Questions 86 GT

pcfixeray · 10-19-2009, 01:28 AM

OK, I got this car was running rather bad so I have decided to go through the whole engine. To my surprise wow someone has done some mods to the car case even running bad it was fast but I put about 30 miles on it and started the tear down and glad I did. Valve cover bolts most you could take out by hand and same with lower intake manifold!!

So I have some questions to anyone who has modified one of these HO engines.

I am looking to get more horsepower and torque without a turbo or charger.

I have seen larger throttle bodies for the 87+ mustangs but not the 86 are they the same?

Which cam would be best I am looking at 1/4 mile and still be able to run on the street and I do love a rough idle cam they sound good to me

Should I go with a high volume oil pump? Etc

Should I stick with stock pistons and heads? Have them ported and polished? Would you recommend drilling it to make it a 4 bolt main?

Is there any reason to change injector size if I keep it naturally aspirated?

I would like to see this car get in to the low 13's if not 12's

and not to mention I am doing it on a budget almost all work will be done by me including body and paint! Will have machine shop look at block, heads and crank though to make sure they are OK

So anyone have any suggestions?

Guess I should say I am new to the Mustang 5.0's

Any help would be appreciated!

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projectresto83 · 10-19-2009, 11:25 AM

First off you from the factory you do not have the same setup as the 87-93's. If you do have a EFI system on the motor then that might raise another question, what year motor do you really have. The year can be found on the block right above the starter. 86 block starts with E6. If you do have an 86 motor I would suggest either replacing the motor with a low milage 87+ shortblock. The the flat top pistons in the 86 block are exactly ideal and since you are on a budget I don't think replacing the pistons would be an option but thats your opinion.

If you have an 86 motor then no you do not want to keep the stock heads. The 87+ heads are better but not by much. If you are really on a budget find some GT40's at least but if you have the money for aluminum heads go that way.

A 4 bolt main is not neccisary with what you want. Your block will split before you have problems with only having a 2 bolt main.

If you just want a lopey idling cam then you have no clue what you need because lope doesn't mean performance. (no offense, thats what everyone seems to wants)

Low 13's/high 12's can be achieved on a stock motor just the FYI.

Then you also need to worry about suspension, fuel system, ignition, rear end and trans items in that budget too.

86 5.0L · 10-19-2009, 01:10 PM

86 had SEFI, the same as 87+

projectresto83 · 10-19-2009, 04:40 PM

Ok, my bad I did mess that part up on the SEFI but the 86 pistons and heads still suck and need to be changed IMO.

gthokiwi · 10-19-2009, 05:38 PM

my 86 has aluminium heads from edelbrock with 2.02 valves, it also has mac shorty headers, 2.5" offroad h pipe and flowmaster 2 chambers.
it sounds fantastic and it is very very quick.
sorry i don't know what cam or pistons it has though.

pcfixeray · 10-19-2009, 06:18 PM

Thanks for the info. I know a rough idle cam doesn't mean performance but I would like to find one that has performance and a rougher idle.

The engine is a 5.0 HO SEFI has E6 heads with flat top pistons factory compression ratio was 9.2 to 1

It has the 8.8 rear end with 4 link, T-5 with 10.5" clutch (tranny has been rebuilt recently about only thing thats good other then body and most of the interior.

Stock specs:

Horsepower : 200 BHP @ 4000 RPM
Torque : 285 BHP @ 3000 RPM
3.73 Rear end

Transmission
1st 3.35 2nd 1.93 3rd 1.29 4th 1.00 5th 0.68 rev 3.15

I would like to get close to 300-350HP

I will definitely go looking for some GT40 heads I hear you can find them on some V8 explorers and trucks?

I may go the short block route cause once I pulled motor out today and broke it all down its pretty worn. Its been rebuilt in the past only cause I see that someone marked piston rods for each cylinder with number stamps and it had felpro gaskets and a lot of red rtv!!!

Cylinder bores look ok pistons had a lot of play in them!! The crank has some heavy wear on main caps and mild on connecting rods. I know it can all be machined and get over sized bearings and stuff but by the time I do that might as well get a new short block or a rebuilt one that has a warranty.

I was also wondering if I get a better fuel pump and increase fuel pressure to get more flow out of stock injectors will this increase HP?

Otherwise all great advice thanks!!

BTW does anyone know if you can put the 87 LX or GT tail lights on an 86?

gthokiwi · 10-20-2009, 12:09 AM

the 0.68 overdrive in those T5 boxes is awesome.
mine has 4.11 rear end gears and 17" wheels. it gives it an amazingly quick acceleration but then once you get up to speed, whack it in 5th and with that overdrive it cruises at about 2000rpm and gets good gas mileage.

86 5.0L · 10-20-2009, 02:47 AM

Quote:

Originally Posted by pcfixeray

Stock specs:

Horsepower : 200 BHP @ 4000 RPM
Torque : 285 BHP @ 3000 RPM
3.73 Rear end

2.73

Quote:

Originally Posted by pcfixeray

I was also wondering if I get a better fuel pump and increase fuel pressure to get more flow out of stock injectors will this increase HP?

no, but it would be a good idea if you plan big power down the road

Quote:

Originally Posted by pcfixeray

BTW does anyone know if you can put the 87 LX or GT tail lights on an 86?

yes, 83-93 are all interchangeable parts, even 79-82 fit(some parts require abit of modification)

projectresto83 · 10-20-2009, 03:48 AM

If you are looking to hit 350hp and stay NA then you will want to get something better than gt40's. Without spray or boost then you will want to look into a 331 or 347 stroker kit and a good set of aluminum heads, a really good flowing intake, and then get a custom ground cam to match.

Michael Bachman · 10-22-2009, 03:00 PM

There is another thing about the 1986 5.0 motor that is better then the 87-93, the stock 86 cam ramps up quicker. I've got J302 aluminum heads on my 306 with coated forged TRW pistons, ported tubular GT40 manifold, 1.72 roller rockers, stock 86 cam, 77mm Pro M, 70mm throttle body, full length MAC headers. It's a nice combo for open track events.

I'm looking at upgrading my 86 by going to a 10.75 to 1 331 with AFR 185 heads, RPM II intake and a custom cam.