How to build a 4.0 OHV for power, some limits and tips...

[Biggfoot44]

Intresting thread .

So all years had the same CR , but the "95 up heads have 10cc smaller chambers, the difference being in the piston dish . Presumably putting later heads on an early engine would give a compression increase ? Would this be viable/ worthwhile ?

 

[GoGoggansGo]

Intresting thread .

So all years had the same CR , but the "95 up heads have 10cc smaller chambers, the difference being in the piston dish . Presumably putting later heads on an early engine would give a compression increase ? Would this be viable/ worthwhile ?

lol i haven’t been active on here since 2012 and got bored. The short answer would be no, the OHV 4.0 wouldn’t gain a lot by doing a head swap from the later castings. Even if the compression did go up and I’m sure it does Ford must of gone it’s not worth talking or re certifying the engine over

 

[Angie]

In case any one is looking for the Upgrading V6 article. here is a media link to a pdf of mine. cheers

How-to-build-and-modify-Ford-V6-engines

MediaFire is a simple to use free service that lets you put all your photos, documents, music, and video in a single place so you can access them anywhere and share them everywhere.

www.mediafire.com

second link in case top isn't online

MediaFire

MediaFire is a simple to use free service that lets you put all your photos, documents, music, and video in a single place so you can access them anywhere and share them everywhere.

www.mediafire.com

 

[GabrielBR]

For the later model 95-up OHV's using the larger SOHC maf which is 65mm in Diameter works great.

Is it easy to find on ebay or amazon?
How about the MAF sensor, does it have the same conector?

 

[stsalvage]

Ive used Jet products and i would recomend not too. i disagree with the pistons being "weak" ive yet to break a piston. My NA 4.0 suffered from overheating that cause "the death rattle" while taking a hill. Detonation so bad it blew the gasket out in many areas, smashed the middle combustion chambers of the head sideways into the head, cracks everywhere. coolant pooring out the exhaust, cracked/chipped valves. Yet the bottom end was 100% reusable. My current 92 oem longblock was pushed with over 15psi of boost from a t3 turbocharger on a few occasions and fed with 5 psi daily. The 4.0 obtains that level of boost before 2500. It has 100% oem fuel managment and ecu drawing thru the oem maf with no 02 feedback. It allso rattled a few times under high boost. I just pulled it apart and bank 2 had a small coolant leak into #6. New headgaskets and good to go. can a cast psiton break sure they can but Ive only seen a few pics so far of failed 4.0 pistons

I've found out the pinging when you take a hill is because of Octane I ran 87 in mine at fist but it hated the 87 now I run the 89 much better less pings. I know it would run better on 91 But I'm not that rich.

 

[Dirtman]

You know what helps stop pinging? EGR valves...

 

[alwaysFlOoReD]

I didn't think the egr was engaged under wide open throttle, like going up a hill?

 

[Snoranger]

I didn't think the egr was engaged under wide open throttle, like going up a hill?

I’m pretty sure that was to bust stsalvage’s balls... hes posted at least half a dozen times that the EGR valve is the brainchild of Satan himself and should be avoided at all costs.

 

[JeffAllen]

For the later model 95-up OHV's using the larger SOHC maf which is 65mm in Diameter works great.

Is it easy to find on ebay or amazon?
How about the MAF sensor, does it have the same conector?

GabrielBR which model year trucks are you talking about using their factory 65mm MAF sensor and did they have to come from the 4.0 sohc trucks only?

 

[RhodesCD]

How much can you safely shave the heads for increasing compression?

 

[RhodesCD]

Can you by a replacement 4.0 OHV engine that is 30 over?

 

[RhodesCD]

Can you buy replacement heads with roller rockers to go with the higher performance Comps CAM?

 

[JeffAllen]

Can you buy replacement heads with roller rockers to go with the higher performance Comps CAM?

Roller rockers are non existent for the 4.0 unless you were to have them custom made. There are a few different cams comp cams sells for it. I just ordered new Promaxx 4.0 heads from Jegs.

 

[Ranger Tony]

Doug...That was an impressive write-up. I have a '91 Ranger w/4.0. I was going to do a 5.0/manual swap; but I've changed my mind and decided to rebuild my motor and do some upgrades in the process. My questions...I was thinking about rebuilding it as a stroker. The only kit I have found is from Tom Moran Engines in Canada. They want $3k for the kit and that will kill my budget if I have to spend that much. I still need heads, manual trans, bell housing, drive shaft...etc.. My objective is to build a show truck that will display some some "Occasional Go", not a full-on race truck. Could you, or anyone else reading this reply, suggest where else I might try to locate a bit more reasonably priced stroker kit for my project? Thanks in advance for any help. Tony tonyduprey@msn.com

 

[RhodesCD]

What is the Diameter of a 98 4.0L OHV MAF as compared to the SOHV's using the larger SOHC MAF which is 65mm in Diameter?

And if you were to change from a 98 4.0L OHV MAF to a newer SOHC 65mm MAF, will any other changes need to be made?