1991 performance heads

[original91]

Anyone have a recommendation for aftermarket heads for the gutless engine in the Explorer to increase horsepower...aluminum or otherwise?MIne has been rebuilt and should have looked into it then but if that's all you have to do and they bolt on, it would be worth it. Do later model 4.0's have bigger valves and will those work, like the 351 windsor heads on a 302?

Thanks

 

[Spdrcer34]

95TM heads on a early block will bump the compression. That is about all you are going to be able to do.

No such thing as Aluminum Heads for the our 60* V6 motors....that I have seen.

Ryan

 

[dansnyder22]

i would say port and polish some 95tm heads and a valve job. but super six motorsports does offer aftermarket heads for the 4.0 OHV engine. but still cast iron
http://www.supersixmotorsports.com/

 

[Spdrcer34]

They aren't aftermarket heads in the way that he is looking for. They ARE an aftermarket casting though. All that was done was they were made a little thicker around the exhaust valve, as that is where the OEM castings were always cracking.

All they are doing is porting a set of those heads, and you have to buy them a new set to replace the ones they just ported for you....exactly like a Core Charge at the autoparts store.

Ryan

 

[jd4242]

they do make bigger valves for the heads,go with these heads and have them machined for bigger valves and p+p.here is a thread about the valves
http://www.explorerforum.com/forums/showthread.php?t=239196
95tm
http://cgi.ebay.com/ebaymotors/ws/e...0296227417&sspagename=STRK:MEWAX:IT&viewitem=

 

[original91]

Thanks for the responses. Spicer especially as it seems it's old school for this OHV engine. The prices for the heads from supersixmotorsports was $1700...ah er I paid $1875 for the whole engine(long block rebuilt with a 3 year unlimited mileage warranty from ATX motors here is California)...How bout just gettin a 95 engine next time with the better heads? Or does that open all kinds of cans of worms(computer etc.)

 

[jd4242]

just put the 95tm heads on the block you have they are a direct bolt on

 

[original91]

Sounds good Thanks

 

[Flip4ford]

Is 95 tm a casting number or a model year (as in will all 95's have 95tm heads??) Sorry I'm more of a body man then an engine guy. But I would like to keep a lookout for improvement mods.

 

[Ronin8002]

I believe 95TM is a casting number but it also refers to the year the heads were made for. 90TM, 91TM, 95TM, and 98TM I think. 90TM and 91TM are the same pretty much and were made for the 1991-1994 models. 95TM and 98TM are made for the 95 and up engines....basically the difference from the 90TM and 91TM is that the combustion chamber is a lot smaller on the 95TM/98TM. Also 98TM had a smaller exhaust port hole that was supposed to be better for emissions (but it limits power potential)

Now just because 90/91TM and 95/98TM are made for different years doesn't mean they won't work on other motors. They will. In 1995 Ford decided to make the "dish" on the 4.0 pistons larger than it was in 1991-1994. This meant that the compression ratio of the engine would go down unless they tightened up the space somewhere else...so they made the combustion chambers smaller in the 1995 heads.

What this means if you put the 95/98TM heads on a 1991-1994 motor is that your compression ratio will be increased to about 10:1 (9:1 stock). Might mean you have to run a higher grade of gas too if you get knocking but you'll get more power and possibly better mileage. Likewise if you put 90/91TM heads on a 1995 motor, it would drop your compression ratio down to 8:1...which would make your truck more of a slug than it already is

If you swap heads you might as well find a place to port them also...you will be happy with the result. Swapping to a 410 cam would also be a nice change and this would be much easier to do while the heads are off also.

All in all a set of 95TM heads + a cam swap would be around $600.00 and give you a nice bump in power. Porting would cost extra but would be worth it in my opinion.

 

[jd4242]

yea what he saidbut be careful when getting 95tm heads many people advertise them as 95tm/98tm those are not true 95tm heads,the link i posted is the only place ive found that sell new new cast true 95tm heads, the ones with the big ports!!

 

[Flip4ford]

Well Cool Thanks guys- I'll keep a look out for a set