'85 460- Heads, how many CC's?
 

How many CC's are the stock heads on a '85 460? Out of a F250, if it matters.

I'm trying to decide the last few aspects of my new build here, with 72CCs my pistons are 8.0-1. I'm debating between shaving my heads to increase compression, or tossing on a pair of smallish turbo's and tunning 6-7psi of boost.

I'm leaning towards the higher comp route, largely because I feel I'd be a fool to try and make my motor work well with the turbos I had in mind, instead of buying turbos that work well with my motor...

Lets see, I visit a Probe forum for my Probes, GPz550.com for my bike, reeffrontiers for my reef tanks, and a site for Tbirds, so I'm all over the place, but man, I miss this place the most ;) I forgot how much I love my bigblock till the parts arrived today [*grin*]

Chris,

An '85 460 should have D3VE heads like my '79 I believe. I think the common quoted cc for those chambers is 95cc. That's the value I've been using in my calculations.

Not sure what kind of piston would give you 8:1 with 72cc combustion chambers though .. seems to me that would have to be a mighty dish. That doesn't sound right at all.

My stock 460 has 22cc dish pistons I believe, and that gives 8.0:1 with 95cc chambers.

I ordered a engine rebuild kit from Norther Autoparts, not knowing what pistons were in it, only that they were hyper's.

When they arrived yesterday, I took the number off them and googled it

H418P Speed Pro

I didn't find much infor on them, but the two sites I did find comp numbers in, one said 8:1 w/ 72cc, and the other said 79-87 8:1.

Maybe I'll see if I can call speed pro?

Let me ramble on for a minet on this. I have just finished working on a set of D3VE heads. I didn't cc them before I started but after having a little miled off to be shure they were flat and doing a little grinding on them and general clean up the were matched to 90 cc so it is moste likley that the origanal chambers were 95cc. It will depend on if they have ben milled before. Be aware if you are rebilding thease heads you will want to install hardend seats the factory onley inducton hardend the factorey seats (exaust) aney grinding will likley cut through the hard layer. I was watching when they cut for my new seats and the cutter onley made about 2 turnes and was through the hard part.

Bill

The heads are in the hands of my machinist, he'll be completely rebuilding them, if he hasn't already. I just hate to bother him with stupid stuff like how many CCs are my heads over the phone (he hates phone calls, has to turn everything off to answear the phone) and I always forget when I'm up there.

I'm picking up another motor tomorow from him, I'll try and ask him more, and get my casting number. Was D3 the most recent casting in '85? I'm going to have them shaved to meet my target CR of 9:1.

If you engine is a 1985 F250 460, then you have D3VE heads. An HP418P piston will put you at about 8:1 c/r with the D3 heads. You would have to mill in excess of .060" to get your D3's down to the 80cc's necessary to meet your desired 9:1 c/r, and I think that's pushing it on the cylinder head machining and expense. Futher, it opens up other situations such as cylinder head-to-intake manifold flange fitment issues...which can be corrected by further millling on the cylinder heads (intake flange side), but you're really basardizing a set of heads to get your 9:1 compression ratio when there are easier ways.

Flat top pistons and D3VE's will get you somewhere around 9.3:1. The Keith Black KB206 will put you at around 8.9:1.

Paul