Stock? 76 302

[92Frankenstein]

I have what I belive to be a stock 76-8 302(Mustang motor), do these have flat top pistons? How is Piston to Valve clearance? I want to put a mild cam in it and possibly a set of ported E7's i have sitting here, but I am curious if this is going to work or not? Should I just cam it and leave the heads on there? Are the 76-78 heads worth porting?

Any info would be great here.

 

[78CobraII]

The '76 heads have smaller chambers than the late '77-'78 heads, but make up for it with a dished piston.

If you are going to make much more horsepower with the '76 block, you'll need to swap those pistons.

The '76 head won't flow nearly as well as the E7 head, but it has smaller chambers which make for a higher compression ratio. Especially important with the dished pistons.

If that '76 block has not been rebuilt yet, now would be a good time!

 

[92Frankenstein]

The '76 heads have smaller chambers than the late '77-'78 heads, but make up for it with a dished piston.

If you are going to make much more horsepower with the '76 block, you'll need to swap those pistons.

The '76 head won't flow nearly as well as the E7 head, but it has smaller chambers which make for a higher compression ratio. Especially important with the dished pistons.

If that '76 block has not been rebuilt yet, now would be a good time!

Well, I am buying a weiand blower for it, and I am curious what I should swap out to run 6-10# of boost. The motor has about 6,000 miles on the new long block. I was curious if I should just upgrade springs and rockers on the heads I have with a mild cam, or if I should switch to some E7 heads and keep the cam that is in there now (stock) with the blower? Or am I looking at replacing the pistons/rods either way? Like I said, this motor is brand new, and it runs flawlessly, so I am curious as to of what I can use and what I have to scrap.

Thanks for the input and help,
Brian

 

[Blue Thunder]

The '76 head won't flow nearly as well as the E7 head, but it has smaller chambers which make for a higher compression ratio. Especially important with the dished pistons.

The E7 heads have the same 1.78"x 1.46" valves and port sizes as the early non-truck heads, so where does the extra flow come from?? (Or are you referring to the E7 ported heads?)

 

[92Frankenstein]

The E7 heads have the same 1.78"x 1.46" valves and port sizes as the early non-truck heads, so where does the extra flow come from?? (Or are you referring to the E7 ported heads?)

What is the difference between the heads than? So I should port the heads that are on there and have the same outcome?

 

[Blue Thunder]

What is the difference between the heads than? So I should port the heads that are on there and have the same outcome?

Ford only went with the E7T castings because they had re-designed the 302 heads the previous year('86) with smaller ports and some "high swirl blah blah crap" and those were a complete p.o.s. Since Ford had already scrapped the old original 302 castings, they needed something to put on the '87 HO motor to replace that god awful 86 head. Hence, Ford turned to the Truck division and ended up using the '87 302 truck head.(E7T)
If it wasnt for that screw up in '86, the '87 and up 302 HO heads would still be the same exact castings from the '60s and '70s, with the only variance being combustion chamber size and spark plug diameter.

P.S. Though I'm only speculating on this, it's possible that the 302 truck head castings are slightly thicker and tougher than the older 302 heads, due to the greater heat and potential for abuse of the truck application. If this is true, then the E7Ts could have more meat around the ports for porting purposes. But as I said, it's only speculation, as I've never cut one in half and compared the casting thickness, nor have I weighed them.

 

[Mustangj]

I would pop the heads off and check the piston situation first. If the engine has been rebuilt it likely has flat top pistons. If it has flat top pistons I would run the E7 heads with the blower. 1976 heads should be 58CC. 58CC with flat tops makes for a fair amount of compression. I run a 1975 block and heads with flat top pistons, Edelbrock performer cam, intake, carb and 100hp nitrous kit. If you have both sets of heads around I would run the E7's to lower the compression a bit to run your blower. If the pistons are cast and not forged you are pushing your luck. My pistons are not forged, so far so good. If your pistons are dished run the 1976 heads. This combo would be ideal for blower. I don't have my specs handy but a 76 II engine has low compression around 8.5:1. If you run cast pistons and a power adder be prepared for engine failure. I have already started to collect parts for my replacement engine. When it blows (and it will) I am going to build a 302 H.O with a forged pistons, a mild roller cam and Edelbrock performer heads. For now it is foot to the floor with the nitrous set to kill

 

[92Frankenstein]

I would pop the heads off and check the piston situation first. If the engine has been rebuilt it likely has flat top pistons. If it has flat top pistons I would run the E7 heads with the blower. 1976 heads should be 58CC. 58CC with flat tops makes for a fair amount of compression. I run a 1975 block and heads with flat top pistons, Edelbrock performer cam, intake, carb and 100hp nitrous kit. If you have both sets of heads around I would run the E7's to lower the compression a bit to run your blower. If the pistons are cast and not forged you are pushing your luck. My pistons are not forged, so far so good. If your pistons are dished run the 1976 heads. This combo would be ideal for blower. I don't have my specs handy but a 76 II engine has low compression around 8.5:1. If you run cast pistons and a power adder be prepared for engine failure. I have already started to collect parts for my replacement engine. When it blows (and it will) I am going to build a 302 H.O with a forged pistons, a mild roller cam and Edelbrock performer heads. For now it is foot to the floor with the nitrous set to kill

Cool, the motor is remanufactured. I am sure it has non forged flat tops, but like said, I do not know for sure, I will have to check when the time comes. So, if they are flat tops, should I go with forged? Forged flats or w/ releifs? And E7's?

 

[92Frankenstein]

Also, does anyone know what kind of power I would put down with the E7 set up and 10 pounds of boost with a 142cid B&M blower? All other happy bolt ons, headers and what not?

 

[Blue Thunder]

I'm not very experienced with forced induction systems, but I figure 240hp at the wheels n/a with mildly ported stock heads and a good tuning, I guess that blower setup might add 30%-40% more? Maybe 310 - 320 at the wheels? Just a rough guess.

 

[Johan]

Ford only went with the E7T castings because they had re-designed the 302 heads the previous year('86) with smaller ports and some "high swirl blah blah crap" and those were a complete p.o.s.

MM&FF did a comparison of various heads a few years back and I was surprised to see the '86 heads made more power than the E7T's below 4000rpm. (Barely more, but more) But over 4 grand, the '86 heads dropped off the chart. Not a complete p.o.s., but misapplied in a Mustang - better suited to some more mundane passenger cars.

 

[Blue Thunder]

MM&FF did a comparison of various heads a few years back and I was surprised to see the '86 heads made more power than the E7T's below 4000rpm. (Barely more, but more) But over 4 grand, the '86 heads dropped off the chart. Not a complete p.o.s., but misapplied in a Mustang - better suited to some more mundane passenger cars.

Yeah, the little high-swirl ports had decent low-speed velocity, but who in their right mind would have designed such a thing for a performance car??

 

[Mustangj]

Also, does anyone know what kind of power I would put down with the E7 set up and 10 pounds of boost with a 142cid B&M blower? All other happy bolt ons, headers and what not?

Check this out:

http://www.holley.com/HiOctn/TechServ/TechInfo/SCTech.html

http://www.holley.com/HiOctn/ProdLine/Products/AMS/SC/SCK/Pro-Street.html

The B&M blower is no longer made. It was a Wiend product. Wiend (a Holley brand) still offers the blower. The 174 is the model that fits on a small block Ford. When I worked at the speed shop I sold a few for Chev's. They work really well. I forget the exact HP increase, but I think you are looking at 100 extra horsepower. I searched the web and there really is no good info on them. The Holley catalog had all the specs, I can't find my copy I would visit your local speed shop and have a look at either a Wiend or Holley product catalog. Holley's web site sucks! I would run the 174 as it comes in the kit (small boost level) on your stock engine. When it blows-up build a supercharger specific engine. Going into an engine to switch pistons makes no sense. If you already have the 1976 engine rebuilt and ready to go, just use it as is. The engine will likely last a few seasons with the small blower with low boost. When it blows-up build a Blower specific engine When it blows, it will likely have piston damage. A basic rebuild with a over-bore, re-ground crank, re-sized rods, re-ring, re-bearing and add low compression forged pistons. My engine only has a few thousand miles on it but, I bought a 302 H.O core yesterday because you always need more horsepower right? It is never to early to start building your replacement engine

 

[perce111]

According to the old B&M Supercharger Tech Manual the 144 Blower on the 302 with stock heads [pre 87] B&M 90770 cam and a 750 carb the HP was 335 @5500 rpm
They substituted a set of Motorsport heads [ 1.94 I & 1.60 E] and the HP was 410
With the same cam,carb and Motorsport heads the 351 had HP of 440.
As previously stated they now list the 174 blower for the SB Ford so the above info is dated but decent for comparason.

Enjoy

 

[Blue Thunder]

According to the old B&M Supercharger Tech Manual the 144 Blower on the 302 with stock heads [pre 87] B&M 90770 cam and a 750 carb the HP was 335 @5500 rpm
They substituted a set of Motorsport heads [ 1.94 I & 1.60 E] and the HP was 410
With the same cam,carb and Motorsport heads the 351 had HP of 440.
As previously stated they now list the 174 blower for the SB Ford so the above info is dated but decent for comparason.

Enjoy

Looks like even the motorsport heads are restrictive for the blower, since the hp only rose by 30 with the 351. That probably indicates that some nicer heads on the 302 will make substantially more hp with that same blower setup. In fact, since blowers make low end torque by their very nature, I would bolt on the biggest, gnarly-ist set of heads I could find(and afford) for it.

 

[perce111]

My thoughts exactly.
My choice, cause I like to do things the hard way is a 302 [got that] enlarged to 347 with 351C [2.19 intake] 2 barrel heads setting on top [got that] a 5.0 truck lower EFI intake [got that] with a Holley 174 bolted on top or maybe a MagnaCharger.
I think that this combination would make lots of powerat any RPM range you can think of.
Price MotorSports make the intake adaptor plates and my local machine shop can make the 174 to intake piece or if you go Magna charger I think they have the right pieces to mate their stuff.
This would definately be a FORD to be reckoned with and if the camming was kept reasonable sweet on the street.
Later