What can I get away with? 1986 shortblock...

gxnos

Founding Member
Apr 14, 2002
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Birmingham, MI
So I know all about the 1986 HO 302... E6 heads, true flat top pistons...

What do you think I can get away with as far as mods without running into problems with the shortblock? I hear of people running B cams and even 40x heads with no problems.. what do you think? It would be nice to know what I can safely bolt on to the motor without building the shortblock.

I also wanted to note that I ran the part number for the 86 pistons and it said
"E6ZE-6110-BA FORGED ALUMINUM" .... forged?? I thought forged started in 1987.
 
Yea, the pistons and rods all came forged pretty early on, and its a common misconception that they weren't. I don't have the dates in front of me, but I almost want to say that ALL the 5.0 cars had forged stuff, all the way back to 79- though I could be wrong on that. Of course, the crank is cast.

As far as clearance, its my understanding that TrickFlow TW heads will USUALLY clear the pistons because of the unique valve orientation. But whenever you build the top end, you have to check for PTV clearance anyway. A cam grinder (or supplier like Comp) may be able to give you insight on that.

That's not to say that people haven't got other heads to fit, I know I've heard of it. I've heard of a LOT of people getting E7s to work.

You also have the option of notching the pistons by hand with a notching tool. A machine shop might be able to point you in the right direction there.
 
Forged aluminum pistons started on the 5.0 H.O. in 1985 through early 1992, even though in 1986 they made the 1yr only flat top piston it was still a forged unit. it was in late 1992 that the hypereutectic piston showed up.

All 1979-93 small block V8's had forged steel rods and cast iron cranks.

E7 heads have been swapped onto the 86 motor w/o issues, I have also heard of this done with guys running B303 cams and still where okay. I have heard of them running TW heads like NikwoaC stated but with a stock cam. I'm not sure about the gt40 valves clearing though. I'm with NikwoaC , checking ptv is cheap insurance more so of going with something other than E7's with stock valves.
 
thanks for the great info guys. i think im going to just go with some E7 heads and a small cam. i will check the PTV for sure. I just want to get as much as i can out of this 86 shortblock as i can.

thanks again!
 
thanks for the great info guys. i think im going to just go with some E7 heads and a small cam. i will check the PTV for sure. I just want to get as much as i can out of this 86 shortblock as i can.

thanks again!

You'd actually be better off going with better heads and a stock cam. The stock HO cam is pretty stout, but the E7s don't flow very well without porting. I've seen builds make 375-400 flywheel horsepower with a stock cam.
 
You'd actually be better off going with better heads and a stock cam. The stock HO cam is pretty stout, but the E7s don't flow very well without porting. I've seen builds make 375-400 flywheel horsepower with a stock cam.

that sounds like a good idea... but I heard a lot of heads wont work with the 86 shortblock, even with the stock cam. I would assume it has to do with the valve size / configuration. Does anybody know what I should get?
 
the 86's are flat top , some people get away changing heads without problems, you could fly cut the pistons inside the motor

I would rather stay away from putting fly cuts in the pistons. I would like to know what is a decent head I can bolt on there and get as much power as I can with the stock cam. I see the ones listed above, but Im wondering what else. Don't want to guess and buy, ya know
 
I would rather stay away from putting fly cuts in the pistons. I would like to know what is a decent head I can bolt on there and get as much power as I can with the stock cam. I see the ones listed above, but Im wondering what else. Don't want to guess and buy, ya know

Like we said above, Twisted Wedge heads are your best bet. All other aftermarket heads (that I know of) use the standard '87+ Ford valve placement, so they are more likely to cause interference. You can always call Trick Flow and talk to one of their tech reps.
 
Really thinking about getting these heads now:

Trick Flow Specialties TFS-51400002 - Trick Flow® Twisted Wedge® Street Cylinder Heads for Small Block Ford – SummitRacing.com

"They don't require flycut pistons for use with cams up to the specifications listed--no other 2.020 in.-valved head for small block Ford offers these features!"

"Maximum Valve Lift (in) 0.540 in."

So according to this info, I can run these heads with a decent cam without running into PTV clearance problems. I think I will still call up trick flow to see what they say about it.