"A" vs "C" cylinder head

so if you were building an all out nitrous engine which would you rather go with and why ?

Assuming a clean sheet of paper.....I'd do the C460 head.

I just thought i heard someone say the a460 cylinder head was a better choice for large amounts of nitrous. They said something to the effect of the combustion chamber was friendlier to timing windows.

After seeing what Merkl is doing with a ton of juice on his C's, I'm impressed.

If I had to re-do it all over again.... C head

Which would be best out of the box... no port work

bruno wrote:I just thought i heard someone say the a460 cylinder head was a better choice for large amounts of nitrous. They said something to the effect of the combustion chamber was friendlier to timing windows.

I'm sure you did hear that but, as things evolve they get resolved. I remember hearing, over the years, BBC had to run at least 23* heads with spray....then it was 18*.....then 14*....etc.

There are several pieces to that puzzle and something as simple as the piston to head clearance could be one of those pieces.

I'm not a 'spray' expert but, I can tell that if one has two vastly different cyl. heads and they are treated the same one of the two is gonna be real unhappy.

Not that I know much, but how much compression are we talking?  

BigBlockRanger wrote:Not that I know much, but how much compression are we talking?  

14:1 on the c head deal

gmsmkr wrote:Which would be best out of the box... no port work

A "C" head out of the box may just as well be a simple glob of aluminum; FRPP does not sell complete "C" heads.

"A460" heads are sold ready to go.

gmsmkr wrote:Which would be best out of the box... no port work

C heads aren't a out out of the box deal.They are cast to be a make it what you want after you buy it.

thanks for letting me know about the "c" heads I had no clue I have only seen them on engines and I have never looked into a combo of this caliber this is above my pay grade

Why not move on to something better than either one? you did say large amounts of nitrous!

My good friend Schmitty gave me some great advice not to long ago and it went something like this, "call Philip Oakley". Let us know what he said please.

How much does a C head cost ready to run with similar valvetrain as the A head would come with ?

bruno wrote:so if you were building an all out nitrous engine which would you rather go with and why ?

"all out nitrous engine"
i would use the C head over the A head but it is going to cost a lot more, shaft rockers, titanium intake valves at least, finish work on the heads ( not sure if the current heads need pushrod clearance machining ) .
you get a better exhaust port, and it makes a better piston package with the valve angles .

dfree383 wrote:

garys gt wrote:How much does a C head cost ready to run with similar valvetrain as the A head would come with ?

Which A heads? What rockers? What valves?

The a460 stuff from TFS is had to beat dollar for dollar out of the box.

say the A360 heads with stainless valves and titanium retainers. I think that's how some of them come. Neither set would come with rockers would they. Wouldn't the C head be a higher performance potential head ?

If we're talking ti valves,shaft rockers,lots nitrous baller build why not go with a profiler? Thor?

garys gt wrote:

dfree383 wrote:

garys gt wrote:How much does a C head cost ready to run with similar valvetrain as the A head would come with ?

Which A heads? What rockers? What valves?

The a460 stuff from TFS is had to beat dollar for dollar out of the box.

say the A360 heads with stainless valves and titanium retainers. I think that's how some of them come. Neither set would come with rockers would they. Wouldn't the C head be a higher performance potential head ?

"C" heads can not use a similar valve train; head matching SHAFT ROCKER ASSEMBLIES ONLY on "C" heads. "A" heads come with studs and ready for OEM stud type rockers.

"C" heads are going to be a LOT of money to use with getting little performance gain; though some.
However, BEST PERFORMING between the two was asked here and money outlay was not mentioned anywhere in the original post..

At one time, there was a huge difference in the performance abilities between the A & C heads. With all the advancements of the A head, that margin has closed up quite a bit.

Unless you can find a set of C heads at a great price that will work for what you want,you are talking about a BIG jump in price for new ones,BECAUSE of the money it cost to hardware and have them ported to your combo needs.

Curt wrote:At one time, there was a huge difference in the performance abilities between the A & C heads. With all the advancements of the A head, that margin has closed up quite a bit.

You are assuming that advancements have not been made to the C heads too. I don't know that I'd call the difference HUGE for current A & C heads but, the difference is very measureable.

Isn't a profiler considered a C head?

BigBlockRanger wrote:Isn't a profiler considered a C head?

If you want to call it a RAISED RUNNER "C" type head but, it is not the same.