You probably will not get by on pump gas. 88-92 460 pistons have the shallowest dish (0.080") of any 460 oem piston and have the standard 460 dish shape. What pistons are in it? For instance, if they are Sealed Power rebuilders and are 0.028" or so in the hole then the ratio will be 10.8-11:1 or so. The rest of the setup sounds good but you WILL need more cam duration to help bleed off some of the cylinder pressure. What are the 0.050" duration figures? Advertised figures are worthless for evaluating engine builds. It all depends on the pistons, oe or aftermarket domes.

 

I apologize, but I answered your question somewhat incorrectly. If the pistons are stock 88 pistons and the block has not been decked, than you would have about 10.2:1 with dove-c heads. Alot of variables involved, need more info. Thanks.

 

9.3:1 to 10.5:1, depending on the actual rebuilder pistons used (dish volume). This does not include decking the block, which would increase compression ratio.

The cam is probably fine for your low end grunt application, and going much bigger in order to reduce low rpm cylinder pressure will hurt low end performance. Therefore, determine your actual mechanical compression ratio and adjust it if necessary, not by way of the camshaft.

Paul

 

Interesting, I have been told many times on this forum by fellas (that I know they know what they are talking about) that my engine would have too much dynamic with a 204 214 484 510 at 10.6:1 static even though I ran the thing on the street for 20k miles very specifically tuned and it still wanted to ping. So how could another engine, almost just the same, get away with the same compression scenerio with no issues in order to not err on the side of hurting low end performance? I guess it is all weighing on the specifics of the combo, undisclosed at this time. Not everyone has the financial means to re-invent the wheel in order to get things 100% correct with their engine and may have to correct issues with unconventional means. This is what I dislike about forums, (although ours is by far the best), nothing is for sure when we dont know all of the specifics. It has taken me 10 years to build my first 460 correctly(all the while knowing what I am doing nursing my tired 429 along) and I still don't work at NASA.

 

thanks for the help I'm still alittle comfused becuase on pirate 4x4 i was told 11.5:1 by one person and 10.5:1 by another which is still cutting it close so i think that shoots my plan in da foot so it looks like i'm gonna run the D3VE heads I have. The engine hasn't been torn down yet but the previous owner swears it has less than 30,000 miles on it so i was just gonna use it and i would assume they are OE rebuilder pistons. With D3VE heads what would the compression ratio be? I wanted to be kinda close to 400 hp but in all reality 350 hp whould probably be fine as long as i have enough torque to get the 40" tires spinning if need be. I'm replacing an old worn out 7.3 idi turbo with this 460 and the 7.3 is rated at 190 hp and i think 365 ft lbs and it did alright so 350 hp would be amazing. I was gonna use the D3's as practice heads to test out my hand at porting but I think I'm gonna run em now for a low end grunt engine would you all recomend any porting? and is a 770 TA too much carb they make a 670 truck avenger. thanks for all the help i really appreciate it i'm deployed to afghanistan nad am coming home real soon so all i can think about is my build up. god bless

 

I'm sorry but heres some more info the D3VE's have been decked and the valves and seats cut already they just need valve springs and rockers. will the rockers off of the DOVE-C's work? the DOVE-Cs still need magnafluxed and redone its kinda funny cuz it is actually 1 DOVE-C and 1 C9VA head it came off an all original late 69' lincoln my guess is they had some C9va's left over so they threw em on there? Weird i was just gonna run it anyhow. also I have the pushrods of off the 69' engine and the pushrods for the 88' fuelie engine running D3VE heads would either of these pushrods work? what is ya'lls opinion on DUI HEI dizzys this truck has to be reliable so i can drive to the desert and go wheeling hard without getting stranded. I also have an 85' block and crank the block has been dipped and magnafluxed and just needs cam bearings, freez plugs and a hone, the crank needs ground its kinda knarly I put that in there in case all you 460 gurus know of a better setup i can do. trying to go budget as possible becuase i still have to finish the rest of the drivetrain Detroits are expensive.

 

I'm sorry but heres some more info the D3VE's have been decked and the valves and seats cut already they just need valve springs and rockers. will the rockers off of the DOVE-C's work? the DOVE-Cs still need magnafluxed and redone its kinda funny cuz it is actually 1 DOVE-C and 1 C9VA head it came off an all original late 69' lincoln my guess is they had some C9va's left over so they threw em on there? Weird i was just gonna run it anyhow. also I have the pushrods of off the 69' engine and the pushrods for the 88' fuelie engine running D3VE heads would either of these pushrods work? what is ya'lls opinion on DUI HEI dizzys this truck has to be reliable so i can drive to the desert and go wheeling hard without getting stranded. I also have an 85' block and crank the block has been dipped and magnafluxed and just needs cam bearings, freez plugs and a hone, the crank needs ground its kinda knarly I put that in there in case all you 460 gurus know of a better setup i can do. trying to go budget as possible becuase i still have to finish the rest of the drivetrain Detroits are expensive.

I don't think it could possibly be original as C9 is a 69 DOVE-A is 1970 and DOVE-C is a 1971 head. From my understanding though all of them are essentially the same so it is very possible that one head needed to be replaced at some point and they just used the DOVE-C.

 

Next step is pull the heads and see what pistons exactly you have in the block. We need to know how deep the dish is, the dish shape, and how far below the cylinder head surface the piston is at its highest travel. Essentially, if it has the deep dish pistons(.240" deep) then you would be ok with the dove-c heads. If it has the correct year pistons(0.065"dish), then all this math were talking about will be vital in choosing the dove-c's or not. No other advise on compression ratio can be given until then. The dove-c model rockers will not work on the d3 heads. Use the pushrods out of the fi engine, the earlier ones might be too long. A GM dizzy would be an ok choice, only if the mechanical advance curve is checked and corrected.

 

460

I run that combo in my jet boat, It runs great and no ping = none. It runs on pump premium. I ported the DOVE's and stuffed them with big valves. Paul Kane has driven the boat & probably forgot to mention it in his response. He was here when I lit it up the first time. I use a Weiand Stealth & a Holley 780 & a NOS 30 year old Sig Erson Hyd cam.

 

Ya they must have replaced the head sometime way back and I didnt see thermactor holes in either head so If I did want to run those heads would I be good to run them even though they are different castings? I'm so confused on what I want heads to run now. I am gonna be back stateside in a couple days and i will tear off the EFI heads and measure how far down in the hole the pistons are at TDC so it that will be a for sure way to tell thanks for all the help, I really appreciate as soon as I get the heads off I will post my findings.