Extrudehone or other tweaks for 4.0

[Rustydawg]

Hey guys, first post here. I've got a '92 Supercab 5-spd with a 4.0 that's getting tired.

I'm thinking of pulling the top end off and freshening a few things up, a good valve job and cleaning up the ports a bit.

From what I've read the lower intake doesn't really respond to porting like the 5.0 can use.

Anyone had any luck with the Extrudehone process? Sounds like it is worth looking into. Interested in any head porting tips too if any of you folk have been there.

I haven't touched the engine internally, just some airbox mods and cold air ducting, and Borla SS headers & catback - that it really liked!

Later
Russ.

 

[wahlstrom1]

How far are you willing to go into the engine past a valve job? I know a guy in calgary that has a few 4.0Ls lyin around, and several build parts, like cam's/piston's/valve springs etc. If that sounds like something you might wanna look into lemme know and I'll get you his contact info.

-andrew

 

[Rustydawg]

Andrew

I'm hoping to keep it pretty simple and avoid pulling the engine - I can't really deal with the down time and my kids keep my too busy to give me much wrenching time.

I haven't even done a compression test on it, my gauge won't reach down into the spark plug threads... It's got 255 000 Km on it and runs OK, no valvetrain noise yet (fingers crossed) it just used to have so much more jam.

I've always hoped that there's more power to be had with a little 'massaging' of the intakes, heads etc and a good valve job.

 

[Yellowsplash]

Extrude Honing the intake would be a good idea as it just polishes the areas where the airflow normally meets resistance. You just dont want to "hog" out the runners like most people think needs done...bigger isnt always better. The light polishing can help take the casting burrs out and help velocity out. The only downside is extrude honing can get alil pricey. I havent looked into it for the ranger though.

 

[woodyedmiston]

Take a look at these four threads:
http://www.therangerstation.com/forums/showthread.php?t=25719&highlight=heads
http://www.therangerstation.com/forums/showthread.php?t=25532&highlight=heads
http://www.therangerstation.com/forums/showthread.php?t=25632&highlight=heads
http://www.therangerstation.com/forums/showthread.php?t=25009&highlight=heads

They look the same but they are not.

 

[Rustydawg]

I had previously read the post by Doug904, some good general info. He talks about aftermarket heads (stock type replacements, I can only assume).

Has anyone had their hands on these, I'm curious to hear who's making them?

 

[rangerT]

How far are you willing to go into the engine past a valve job? I know a guy in calgary that has a few 4.0Ls lyin around, and several build parts, like cam's/piston's/valve springs etc. If that sounds like something you might wanna look into lemme know and I'll get you his contact info.

-andrew

hmmmm....if rusty doesn't want those parts i may be interested in some as i have a 00' 4.0 that is slowly starting to tick away(may be lifters/pushrods or maybe even lower yet).....i am just one province over(the new oil prov.)

thanks
Trevor

 

[Rustydawg]

Trevor in Sask, The parts are all yours. I don't intend to get too far into it. Heck, I may never crack the heads off, it still runs fine just slower than I remember. Or is everyone else going faster? Hmmmmm....

 

[turbo cat]

King cylinder head has bare NEW castings and has them fully assembled that will run you about 400$ for the pair. You can clean up and smooth out the intake yourself. The lower will be super easy too do but dont expect much power to be gained the only restriction for a NA 4.0 ohv is the TB. If the compression is good and the valvetrain isnt making noises I would strongly sugest not tearing into it (if it aint broke dont fix it) with a valve job and port work your hardly going to notice anything. A TB and a good exhaust if you dont have one would be a good start. You could put a cam in but youll have to strip alot down and upgrade the springs....

 

[Rustydawg]

Turbo Cat, I wouldn't entertain the idea of a camshaft unless I was yanking the engine out and going through the whole works.

Personally I think the throttle body is a poor performer per dollar spent. I quizzed a 4.0 Litre speed parts merchant and they downplayed the throttle body, saying it offered increased throttle response due to it's larger size, that's it. Of course he'd still sell me one...

Take a look at a Holley 600 cfm carb which would realistically support 400 HP of air. Area of the four throttles alone (excluding the restriction of venturis & boosters) is equivalent to a single 80 mm throttle. A throttle half that area would be 57 mm, supporting say 200 HP. Considering that my '92 was factory rated at 145 HP and it still has to pull air through the MAF, the factory throttle body doesn't look so bad.

Engines with low valve lift benefit from a good multi-angle valve job. From the factory my engine offers 0.6 HP per cubic inch, any kind of breathing improvements will be noticeable.

 

[turbo cat]

actually a larger TB can actually kill throttle response (depending on the size) too large of a Tb could kill velocity. But i agree on the dollar for power spent the Tb is a waste of $$$$ in my 02.

 

[slimchriz]

Yah Bigger is not always better for N/A motors I ported and polished my entire system from TB to Turbo housing on my audi and idle was much rougher and response was slower although with the turbo its worth it to increase flow and lessen spikes...

I would clean up intake if you want to there is much improvement to be made over the rough cast surfaces left inside most stock intakes