• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

1997 Ranger 4.0 OHV Rebuild question


97rangershmazda

New Member
Joined
Sep 12, 2020
Messages
7
Reaction score
0
Points
1
Location
Norcal
Vehicle Year
1994
Make / Model
Mazda B4000
Transmission
Manual
Hi, I'm new here, I have a 1994 Mazda B4000 in which I'm rebuilding a 1997 Ranger engine for. It's a 4.0 SOHC with OHV. My question is do I need to worry about where TDC is of I'm replacing both heads with brand new ones? I should just be able to turn the crank shaft until I see the pistons at TDC and put the new heads on correct? Any help is much obliged. Just was wondering before I pull these old heads off.

P.S. I have one more quick question, will the manual transmission from my 1994 B4000 4.0 OHV engine bolt up and work with this 1997 Ranger engine? Thanks so much for any help and stay safe out there in these troubling times...

Regards,
Matthew
 

Attachments



RonD

Official TRS AI
TRS Technical Advisor
Joined
Jun 2, 2012
Messages
25,290
Reaction score
8,290
Points
113
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
Welcome to TRS :)

You are working on two 4.0l OHV engines, drop the SOHC(overhead cams) that's a different engine, only 2001 and up Rangers used the 4.0l SOHC engines

You can bolt the heads to the OHV engine regardless of piston positions
All the valves will be closed until Rocker assembly is added

Yes, the 1994 manual trans will work on any 1990-2000 Ranger 4.0l engine, its an M5OD-R1(M5R1) trans it has ATF inside not gear oil, just FYI
It has 3 rubber plugs at the top back of shifter housing, they like to dry out and leak, check them

The Flywheel from the 1994 4.0l will not work on the 1997 4.0l, in 1997 Ford changed the 4.0l Crank to an 8 bolt version, 1990-1996 used 6 bolt
So if the 1997 didn't come with a flywheel you will need to buy one
Also change the rear main seal when flywheel is off


Some info on rebuilding 4.0l OHV here: https://www.therangerstation.com/tech_library/40rebuild.shtml
 
Last edited:

97rangershmazda

New Member
Joined
Sep 12, 2020
Messages
7
Reaction score
0
Points
1
Location
Norcal
Vehicle Year
1994
Make / Model
Mazda B4000
Transmission
Manual
Thanks for the reply, that some really good info and I really appreciate it. I got the heads off and I'm wondering if it's a good idea to do a leak down test, to test the rings since I already have it down this far? Any recommendations on what I should use for a leak down test? Thanks again for the info and thanks for the link.
 

Attachments

97rangershmazda

New Member
Joined
Sep 12, 2020
Messages
7
Reaction score
0
Points
1
Location
Norcal
Vehicle Year
1994
Make / Model
Mazda B4000
Transmission
Manual
Also thank you for the clarification on the OHV vs SOHC.
 

gaz

Well-Known Member
U.S. Military - Veteran
Joined
Sep 21, 2007
Messages
1,382
Reaction score
623
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" (2" suspension), BII 4" suspension
Total Drop
Ranger 5sp, BII A4LD
Tire Size
Ranger 33"/4:10LS, BII 29"/3:73LS
My credo
Deengineer until it is how Blue Oval should have sold it!!
97rangermazda:

You need to know that if you are installing 97 4.0 ohv heads on a 94 4.0 ohv bottom end you will be increasing the compression approximately 1.0 whole point; resulting in a 10:1 (ish) compression ratio engine vs the stock 9:1. You should only use premium fuel in this set up.

Also, your 97 heads may be a 98TM casting which has the smaller, more round exhaust ports. Post a pic of the 97 head exhaust ports so that you know what you'll be dealing with.

Are you doing anything with the valve train or just reusing the 94 or the 97's push rods/rockers?

I highly recommend having your valve guides measured prior to reassembly. If yours are anywhere as worn as mine were, your rebuild will drink oil and suffer on overall performance.
 

RonD

Official TRS AI
TRS Technical Advisor
Joined
Jun 2, 2012
Messages
25,290
Reaction score
8,290
Points
113
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
One heads up, you have a CAM sensor and synchro tower on the 1997, seen in 1st picture above, your 1994 computer doesn't use/need that, and the bushings on these were a know issue, more so on the 3.0l
The lower 1/2 of this synchro is the Oil Pump Drive, an important part, lol

Your 1994 will just have the Oil Pump Drive, so swap it over to the 1997, one less thing to go wrong :)

Leak down test is done with heads on, with air pressure, not sure any fluid "leak down" would tell you much
You can test the valves in the heads that way, with water
The 4.0l OHV bottom end, bearings and rings, held up pretty well, 400k miles is not unexpected

If you were going to change the bearings then you would just change the rings

If you have the oil pan off then changing the oil pump is not an expensive thing to do, and of course a new oil pan gasket, these like to leak, on any engine, lol
 

97rangershmazda

New Member
Joined
Sep 12, 2020
Messages
7
Reaction score
0
Points
1
Location
Norcal
Vehicle Year
1994
Make / Model
Mazda B4000
Transmission
Manual
So I'm pulling the 94 4.0 engine out. The guy I got the engine from gave me, Engine, Wiring harness, flywheel, so I bought new heads for the 97 block which it is. Shoulda clarified that sorry.
 

97rangershmazda

New Member
Joined
Sep 12, 2020
Messages
7
Reaction score
0
Points
1
Location
Norcal
Vehicle Year
1994
Make / Model
Mazda B4000
Transmission
Manual
I think I did make one mistake though, I bought a head gasket kit for a 94 and I think the block is different is it not? So I'm going to probably have to order another for. A 97..
 

97rangershmazda

New Member
Joined
Sep 12, 2020
Messages
7
Reaction score
0
Points
1
Location
Norcal
Vehicle Year
1994
Make / Model
Mazda B4000
Transmission
Manual
97rangermazda:

You need to know that if you are installing 97 4.0 ohv heads on a 94 4.0 ohv bottom end you will be increasing the compression approximately 1.0 whole point; resulting in a 10:1 (ish) compression ratio engine vs the stock 9:1. You should only use premium fuel in this set up.

Also, your 97 heads may be a 98TM casting which has the smaller, more round exhaust ports. Post a pic of the 97 head exhaust ports so that you know what you'll be dealing with.

Are you doing anything with the valve train or just reusing the 94 or the 97's push rods/rockers?

I highly recommend having your valve guides measured prior to reassembly. If yours are anywhere as worn as mine were, your rebuild will drink oil and suffer on overall performance.
The engine came out of a 1997 ford ranger that I'm rebuilding and putting into my 1994 Mazda B4000 in place of the 94 engine that's in it.
 

Attachments

RonD

Official TRS AI
TRS Technical Advisor
Joined
Jun 2, 2012
Messages
25,290
Reaction score
8,290
Points
113
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
I don't think it would matter for the head gaskets, but I would get 1997 gasket set/kit if possible
Also new head bolts, they can't be reused
 

gaz

Well-Known Member
U.S. Military - Veteran
Joined
Sep 21, 2007
Messages
1,382
Reaction score
623
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" (2" suspension), BII 4" suspension
Total Drop
Ranger 5sp, BII A4LD
Tire Size
Ranger 33"/4:10LS, BII 29"/3:73LS
My credo
Deengineer until it is how Blue Oval should have sold it!!
97rangerhmazda:

OK, now I understand; your installing the 97 4.0L into you 94 B4000 after it's rebuilt.

Three things I would incorporate:

1) new oil pump
2) new timing set
3) new water pump

I recommend considering:

a) rocker tip hardening/socket insert treatment, by Delta Cam of Tacoma Washington.
b) adjustable push rods by Smith Brother's, custom to YOUR engine.
c) taper hone your stock throttle body to 64mm; this will result in an increase of 3 hp across the RPM band.

I am currently rebuilding a 94, 4.0L with all of these and several other improvements. On paper it is expected to make over 29 mpg at normal legal highway speed and develope maximum 242hp/321tq at the crank. So depending on your performance goals, there is room for improvement.
 
Last edited:

sgtsandman

Aircraft Fuel Tank Diver
TRS Forum Moderator
U.S. Military - Active
TRS 20th Anniversary
TRS Event Participant
Ham Radio Operator
GMRS Radio License
Joined
Mar 11, 2017
Messages
12,695
Reaction score
12,381
Points
113
Location
Aliquippa, PA
Vehicle Year
2011/2019
Make / Model
Ranger XLT/FX4
Engine Size
4.0 SOHC/2.3 Ecoboost
2WD / 4WD
4WD
Total Lift
Pre-2008 lift/Stock
Tire Size
31X10.5R15/265/65R17
I changed the thread title to avoid future confusion.
 

Sponsored Ad


Sponsored Ad

Staff online

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Truck of The Month


Kirby N.
March Truck of The Month

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Follow TRS On Instagram

TRS Events

25th Anniversary Sponsors

Check Out The TRS Store


Sponsored Ad


Sponsored Ad

Sponsored Ad


Amazon Deals

Top