I recently aquired a set of D3Ve heads for my motor build.They have been milled i think .015.From my understanding that would net me 95cc chambers right.

I've been told the D3's are prone to detonation and that i would have to run really low compession.I know the cam has a lot to do with it to,so i will more than likely be running a cam with around a duration of 226/234 at .050 lift.

Using these heads what kind of compression ratio should I aim for if I want to run it on medium grade 91 octane gas?


This is my first build so if yall could bare with my never ending questions I'd really appreciate it.

 

actually the D3VE are not the ones that are prone to detonation that would be the D2VE open chamber heads.
Milling .015 takes approx 2-1/2CC out of D3 heads and they are nominally 95-96cc. You would have to measure them to be sure.

With Iron heads and proper quench you should be able to run 9.5:1 on premium pump gas pretty easily (with proper tune you could run lower grade at that compression OR run over 10:1 on premium)

 

So do you think 9.5 to 1 compression would be ok with these heads.

Btw This motor is going my 4x4 and will probably never see north of 5000 rpm,which pistons will be better hypers or forged.

Thanks man,I really appreciate getting answers I can trust

 

I edited my above post after you reposted, but yes 9.5:1 is within pump gas range with Iron heads. biggest thing would be sure to get the quench correct and around .050 (.060 seems to be a threshold for it) this would take getting the pistons to within .009 of the deck with the typical felpro head gasket thickness of .041. I would say that .010 would be close enough to work just fine on 89 octane at 9.5:1
I have used hypers in slightly over stock motors in the past and never had any problems with them, others have had issues so your going to get differing views on that question but IMO hypers work fine in the application your describing. avoid detonation, high rpms and nitrous and they work fine.

 

have you tried the Fitch fuel treatment catalyst? I put one on my 88 f 250 with 460 efi. 9.5-1 compression. Had to always use premium before or it sounded like the engine was coming apart. Installed the inline Fitch unit (because i have 3 different tanks) and now I run regular fuel with no knocking, even when pulling my 14,000lb 5th wheel trailer figure it was the best investment yet.

 

Monsterbaby, you seem to know this whole head/compression thing in these 460 pretty well. Maybe you can figure this one, my new long block 460 specs:
D3VE heads (stock)
Flat top pistons (looks like they have reliefs for valves in the center)
RV cam (don't know specs, just "RV cam")
Weiand intake
Edelbrock 600 carb
Stock ignition (base timing set at 6 deg BTC)
Stock exhaust manifolds
What compression ratio do you think this motor has? Can I tell by a compression test? I'm thinking a motor with 9.5 compression should read higher with a gauge than a motor with 8.5. Is my logic correct?

 

Nope cranking compression will NOT tell you static compression ratio. The cam will have a huge affect on cranking compression. Example my 13.4:1 roller cam engine only has 155-160psi cranking compression and I have seen 8.5:1 engines with small cams have 170psi.

I have to make assumptions on your whole engine build to give you a comp ratio though since you don't know the specs or what was done to it. Example if I assume the pistons are a fairly typical flat top like the speedpro's of 4cc valve relief, assume that it's bored .030 overbore to 4.390, that someone actually bothered to square and deck the block to get the pistons within .010 for proper quench distance, assume that the heads were NOT milled and thus still approx 95cc and guess they used typical felpro head gaskets then you end up with approx 9.55:1 compression ratio. But like I said that is full of assumptions and not gospel by any means.

 

It's a Jasper basic remanufactured 460 with the flat top pistons and RV cam option, so I believe the rebuild is good. I think Jasper has a good reputation. I thought my compression was below 10:1, I run 89 octane in it and it runs just fine. Thanks for the info.