scramblerdude81

Alright guys i've recently got ahold of an 86 5.0 HO to drop in my car which is also an 86 i have no wiring harness for the motor or in the car, i paid 100$ for the both of them. What harness's will work with this motor? also im looking to a put a cam in it so should i go mass air? i've heard some good and bad things about the factory heads does anyone have any insite on this topic?

capri debris

The heads suck *** and because the '86 has true flat top pistons you have to be careful when it comes to P to V clearance. Some have installed E7 heads with no interference while others have had the pistons hit... the best explanation to this is that the tolerances when Ford was building these engines was different from one to the next.

If you plan on going more aggressive with the cam, don't even think about putting a set of E7s on there or you WILL be hitting.... same goes for 1.7 rockers. Only certain stock '86 bottom ends can get away with E7s... and even that is a hit or miss deal. You could go through all the trouble to put some E7s on and find out your engine isn't one that can get away with it.

The only other head choice out there for an '86 with flat tops is the Trick Flow Twisted Wedge heads. The valves are at an angle that they don't hit the pistons... I currently have these heads and a Trick Flow stage 1 cam on my '86 with no problems.

And yes, you must convert to mass air if you change cams or heads on these engines.

As far as the harnesses, any year that came with mass air (since you have to upgrade) will work on your car. Just be certain you get it all as a package... you'll need the proper ECU for either a stick or an auto and matching O2 harness. If you start mixing and matching and don't know what you're doing, you'll fry the sig return pin out on the ECU circuit board.

scramblerdude81

Ok thanks for the harness answer. Now, can I put the valve relief pistons in it or the recessed ones? And what is the downfall of the 86 heads? So your pretty much saying not to cam it or I'll throw a valve threw a piston? Would this still be an issue if I put the valve relief pistons in?

scramblerdude81

Also is there a way to tell if it really is an 86? And an HO? I've got it tore Down it had a roller cam and lifters in it and the intake said HO on it ad I have flat top pistons

capri debris

The downfall of the '86 E6 heads is that they have small valves and small intake and exhaust ports. Many consider them boat anchors if you want to make good power.

The flat top pistons are the other big downfall of the '86 engine because you can't do anything that will put the valves any closer to the pistons than they already are... like going from 1.6 to 1.7 rockers, bigger cam or better heads.

If you replace the flat top pistons with ones that have relief cuts, you can pretty much install any head, cam or rockers that you want.

Like I said before, you can change the pistons and do anything you want or you can order the Trick Flow Track Heat top end kit like I did for one of my '86 Capris. It comes with Twisted Wedge heads (that will work with the flat tops), stage one cam, roller rockers, upper an lower intake, roller timing set and push rods. If you install this kit and add a 70mm throttle body, convert to mass air and use a 75mm mass air meter, 24lb injectors, and 190lph fuel pump... you'll be guaranteed 360 hp at the flywheel.

This kit was designed to work best with flat top piston engines, but is a little pricey at $2400. You can change your pistons and assemble your own set up, but you may end up spending just as much by the time you get all the stuff you need or you can go with the kit and have everything you need in one simple package that is designed to work together and takes all the guesswork out of putting a strong engine together.

Hope this had helped you out.

scramblerdude81

Awesome. So I found a set of gt40p heads for cheap cheap at my local junk yard, are these going to need different push rods?, special headers?, head bolts?, intake?