrain too.

Just to comment on the high mileage you got out of your 440 heads. It was common for the car companies to induction harden seats as early as 71 or 72. One guy I know had a 60's Ford 6 cyl head done with just a plain valve job, put it all together and drove to LA (~600 miles) and the exhaust seats were pounded out when he got there. He noticed the car was running bad and later found out the extent of the damage.

 

[Meep-Meep]

Since I'm replacing everything my heads will be pretty pricey, but I don't think they will approach the $1500.00 mark. I suspect I will be in there for about half. I just have a bunch of 915 castings and figure I should use them.