'99 ohv 4.0 cam build

[QueenCitySleeper]

yea I have the 422 cam, 988 springs, and 5.550 smithbros pushrods. the 95tm heads are a direct fit? And I thought the 98tm have different exhaust ports that work better with the cats in the y-pipe. Im just a little skeptical about going backwards.

 

[jd4242]

yea I have the 422 cam, 988 springs, and 5.500 smithbros pushrods. the 95tm heads are a direct fit? And I thought the 98tm have different exhaust ports that work better with the cats in the y-pipe. Im just a little skeptical about going backwards.

If your going to use SI valve and dual springs,i assume your doing the 422cam also.just use engine quest 95tm heads,same heads as the 98tm(what you have) but the ports are larger and flow better.they can affect your emissions but the 422 cam will allready do that.i wouldny even waste money on porting them unless you really want to.also just about the best price around for heads
http://www.ebay.com/itm/FORD-EXPLOR...Parts_Accessories&vxp=mtr&hash=item27aca4d2da

They are direct fit "same head as the 98tm but with bigger ports"and your questions were answered in last post

 

[jd4242]

Also what do you think your be doing by porting out a set of 98tm? Making the ports larger..witch is all ready done to 95tms so would save you money and why i said i wouldnt even port them unless you really want to.

 

[QueenCitySleeper]

Gotcha, the 95tm are the way to go and that price makes me smile. Thanks a lot

I found this thread very useful on the topic of heads
http://www.explorerforum.com/forums/showthread.php?t=216161

 

[jd4242]

Gotcha, the 95tm are the way to go and that price makes me smile. Thanks a lot

I found this thread very useful on the topic of heads
http://www.explorerforum.com/forums/showthread.php?t=216161

Lol wow that was about 4 years ago yea that when i was trying to find the true 95tm heads.some info is incorrect in that thread tho,ive done ALOT of r&d sense then lol

 

[jd4242]

Here on the 2nd page your see some pics of the 95tm and 90tm differences.98tms have the same cast marks and basic port profile but smaller as you see in the other thread.i still run those 95tm from EQ but some changes have been made to them sense then:shifty_ey:shifty_ey
http://www.explorerforum.com/forums/showthread.php?t=235660&page=2

 

[jd4242]

Gotcha, the 95tm are the way to go and that price makes me smile. Thanks a lot

I found this thread very useful on the topic of heads
http://www.explorerforum.com/forums/showthread.php?t=216161

Lol wow that was about 4 years ago yea that when i was trying to find the true 95tm heads.some info is incorrect in that thread tho,ive done ALOT of r&d sense then lol

 

[Dono]

Go with the bear head JD suggested. One of the main reasons I didnt is that they wont ship to Canada.
Also, I didnt go with the 422 cam, so I still have stock springs.

The right way to go is to not go pre built heads anyway. I found that even with pre built heads its best to have them vaccum checked at a machine shop to be sure the valves are sealing.

Make sure you do the same before instaling your heads. Its cheap for a machine shop to do, and its not only about valve lift, but also valve seal on the compression stroke.

for whatever reason, my valves were not seating to the head. Id hate you having to pull your heads again, like I did.

I am happy with my motor, and it has way more low rpm torque than it has in its whole life.

 

[QueenCitySleeper]

So if I go with the 95tm heads like Im planning on, wont my '99 exhaust manifolds restrict airflow since the 95tm heads have larger exhaust ports? If so I don't see why I could not do some cutting on them to make them flow well with the 95tm heads. Im just curious if this could be a possible issue as well as whether or not I will need older style exhaust manifold gaskets

 

[jd4242]

I honestly dont know.most aftermarket gaskets are much larger than needed to begine with.the manifolds normally flow way more than what the head puts out,why headers normally dont gain you power till major mods,witch i would consider getting them with these mods.i personally think you are thinking way to much into it and sounds like your looking for a reason not to use them so go with whatever you feel most comfortable with

 

[Dono]

My opinion is that there is always going to be a restriction somewhere.

Id say, if you have the time, energy, and tools, port match the exit of the exhaust port to the exhaust gasket, and do the same with the exhaust manifold.

A School of thought is to make sure the exit of the exhaust on the head is slightly smaller than the intake on the beginning of the exhaust manifold. Did I say that right?

The idea is that any turbulance wont back flow in to the head with a bit of a ridge.

There is no question that the heads JD is suggesting is the best route to go. Once you get them, you can look at the exhaust gaskets and see if there are any modifications you want to make.

I'd love for JD and I to get dyno'd before our Forced induction setups go on, just to see where our power is.

JD will def. have more top end, and probably mid range power, but I'd ownder where low is (up to around 2000 rpm). It would be great to see if he has me thru the whole powerband or not.

Were not going to find out though. JD'd trucks apart, and mine will be also tomorrow. My truck was far too reliable over the winter. Time to screw with it some more.

 

[jd4242]

98% of the time the manifolds out flow the head for the ohv.if you have your heads off just go measure your manifolds and see,the heads ports for 95tms are 1.7",98tm is 1.4.i dont see any different part numbers for difference in 95&98tms as far as gaskets or manifolds.

 

[Dono]

Exactly JD! There will be that "lip" that Ive read is required with any head thats used.

 

[jd4242]

My opinion is that there is always going to be a restriction somewhere.

Id say, if you have the time, energy, and tools, port match the exit of the exhaust port to the exhaust gasket, and do the same with the exhaust manifold.

A School of thought is to make sure the exit of the exhaust on the head is slightly smaller than the intake on the beginning of the exhaust manifold. Did I say that right?

The idea is that any turbulance wont back flow in to the head with a bit of a ridge.

There is no question that the heads JD is suggesting is the best route to go. Once you get them, you can look at the exhaust gaskets and see if there are any modifications you want to make.

I'd love for JD and I to get dyno'd before our Forced induction setups go on, just to see where our power is.

JD will def. have more top end, and probably mid range power, but I'd ownder where low is (up to around 2000 rpm). It would be great to see if he has me thru the whole powerband or not.

Were not going to find out though. JD'd trucks apart, and mine will be also tomorrow. My truck was far too reliable over the winter. Time to screw with it some more.

Just by the compression stand point alone, i should make 10% more than you anywhere in the rpm range thats not counting larger cam,tb,exhaust and extensive port work

 

[Dono]

hahahaha......ya, you have a lot of work in to that motor. Not to mention balancing of pistons, etc.

 

[jd4242]

Exactly JD! There will be that "lip" that Ive read is required with any head thats used.

I personally dont remember what the manifold port size is,ill measure tomorrow. But its also about the transition,meaning if its a square lip or ramp/smooth lip.there is alot that comes into play when you start talking about exhaust, more to it than just size.

 

[jd4242]

hahahaha......ya, you have a lot of work in to that motor. Not to mention balancing of pistons, etc.

:shifty_ey:shifty_ey

 

[QueenCitySleeper]

Ive already ordered the 95tm heads JD suggested. I was thinking exactly what Dono mentioned about port matching the manifolds. A die grinder and a carbide bur will solve any issues.

 

[QueenCitySleeper]

I am wondering if Im going to need different valve spring retainers for the 988 springs? There is obviously more to it than just the valves. getting ready to order the SI valves, so is there anything else that is recommended I order from SI? I want to try and get it all in one order

 

[jd4242]

Stock retainers are fine