1986 5.0 SEFI vs 5.0 H.O. Differences

[86lx]

What are the key differences between the SEFI and HO versions of the 5.0 for the 86 model year?

We are picking up an 86 cougar that will be donating it’s drivetrain for the 86 LX “project” we have going and I’m wondering what we are looking at to bring performance up to H.O. standards.

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[FoxChassis]

For 1986 model year only the only difference between H.O. and S.O. in the long block is the cam.

[gmatt]

Firing order? Goes with the cam.

Which got me thinking: were the S.O. engines roller cam/lifters?

[Haystack]

All 86 cars and newer were roller cams. Upper intake is smaller, lower intake is the same. Exhaust manifolds instead of headers, 14# fuel injectors instead of 19# injectors. Single roller instead of dual roller timing chain. 86 only had "flat top" dished pistons which were the same as an 86 gt motor, as well as e6se heads.

Personally I'd build the cougar over the mustang, but that's just me.

[Haystack]

Oh, the rear end in the cougar is wider, and a 7.5" rear, the driveshaft is longer, the rear control arms are different and so is the k-member, and motor mounts.

[OX1]

86 non HO pistons were forged?

[Haystack]

https://www.coolcats.net/modifying/ho_transplant.html

This tells you a pretty complete difference between the engines. I have heard that the 85 and newer Mustangs are always forged pistons. I have also heard that the standard output motors have the same Pistons as the 86 Mustang GT, but people usually say that they are cast aluminum. I honestly can't remember I knew at one point

[OX1]

I know mine are forged. Pretty sure non HO's never were, or at least cast
until the went to hypers.

The forged piston part numbers are:
1985: E4ZE-6110-SB
1986: E6ZE-6110-BA
1987-92: E7ZA-6110-CA

These are mine........

[ZephyrEFI]

Personally I'd build the cougar over the mustang, but that's just me.

Me too!

[erratic50]

Remember — firing order is both a cam thing and an ECU tune thing. If you run a standard 302 with and HO computer you have to repin at the ECU or the sale and pepper shakers so the injectors fire in the correct order. Otherwise you will spray fuel on a closed intake valve and it will run like ****

[86frankenstang]

Me too!

The Cougar we just picked up is in rough shape structurally.

[mustang4life1985]

All 86 cars and newer were roller cams. Upper intake is smaller, lower intake is the same. Exhaust manifolds instead of headers, 14# fuel injectors instead of 19# injectors. Single roller instead of dual roller timing chain. 86 only had "flat top" dished pistons which were the same as an 86 gt motor, as well as e6se heads.

Personally I'd build the cougar over the mustang, but that's just me.

Thanks for this info. I was wondering about this as I'm looking for a roller cam 302 HO for my 83GT. I'm going to go with a 87-92 motor vs the 86.

[Haystack]

Remember — firing order is both a cam thing and an ECU tune thing. If you run a standard 302 with and HO computer you have to repin at the ECU or the sale and pepper shakers so the injectors fire in the correct order. Otherwise you will spray fuel on a closed intake valve and it will run like ****

I wouldn't rewire injectors... On the s.o. firing order 7 and 8 fire right after each other. If you repin the connector for a cam swap, it would still be expecting this. Not sure how accurate the o2 sensors really are, but I would think this would mess with it after the firing order change.