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25+mpg 4.0l ohv build


UPDATE:

In regards to my donor "turnkey" 94 Ranger non EGR 4.0L, that had been gone over once before, ran but burned a little oil.

1) block was bored 0.5mm over, cylinder walls still look very good
2) heads disassembled; not 1 valve guide seal was seated or properly installed and all the valve guides were severly worn. This engine must have drank oil
3) the valves; stems looked new, heads were horribly caked with carbon and burnt oil, exhaust valve seats badly pitted
4) upper intake manifold gaskets both cracked
5) lower intake manifold gasket deformed and unable to properly seal
6) all pushrod ball ends worn, unusable

Currently the only choice in new 01+ Ford 4.0L SOHC replacement piston sets is from Mahle. They have an Al cast set, no skirt treatment and a CH of 1.444"; so far this is the closest to the 94 Ford OHV 4.0L's piston CH of 1.45".

It turns out that almost all aftermarket piston sets have decreased pin height to maintain the stock compression of the engine due to head milling and block decking durring rebuilding.

The Mahle set is not the cheapest but does cost as much as the Keith Black SilvOlite hypereutectic's on sale. That makes it a bit of a pill to swallow for me, though I will always take my performance goal over bragging rights so the Mahle set takes it without a second thought.

In preparation to inspect the bottom end I expect the worst and hope for the best. I will probably need to replace all the bearings and that's if I'm lucky.

On a more optimistic note, the new pistons/rod combo will liberate the crank of 35g per cylinder.
 
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i would take the mahle over crack-o-lites any day. i think your good there.



but.....cyclone. you know you wants 6 speeds mang. better mpg....cyclone.
 
Bobby:

I do not know what you mean by cyclone.

I prefer a manual transmission, I thought that I would be able to use the M5OD that the donor engine came with...2 wheel drive output.

This will never be driven like a race car, it will be driven like Granpa's farm truck; here to there, occasionally towing duty.

I never have liked automatics, I don't understand them for one. This one worked well behind the 2.9, never beat on. When the 1st torque converter died, I had it rebuilt and updated; the rebuild shop insisted that I used a their reccomended torque converter otherwise they wouldn't warranty it (though at the time, I was unaware it was a 4.0l tq converter).
 
The Ford Cyclone Engine.
 
The 3.7, 3.5, 3.3...and 3.0 ford cammers.


They are ridiculously overpowered compared to the 4.0. but huge too.

Not easy to swap.


I can't see the 4.0 ohv out doing them in any way if a guy had a high milage truck needing work. For the cost of building a 4.0....i would have to go with the cyclone.
 
Bobby, sgtsandman:

Ahhhhhh, well that sounds like extremely good advice! Thank you, there is always next time.

I take it that you've had at least one, less than desirable experience with SilvOlite pistons. I am interested in hearing about this.

My Machinist contacted me today with an update; he feels that to take full advantage of the head/intake flow improvements, that it would be a crime not to use a custom reground cam. So 1 Custom regrind is now going to happen. HOORAY!!!
 
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If you have the money and time, improving engine breathing and exhaust while it’s apart is not a bad idea at all.

If you are going to do it yourself, have someone who has done it there with you to teach you. You can over do it. If you don’t know anyone research the heck out of it before you do it. A little in the right places goes a long way.

Each engine is different and I don’t have the expertise on a 4.0 to give you pointers. Others here might.
 
sgtsandman:

While I would love to have better porting abilities. This gentleman has 35+ years, it's just not my area of expertise.

"A man's gotta know his limitations", Clint Eastwood.
 
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There is absolutely nothing wrong with that.
 
Here's an update from the Machinist; valve springs are on order, flow bench and head porting is complete. He saw an additional 20+ hp from the port work and was able to to come up with the best lift profiles for my engine and duration to be used with an automatic. I will need to hold off on the custom Cam grind for a few days but will be done by the begining of next month.

I'm shocked, the Ole 4.0L BII could see north of 30mpg (highway) with speculated efficiency improvements totally around 46%. Sometimes I have to set the bar high, just in case I make it.
 
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UPDATE:

The Porter called, all done with the intakes. In his words, "though the heads needed help the lower intake manifold was the REAL problem". That lower intake is way, way lighter!

I will snap some pics as they are truly things of beauty. I have the cam recomendations if anyone is interested; note that they are specifically for my engine with the use of an automatic transmission.

"Oregon Cam Grinding" of Vancouver Washington will be performing the grind:

0.498" @ 210° intake
0.474" @ 216° exhaust
with 112° lobe separation
(ADDITION; +4° advance)

The stock throttle body (T/B) became the next big restriction so I commissioned Mr David Endrigo, chief Machinist @ Flowtechnics of Poulsbo Wa to punch it out to 64mm.
 
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A note of interest, neither Silver Seal or Goodson still distribute the rocker arm inserts for the Ford 4.0L ohv rocker arms. The do both have very friendly, knowledgeable staff members ..)
 
tuckerdawg:

Thank you for your resopnse. I used hi lift rockers and spring delete rocker arms in my 2.9L builds with awesome results. That is why I am asking those who have used these products in the 4.0L, how it likes them. I am quickly reconsidering yet another 2.9L rebuild as there doesn't seem to be anyone who even considered it worth trying to see north of 30+ mpg from this powerplant???

I am miffed, I am begining to think that the ohv 4.0 was just the big boys making something that sucks more fuel, on purpose?

Andy D:
Thank you for yohr response .)
A note of interest, neither Silver Seal or Goodson still distribute the rocker arm inserts for the Ford 4.0L ohv rocker arms. The do both have very friendly, knowledgeable staff members ..)
Just got caught up on your build. Very curious to hear how it turns out.
 
Naddanme:

Hey Naddanme, what you driving ..)

The most current developments are these:

1) My original rockers are shot, all the companies that used to sell inserts to rebuild them have closed their doors. Fortunately for anyone who wants a better than stock option, Delta Cam of Tacoma Wa offers the rebuild of sent cores for a modest $135.00 plus shipping (both directions). What they provide is reshaping/heat treating the stem side and installing "The Fabled rocker inserts of past lore". A new stock set goes for $15/rocker plus shipping both ways, no brainier there.

2) Oregon Cam Grinders of Vancouver Wa offers regrind services, so to recut my stock cam will be $159* (correction to price for hydraulic roller cam) plus shipping both ways (price as of OCT23, $219 for custom reground roller cam).

3) I finally got around to weighing my Ford OGA series lightweight rods, 01 OHC 4.0L Mahle pistons/pins. The rods are all very close balancing them will be easy plus adding the ARP fasteners are a winning solution. The Mahle Piston set, on the other hand, came in at very dissapointing weight range; no surprise as I had to purchase 2 sets of Pistons to be able to balance them for the 2.9L's too. Oh well, it will be worth it in the end. The Mahle piston pins and ring sets were a spot on as balanced sets.

4) The custom adjustable push rods from Smith Brothers will cost just under $11 each but perhaps the best money so far as the will allow me to properly set the lifter preload. This will result in proper lifter operation, fully optimised performance and adjustability as the top end components wear. Translation, better fuel economy the Hallmark of quiet OHV 4.0L top end.

5) Having the stock T/B punched out by Flowtechnics of Poulsbo Wa to 64mm was also money well spent. BBK can eat a donut! ☕☕☕🚬

As the end becomes visible, I have no doubt if 28mpg highway with 22-24 in town but I truly hope to cross over into the 30's. That will just make going to the fuel Depot, with a 1k highway miles between fill ups, more fun (I rounded it up🙄).

I wish this engine were going into an manual Explorer Sport instead. Reading the fuel economy rants on the 2020 Explorer with 28 combined mpg claims, sure would be satisfying for a discontinued 94/95 2 door Explorer to have superior performance, gas mileage wise.
 
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I just picked up a 95 Ranger. 4.0 manual standard cab stepside 132K. My first one. Just getting ready to do a off-roader build that I can still DD. Probably won’t bust open the motor anytime soon but I enjoy following your thinking. Can’t wait to see how it turns out.
 

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