390 build-up ?'s

[HuKares]

I'm cosidering doing a build-up and rebuild of a 390 I have. It's out of a '73 truck. I've been looking for parts such as high-compression pistons (like 11:1?), and information on what budget (i.e. stock) heads to use and how much cam is compatible. So far I haven't found the information and the only pistons I've found net me under 10:1. Also, what oiling system mods are needed if any for higher rpm durability? I'm trying to do this on somewhat of a budget so no aluminum heads. This is going to be for a dragstrip only vehicle running on race fuel and I'd like to get the most power I can out of it without breaking the bank. As far as how much breaks the bank, that depends on the economy of the mod (hp/$).
Thanks for any help.

 

[danny clemens]

I don't know myself but if you go to the FE forum I'm sure those guys there could help you.

 

[HuKares]

I don't know myself but if you go to the FE forum I'm sure those guys there could help you.

Is there an FE forum? I can't find it.

 

[ddonaca351]

basically* (rule of thumb here) all the tricks that work on the 427, work on the 390.

DD

 

[65ShelbyClone]

Is there an FE forum? I can't find it.

No, there isnt. There isnt even a bigblock forum.

 

[ddonaca351]

almost forgot... www.strokerkits.com

for 1995.00 you get all good SCAT parts and 450 inches worth of 390...

With a good set of stock FE heads, thats a 500hp motor, with good aftermarket FE heads, its probably good for 550 in a solid street tune.

DD

 

[Darren390]

There is a FE forum - go to www.fordfe.com

Very knowledgeable and friendly guys!

Darren

 

[TireSmoknWindsr]

check out ford truck enthusiast forums too. there is an fe forum there. some guys are even running efi setups

 

[danny clemens]

Sorry that I didn't give you the address. There are some very informative people on the site. One being Royce Peterson.

 

[Max Power]

Here is another FE forum:

http://www.network54.com/Forum/74182

 

[HuKares]

Thanks, that's what I was looking for. It never came up when I was google-ing.

 

[D.Hearne]

Sorry that I didn't give you the address. There are some very informative people on the site. One being Royce Peterson.

Royce? Informative? Yea on a few things, but he's also got a lot to learn, thinks he knows it all. He thinks that just because he's in possesion of a handful of 427's, that he's the foremost authority on them, but nothing could be further from the truth. As for building a 390, there are 10+ to 1 flattops available, Speed Pros come to mind for forgings. As for heads, I'm partial to the C8AE-H and D2TE's that your 73 motor has. Others seem to think the earlier castings with the so called "tall" ports flow more, but the C8 & D2 heads have the later medium riser 427 ports and flow just as well with a little work and CJ sized valves. As for intakes, I like the factory medium riser 427/ 428PI intakes the best, if you can't find one, Blue Thunder markets a repop of them. Oil mods? just enlarge the passages and smooth out the corners, run a high pressure pump ( not high volume) The stock rods with ARP bolts are the equivalent of the LR 427/428CJ forgings ( all FE rods were forged) The cast cranks are also tough as nails, just about bullet proof. With a cam in the range of a .550 lift/290 degree ( advertised ) duration, a 750 carb and headers, 400 hp is what you'll get from a 390 without trying.

 

[HuKares]

Royce? Informative? Yea on a few things, but he's also got a lot to learn, thinks he knows it all. He thinks that just because he's in possesion of a handful of 427's, that he's the foremost authority on them, but nothing could be further from the truth. As for building a 390, there are 10+ to 1 flattops available, Speed Pros come to mind for forgings. As for heads, I'm partial to the C8AE-H and D2TE's that your 73 motor has. Others seem to think the earlier castings with the so called "tall" ports flow more, but the C8 & D2 heads have the later medium riser 427 ports and flow just as well with a little work and CJ sized valves. As for intakes, I like the factory medium riser 427/ 428PI intakes the best, if you can't find one, Blue Thunder markets a repop of them. Oil mods? just enlarge the passages and smooth out the corners, run a high pressure pump ( not high volume) The stock rods with ARP bolts are the equivalent of the LR 427/428CJ forgings ( all FE rods were forged) The cast cranks are also tough as nails, just about bullet proof. With a cam in the range of a .550 lift/290 degree ( advertised ) duration, a 750 carb and headers, 400 hp is what you'll get from a 390 without trying.

Thanks for the reply,
Sounds like a good setup. I was planning on ARP'ing the motor. My only question is this: I heard at one time, I haven't found it again though, that the CJ size valves do not fit properly in the smaller 390 bore and that you may have to notch the cylinder wall slightly. Is that true or at what point is that true? The speed pro pistons I saw come in at a little under 10:1 or do you deck either the block or the heads to get the higher compression with them?

 

[D.Hearne]

Thanks for the reply,
Sounds like a good setup. I was planning on ARP'ing the motor. My only question is this: I heard at one time, I haven't found it again though, that the CJ size valves do not fit properly in the smaller 390 bore and that you may have to notch the cylinder wall slightly. Is that true or at what point is that true? The speed pro pistons I saw come in at a little under 10:1 or do you deck either the block or the heads to get the higher compression with them?

Yea, I've heard that too about CJ valves in a 390, but I've never tried them. I've heard of many that have though and don't recall there being a problem. As for the Speed Pro's, I don't recall what size chambers they're rated for , it's possible that their advertised comp ratio is with the larger chambered heads and not with your D2TE's. Just do the math to figure what they'll get with D2's.

 

[PoliceInterceptor]

The speed pros will get you about 10.6 (or in my case exactly 10.6) after the block and heads are cleaned up. Also most aftermarket valves usually do not have the same volume as stock thus lowering the head cc. My C8AE-H ended up at 66cc after Stainless CobraJet valves and a clean up surface.

Diamond racing pistons has a nice assortment of FE pistons as well, but with out alum heads even the 10.6 is really pushing it.

 

[HuKares]

The speed pros will get you about 10.6 (or in my case exactly 10.6) after the block and heads are cleaned up. Also most aftermarket valves usually do not have the same volume as stock thus lowering the head cc. My C8AE-H ended up at 66cc after Stainless CobraJet valves and a clean up surface.

Diamond racing pistons has a nice assortment of FE pistons as well, but with out alum heads even the 10.6 is really pushing it.

As far as too much compression goes, the limited use of this project gives me the option of running race gas. I would like a higher compression, 10.6 sound pretty good. According to Speed- Pro's website, a 390 .030" over with 67.1cc heads comes out to 10:1. They don't list the head gasket thickness or the cc's of the pistons so I could figure it out. Also, it says on their site that there is a deck clearance of .015". Doesn't this mean that the piston stays that far from the top of the block and that to zero deck the pistons, I would need to shave that .015" off? Is that what you did PoliceInterceptor? Did you also shave the heads or just a minimal clean up?
Thanks.

 

[D.Hearne]

You can mill the .015 to get a zero deck, and there's also the possibility of finding and using the factory .020 thick steel shim gaskets to get even more squeeze.

 

[PoliceInterceptor]

Speed Pro figures the compression with Fel Pro head gaskets. (~10cc) They also spec the piston valve relief at 10cc and mine worked out to more like 7cc. (This seems to be normal) my block was zero decked, and the heads were cut to clean up. (I do not know how much, but they were cut equally.) I wanted about 68cc but due to the valve and the clean up 66 is what they ended up at. In addition, I used Victor Head gaskets that are ever so slightly thinner than the Fel Pros are.

A cc here, a cc there it all adds up so you just have to consider the advertised compression as a guideline at best.

Dennis at DSC has factory steel shim gaskets. He can also spec you a set of custom Ross or JE pistons.

 

[HuKares]

Thanks for all the questions you've answered so far.

The custom pisons are more than I want to spend and I think I can make the Speed Pro's work for me. My only other concern are valve reliefs. I plan to run a larger solid flat tappet cam. The one I like is Comp Cams #33-638-5 which is the smallest of the drag race series cams they sell. I know what I need to do as far as making the heads take the cam and the lift (.590 on the exhaust) but will I need to enlarge the valve reliefs in the pistons to make this cam work? I understand if you can't answer this one. I'm sending an email to Speed Pro and Comp Cams to see if they can help also. Any examples of a large cam being used with these pistons?

Thanks again.

 

[Timmy]

I just dropped my newly rebuilt 390 in the 69 Mach 1. All the advise above is good stuff. Also, as mentioned above, www.fordfe.com is a VERY good source of information. You can also try www.clubcobra.com You would be surprised how may of those guys are running 390.

I’m running a milder setup than you want so I can’t answer your questions but I know some of the guys over on the two forums above are running cam lifts of .600 so they should be able to help you with that.

Tim