Hi, new to this forum.

How can you identify a 390 fe from other motors?

I was wondering if I could make a 406 fe out of a 390 fe. I heard that they have the same crank but different bore.

How much would I have to bore a 390 fe to get it to a 406 fe?

Also, is it possible to get 500-600 hp out of a 406 fe without breaking open the bank?

Thanks

Brent

 

Yes, but if you are going to bore the 390 (4.05) to the 406 (4.13) then why not use a 3.98 crank to make it a 428 (4.13 bore 3.98 stroke).
Or buy a (4.125) (4.250) stroker kit to get more cubic inches.
500-600 hp is going to take good heads, $$$$, or nitrous.
A stock 428 with nitrous will give you the horsepower you are looking for.
Check out this months issue of Car Craft, and they have a very good article from Survival Motorsports on the FE.
From the outside, you really can't determine if it is a 360-390-428, because someone could have bored or stroked your engine. The best way to know, is to tear it down and check the bore and stroke.
390 4.05x3.78
406 4.13x3.78
410 4.05x3.98
428 4.13x3.98

 

Depending on what cyl wall cores your 390 was cast with will determine *if* it can even go to 4.13. You can do the drill bit test and see what cores it has but a sonic map will tell you actual thickness and coreshift involved. While it's true some 390's can go out to 4.13 some cannot. Personally I'd keep the overbore to minimum and look at stroker kits like Maxtor suggested. The FE blocks are a crapshoot at best. Everyone is different and until you get into yours you'll only know then what your options are. Taking the block out to the maximum bore you lose any chance of a future rebuild without resleeving the block or getting another. I'd rather have good wall thickness and room for future overbore if needed. What's the budget your working with?

 

Did you mean by saying FE blocks are crapshoot at best that the cylinder walls are thin I thought The FE blocks had the thickest walls of any of the Ford engines THANKS IN ADVANCE!

 

Well coreshift is the key element that can spoil the party. There were several different cyl wall cores used depending on the block. The normal range for overbore is .030 to .060. Some 390's used a thinner wall core. Some were cast with thicker 428 wall cores that can achive a 4.13 bore. Depending on the coreshift I've had some blocks go only .030 and some to .060. Dave Shoe from FordFE.com came up with a simple field test called "the drill bit test". There is also a allen wrench test but I've found the drill bit test a bit more accurate. You need to remove the 3 freeze plugs on each side of the block to access the cyl wall cores. Then you gauge the gaps with drill bits using the shank of the bit. 17/64" bit fits snugly in your std 352,360,390's. 13/64" in some 406 and all 428 blocks. I say some original 406 blocks because some can be found with 427 wall cores. Those 406's and 427's take a 8/64" bit shank. There is some variance and exceptions but for the most part will tell you quickly what your looking at. A sonic map will tell for sure the coreshift the walls have and overall thickness. The drill bit test is really just a way to identify what cyl wall cores that paticular block was cast with. You need to scrape the sides of the inner walls with something like a butterknife first to remove any rust or caked buildup to get a accurate reading. Once you've done a few of each of these you can pretty much tell just by looking at them but the drill bits do help confirm it. The 427 blocks with the screw in freeze plugs should be left alone. Face it you hopefully know it's a 427 block and those plugs are next to impossible to remove without damaging the block. But early 427's with the press in plugs are simple like any others to remove.

 

Aint trying to be smart or nothing, but do you really have a 8/64" bit?

Could you possibly sub a 1/8" instead?


John

 

By all means yes you can convert the 64th's over to other sizes to suit your needs with bits you have. It's just the standard measurement he picked to use. Thanks I should have added that.

 

thanks guys for all your help. Also, what are a good pair of heads and intake for a 390. I was thinking of buying some heads from dove and a performer intake from edelbrock.

Thanks

Brent

 

Great info guys, but how do you tell if it is a 390?

 

check the bore and stroke... that is the only way to know for sure. Looking at the FE from the outside is not going to tell you what it is. It could have been bored and stroked by a previous owner. Some shops have a volume tester, that can tell you the volume of one cylinder. Multiply that by eight, and you can figure out the cubic inches.

 

Hmmmm you mean that my 2/16, 4/32, 16/128, 32/256, 64/512, and
.5/4 bits will work???

Since I don't have a 8/64 bit,,, I am out of luck.

 

I'll send you my drill bit stretcher. Works like a charm.

 

Sounds like a plan...might even stretch it out to a 1/8th.

 

And then some possibly.

 

i would like to know this as well. any info would be helpful.