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91 4.0 rebuild


gaz

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Location
Wa, Bremerton 98310
Vehicle Year
1987
Make / Model
Ford
Engine Size
87Ranger Endrigo 2.9l, 87BII Endrigo 4.0l
2WD / 4WD
4WD
Total Lift
Ranger 5" (1½" Hiryder/3" body), BII 4" Procomp
Total Drop
Ranger 5sp, BII A4LD
Tire Size
Ranger 32"/4:10LS, BII 33"/3:73LS
My credo
Deengineer until it is how Blue Oval should have sold it!!
@kdooxp
Yes, I have a JET Stage II PCM CHiP for my rebuilt 2.9l when used with an automatic transmission. for EEC-IV, there is no onboard tuning or data function like with OBD2 in EEC-IV.

I have both 2.9l and OHV 4.0l with JET and Hypertech PCM CHiPs; they do not do a ton but if the engine was well built, has a good exhaust and ignition, they perform like a cherry on an ice cream sunday...they provide just that little extra bit.

It you want data mapping+, you need to invest in the EEC-V system. I like how the EEC-IV responds to engine improvements. I haven't done anything yet that it doesn't handle well ..)

I believe that you will have a difficult time finding anything but 98+ replacement heads. Like I mentioned, I was lucky and have not the ad to buy valves yet; they do not cost much.

BORED T/B
YES, the body is disassembled, then it's body is bored out to the new dimention and a new throttle plate is built to fit the new bore. My good friend Mr. David Endrigo CEO Flowtechnics of Poulsbo Wa has made them for me using stock Ford t/bs. He only bites them to 64mm as the sidewalk is getting pretty thin...I believe that he is correct and 66mm is too thin. He also tapers the inlet and reworks the throttle plate hinge.

HEADERS
I am using 2.9l JBA's on my OHV 4.0l with 98+ spec heads; the exhaust ports are much smaller than the 91-97 heads and actually about the same size as the 2.9l's. I had Mr. Endrigo port them to the 2.9l headers, I believe this is the best move that you could make.

Last I looked, if you are willing to write the check, new old stock JBA and Borla headers are still available for 2.9 and 4.0. Using the 2.9l version with the 98+ heads will give you more exhaust port velocity...you could also make it commission a custom set; I know that Mr. Endrigo would be happy to help with that too.

The "on the cheap" solution for improved design and a little better flow is to use a set of 98+ stock Ford exhaust manifolds. They were redesigned and do offer improved flow, not on par with headers but better than either the 2.9l or 91-97 OHV 4.0l had.

I have not done anything with OHV 4.0l Mustang exhaust components.

VALVE TRAIN
I am using adjustable 2.9l rockers with custom length Smith Brothers rods in my 4.0l to resolve the non adjustable situation. They are not a drop in; 6 of them line up perfect, 6 of them need a small bit taken away to line up. It could be done by anyone however, soliciting the assistance of a reputable machinist is a prudent move.

My primary motivation for chosing this route is to keep these expensive roller lifters worker as long as possible...and I had an extra set of increased lift 2.9l rockers in my spare parts bin.
 
Last edited:


kdooxp

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Location
South Dakota
Vehicle Year
1991
Make / Model
Ford Ranger
Engine Type
4.0 V6
Transmission
Automatic
2WD / 4WD
4WD
Tire Size
31”
Okay, thank you.
I’m not sure I want to spend $1500+ for just headers but I’ll keep digging maybe I can find some. I have seen a few sets of headman headers that might work, but I’m sure the quality isn’t the same.

I believe if I order 5.550 inch pushrods they should work with the increased lift and the stock replacement Melling rocker arms I have, but I’m going to wait and use a pushrod length checker to be certain.
 

JoshT

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4WD
VALVES
I do not know what you mean by 2 piece valves.
Two piece is kind of misleading as the install and (hopefully) remove as a single piece. Valve head and stem are different materials and pressed/welded together. They were not uncommon in the past, I don't know about now.

• consider adjustable push rods; changing all of your valve train components leaves your non adjustable valve train likely out of speck. The simplest solution is a set of adjustable push today (Smith Brothers makes them)
Adjustable pushrods? Who came up with that genius idea.

Those "adjustable pushrods" are measuring tools, do not run them in place of a normal push rod. Use one to check the length you need to order, then order a custom set in the proper length.

Sorry Gaz, but that right there is enough to make me question the rest.

I’m also having trouble finding headers that are a guaranteed fit. There’s a lot that advertise they fit on mustangs with the 4.0 but not the rangers.
Those would be SOHC headers, not going to work.

Looks like JBA still offers a header and y-pipe set for 95-97 Ranger 4.0L. The chassis and suspension are practically the same as a 91, so those might work.
 

kdooxp

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1991
Make / Model
Ford Ranger
Engine Type
4.0 V6
Transmission
Automatic
2WD / 4WD
4WD
Tire Size
31”
My Harley has adjustable pushrods. I believe they are available for most applications, and they work fine as long as you order them to be used as pushrods and not just to check length. I would prefer to have solid pushrods.

“Looks like JBA still offers a header and y-pipe set for 95-97 Ranger 4.0L. The chassis and suspension are practically the same as a 91, so those might work.”

Awesome I’ll check it out.
 

JoshT

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2WD / 4WD
4WD
My Harley has adjustable pushrods. I believe they are available for most applications, and they work fine as long as you order them to be used as pushrods and not just to check length. I would prefer to have solid pushrods.

“Looks like JBA still offers a header and y-pipe set for 95-97 Ranger 4.0L. The chassis and suspension are practically the same as a 91, so those might work.”

Awesome I’ll check it out.
Your Harley was designed that way and is a very different engine design and application. Among other things, the pushrods on the Harley are in tubes in the outside of the engine.
 

gaz

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U.S. Military - Veteran
Joined
Sep 21, 2007
Messages
1,499
Reaction score
706
Points
113
Location
Wa, Bremerton 98310
Vehicle Year
1987
Make / Model
Ford
Engine Size
87Ranger Endrigo 2.9l, 87BII Endrigo 4.0l
2WD / 4WD
4WD
Total Lift
Ranger 5" (1½" Hiryder/3" body), BII 4" Procomp
Total Drop
Ranger 5sp, BII A4LD
Tire Size
Ranger 32"/4:10LS, BII 33"/3:73LS
My credo
Deengineer until it is how Blue Oval should have sold it!!
@JoshT

Sorry joshT, but I will not be reading your guff in the future 😭

You do not need to question anything, just take a couple years to learn to read, theng go to Smith Brothers website and try your new skill.

Explanation for the "attached" pictures, both directly off the Smith Brothers site:
• one is Pushrod length measuring kit (sounds like you've heard of these).
• the other is a custom set of ADJUSTABLE pushrods...go figure

FYI
I don't go around talking about crap I haven't already done, tried myself or thoroughly looked into...if I can't explain something, I keep my trap shut. Your welcome.
 

Attachments

SenorNoob

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Middle Tennessee
Vehicle Year
1988
Make / Model
Ford
Engine Type
4.0 V6
Engine Size
4.0
Transmission
Manual
2WD / 4WD
4WD
Total Lift
1.5" Front + 4" Rear
Tire Size
245-70-R16
As far as exhaust is concerned. I have a pair of 95 Explorer manifolds mated to a stock replacement 88 2.9 Y-Pipe. I doubt it gets much farther apart than that without problems.
 

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