Re: IML: 452 heads

[sosmi@xxxxxxxxxxx]

Fred, the teflon seal is the "ultimate" seal. There is some minor machine work involved, but well worth it. The umbrella seals all seem to end up cracked, or in the oil pan. Most excessive oil consumption on a B-RB engine is through valve seals, and worn valve guides.As far a porting, the 952 head flows a little better for your application, if you want to improve anything, clean up the combustion chambers. Remove any sharp edges, and give the chamber a bit of polish work. This will reduce carbon retention, and hot spots causing detonation. Remember, Done Right, Done Once. Dave.

 

-------------- Original message --------------
From: "Frederick Joslin" <fljoslin@xxxxxxxx>

Thanks Dave:

I will go with the 452 heads and spend the money I was going to spend on hardened seats on bronze valve guides. I will probably get all new valves and definitely new exhaust valves. I also like this because the 452 heads are off the car so I can get them set up ahead of time. I am thinking of doing a little porting and this is better done as a leisurely project. I did buy one of the Mopar RB head porting templates many years ago. I am not sure where it is, but would like to try that if I can find it.   

Are the teflon valve seals the best? I thought that viton was better for general applications. 

----- Original Message -----
From: sosmi@xxxxxxxxxxx
To: mailing-list@xxxxxxxxxxxxxxxx
Subject: Re: IML: 452 heads
Date: Sat, 03 Nov 2007 15:27:46 +0000

Fred, the 452 head was improved over the 906. In particular the water passages around the spark plug area, giving better cooling. They were also enhanced for emissions. No reason they can't stand a valve job. My 78 NYB, went 200k without head removal. I would buy all new valves, this way you can reduce the amount of material removed to re-seat the valves. I would also consider bronze guide inserts, and up-graded teflon type valve seals. Just a note,I have had a few engines in the shop, that dropped the valve seat inserts out. For me, the 452 is the head of choice. Dave.

 

-------------- Original message --------------
From: "Frederick Joslin" <fljoslin@xxxxxxxx>

I have a question about the 452 heads which came on BB engines from I believe 1976 to 1978.

I have a set of these heads pulled from a 78 Cordoba 400. I know that they have hardened valve seats for unleaded gas.

The question is: Is the hardening process thick enough that these heads can take one or two valve grinds and still have hardened seat? If yes I would use the 452s, if not I would put hardened seats in the original 906s. Are the hardened seats just a better way to go?

I believe that the 452 heads are as good or better than the 906 heads which should be on my 69 LeBaron. I am developing a plan to rebuild / replace the heads on my car which would also give me an opportunity to replace the timing chain and take a good look at the valves/lifters, rocker arms, pistons  etc. 

Fred Joslin

Fred Joslin