'99 ohv 4.0 cam build

[QueenCitySleeper]

first gen OHV pistons right? They have a shallower dish to them? and there wouldnt be any clearance issues?

 

[jd4242]

first gen OHV pistons right? They have a shallower dish to them? and there wouldnt be any clearance issues?

You have a ohv right? Yes first gen piston are less dished than 95+,sohc pistons are flat.

 

[QueenCitySleeper]

yes its a '99 ohv. I think the higher compression would nicely compliment a 91 octane tune. Have you had any troubles with your higher compression?

 

[Dono]

Im soooo jealous. The higher compression will work great with the 422 cam.

 

[jd4242]

yes its a '99 ohv. I think the higher compression would nicely compliment a 91 octane tune. Have you had any troubles with your higher compression?

Ive had no problems and i run around 10.6:1.dont think it will be a neck breaking mod tho,yes with higher compression and 422 cam you wil definitely feel it but not like you added a couple hundred horsepower. The high compression make everything work better and more efficient together.

 

[masospaghetti]

the guy i sold mine to is getting avg 4mpg better

I don't believe this, a 25-30% increase in fuel economy from an underdrive pulley? There's no way your accessories are pulling that much power.

For example, it takes approx. 50 hp to drive down the highway at 70 mph. To get 25% improvement, you'd have to reduce that to 37.5 hp at cruise. Since the underdrive pulley is reducing the accessory speed by around 25%, that means the 12.5 hp gained must have come from slowing down the accessories by this 20%.

In other words, before the underdrive pulley, the accessories would have been pulling 60 hp. There's no way the accessories pull anywhere near that kind of power. A 105 amp alternator pulls, at most, 1.5 kw or about 2 hp. The a/c pump pulls the most, about 10-15 hp at max load. This is just an example with rough numbers, but you get the idea.

 

[jd4242]

I don't believe this, a 25-30% increase in fuel economy from an underdrive pulley? There's no way your accessories are pulling that much power.

For example, it takes approx. 50 hp to drive down the highway at 70 mph. To get 25% improvement, you'd have to reduce that to 37.5 hp at cruise. Since the underdrive pulley is reducing the accessory speed by around 25%, that means the 12.5 hp gained must have come from slowing down the accessories by this 20%.

In other words, before the underdrive pulley, the accessories would have been pulling 60 hp. There's no way the accessories pull anywhere near that kind of power. A 105 amp alternator pulls, at most, 1.5 kw or about 2 hp. The a/c pump pulls the most, about 10-15 hp at max load. This is just an example with rough numbers, but you get the idea.

You can belive whatever you want to believe.i gained some and many others have to. Ive gained all most a 100 hp on my motor so should my mpg have increased?

 

[masospaghetti]

You can belive whatever you want to believe.i gained some and many others have to. Ive gained all most a 100 hp on my motor so should my mpg have increased?

Unless i'm missing something fundamental here, the math just doesn't work - gaining 4 mpg is not possible. Your accessories just don't draw that much power to begin with!

You're right, I can believe whatever I want. But I'm posting this because a forum should be spreading accurate information.

 

[jd4242]

Unless i'm missing something fundamental here, the math just doesn't work - gaining 4 mpg is not possible. Your accessories just don't draw that much power to begin with!

You're right, I can believe whatever I want. But I'm posting this because a forum should be spreading accurate information.

It is accurate info.its been proven time and time again.udp release hp and add mpg

 

[QueenCitySleeper]

ok thanks, I was pretty curious about raising the compression. But knowing my luck Id probably crack a head with high comp and dual valve springs. Ill most likely just stay stock bottom end. I bet those pins are pressed in anyway.

 

[Dono]

Update? hows that muffler sound?
Issues yet to be ironed out?

 

[QueenCitySleeper]

The heads are out getting cleaned and checked for cracks right now. I was wondering how much guys have paid to have their springs fitted to the heads? I understand that the valve guides need to be cut to accomadate the dual 988-12 springs. Comp Cam sells a tool to do this, but I have not a clue how much they need to be cut. Not sure if I feel comfortable machining valve guides anyway. Im still waiting on a few gaskets and the new slave cylinder. Not looking forward to dropping the trans.

 

[Dono]

Ya, I've never pulled a motor, so I know what you are saying. The motor will be easy to work on, but getting it out of there will be a challenge. Everyone says its really easy, and would prefer to pull a motor to work on it rather than do something like I did (Heads and cam with block in the engine bay).

Nice to hear the project is going forward. Someone will respond to your head question. I can't see it being very expensive to set up the heads for dual springs though. Are you sure you don't want to go with aftermarket castings on the heads? The factory ones always crack.

 

[QueenCitySleeper]

I was thinking about going with aftermarket castings because I read they were stronger, but do the originals after porting "always crack"? Ive made the hard decision to remain factory compression.


And btw Ive taken pictures along the way and will 100% put up nice videos as soon as the new hardware is broke in

 

[Dono]

Excellent on the videos/pics!
Factory castings just plain crack. The posts on here of guys with cracked heads are endless.
You can go aftermarket castings and remain with the same compression.

 

[QueenCitySleeper]

So I understand that the Australian castings are the ones to get? Does anyone know a reliable and reasonably priced manufacturer of new 1999 4.0 ohv cylinder heads?

 

[QueenCitySleeper]

Dono, you have the ClearWater's with SI valves. I want to run the same setup you have. So you've had no problems with your top end?

 

[jd4242]

You want fully assembled? You going to do any heavy port work?

 

[QueenCitySleeper]

I have the springs already, but haven't yet ordered the valves. Im thinking bare heads. Ill have the springs installed at a shop. And yes I'll be doing some porting

 

[jd4242]

Dono, you have the ClearWater's with SI valves. I want to run the same setup you have. So you've had no problems with your top end?

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