Engine Questions about 86 302

[86bluecobra]

I have recently bought another 86 mustang. This time it is an auto with t-tops. I just bought a cobra intake with a 75mm tb on it (i know the 75mm maybe a bit big). I have a set of the old holley systemax II heads. 1.94 intake valves.

While I was thinking about installing these heads on the 86 I remembered the reason why I bought them. The 86 302 doesn't have valve reliefs notched in the pistons as I recall. I think I bought these because at the time I think they were the ones that would fit on that motor and work with those pistons. Does anyone remember anything like that about these heads?

I will still do a piston valve clearance check.

Also the car is MAPS so I was curious about this head intake combo and any possible issues on it.

Should I cam the car with this combo? If so which? I don't know that I will be doing a MAF upgrade anytime soon.

Should I use the stock injectors or upgrade them? What are the ramifications for doing that?

Thx for the help in advance.

 

[NIKwoaC]

The only heads that I know of that will work with the '86 pistons are Twisted Wedges. Anything else is a crap shoot. Aftermarket cams will exasperate the issue.

Run the 75mm TB and have fun.

If you do end up putting heads and a cam on it, MAF conversion is pretty much mandatory. As are bigger injectors.

 

[86bluecobra]

The only heads that I know of that will work with the '86 pistons are Twisted Wedges. Anything else is a crap shoot. Aftermarket cams will exasperate the issue.

Run the 75mm TB and have fun.

If you do end up putting heads and a cam on it, MAF conversion is pretty much mandatory. As are bigger injectors.

What size injectors would you go to?

 

[NIKwoaC]

24? 30? Depends on what kind of power levels you're shooting for. Google "fuel injector calculator".

 

[86bluecobra]

I was reading the old holley systemax II kit and they recommended 30lb injectors. I guess I should look at fuel rails an adjustable fuel regulator and upgrading the fuel pump as well.

 

[Noobz347]

What size injectors would you go to?

19's with adjustable fuel pressure regulator.

If you decide to add boost then larger injectors will be needed.

On a side note: Keep running the 86 cam... It's no slouch, it's sounds great, and makes great low end and pretty good midrange. It also gives you the best chance of avoiding PTV issues. That cam will probably surprise you with a set of heads that can move air. On that motor, those E6 heads run out of steam before the cam does.

 

[86bluecobra]

19's with adjustable fuel pressure regulator.

If you decide to add boost then larger injectors will be needed.

On a side note: Keep running the 86 cam... It's no slouch, it's sounds great, and makes great low end and pretty good midrange. It also gives you the best chance of avoiding PTV issues. That cam will probably surprise you with a set of heads that can move air. On that motor, those E6 heads run out of steam before the cam does.

That kinda makes sense to me. The only thing is that I am going to have the engine tore down and to not change the cam just seems wrong.

I'll have to change the timing chain and It's just so tempting but I know there is already going to be issues with Piston Valve clearence so the stock cam may just stay. Thx

As far as the injectors go I may keep the stock because I think in the future a MAF conversion should be done and I'll buy injectors with the MAF.

 

[Noobz347]

That kinda makes sense to me. The only thing is that I am going to have the engine tore down and to not change the cam just seems wrong.

I'll have to change the timing chain and It's just so tempting but I know there is already going to be issues with Piston Valve clearence so the stock cam may just stay. Thx

As far as the injectors go I may keep the stock because I think in the future a MAF conversion should be done and I'll buy injectors with the MAF.

What do you mean by "tore down"? How far down? I mean... just timing cover and chain? Is the motor coming out of the car?

If you're doing all that, why not swap pistons? New bearings, reuse the rods and crank.

 

[86bluecobra]

What do you mean by "tore down"? How far down? I mean... just timing cover and chain? Is the motor coming out of the car?

If you're doing all that, why not swap pistons? New bearings, reuse the rods and crank.

I have been thinking about that but.... my wife would not appreciate me spending the money to completely rebuild the motor. It might come to that since I do think thats the way I should go.

 

[NIKwoaC]

I'd buy a nicer set of TW heads before I would dump any money into the bottom end. Good TW heads + mild cam = good power with no need for pooping away money on pistons/bore/hone/balance/etc.

 

[mikestang63]

You can also find a good used 87-93 motor for a few hundred bucks and swap out the E7's for those Holley heads and the rest of the top end you have. Maybe freshen it up with a new rear main seal and VC gaskets for cheap insurance. Then you have the correct pistons and can sell the 86 motor ,e7's, and the parts off the junkyard motor you don't need for about the same money as tearing down the 86 motor. Who knows what you will find once you open up that 86 motor. How many miles on it?

 

[86bluecobra]

That is an idea. I have a 90 block sitting in my carport. Spun bearing I think. I was thinking of taking it to a machine shop getting it fixed up then buy a 331 stroker kit and build it up. I guess just buying a 331 stroker short block would cost me about the same. Too many ideas to weigh. This is my wife's summer car and I know she doesn't want anything too crazy. That being said I like to drive it in the summer and I want something fun.

 

[Noobz347]

That is an idea. I have a 90 block sitting in my carport. Spun bearing I think. I was thinking of taking it to a machine shop getting it fixed up then buy a 331 stroker kit and build it up. I guess just buying a 331 stroker short block would cost me about the same. Too many ideas to weigh. This is my wife's summer car and I know she doesn't want anything too crazy. That being said I like to drive it in the summer and I want something fun.

I think mikestang63 has hit the nail on the head. You might also be able to find a relatively low mile explorer 302 to do the same thing to.