Scott B.'s 4.0 OHV Rebuild

After 313,000 miles, I have decided it is time to replace the engine and transmission in my '93 Ranger. My original engine and transmission have given flawless service over the past 17 years and 3 months. The engine always starts with a bump of the key, and the transmission does not slip.

Part of me thinks I should keep going - to see how many miles I can get on the original equipment. Of course, the engine is leaking oil - a slow leak, that I've had for many years, has gotten a lot worse since I came back from Colorado last year. The transmission leaks a little, too - and only boiled over once, about 10 years ago.

For me, there are three options for replacement - swap in a 5.0, swap in a 4.0 SOHC, and rebuild (and build) the original 4.0 OHV. After much contemplation, I have decided to rebuild/build the original 4.0, and replace the A4LD transmission with another A4LD.

I have done a lot of research about the engines online, and worked out my requirements for the replacement. With that, I have developed a game plan, if you will, of how to build this engine.

Along with this new engine and transmission, will be many other changes/upgrades to the truck. For those that may be interested, you can follow those updates in my registry.

 

[Scott B.]

Engine Specifications

* This list is almost complete/correct. As final decisions are made, I will update here. *


Block
’93 Block
Line honed
Bored 0.030 or 0.048 over
Decked

Main studs, ARP
Girdle ? (Tom Morana Racing)

Crank
Stock crank
Ground 0.010

Crankshaft sleeve
Microsleeve

Rods
Stock or New?

Pistons
keith black hypereutectic pistons (95 style),

3.982 or 4.00 bore
9 – 9.5:1 compression

Bearings
Clevite
Main – MS-860-P
Rod – CB-723-P
Cam – SH-1441-S

Rings
total seal rings,

Harmonic Balancer
Motorcraft - 8L2Z-6B321-A

Crank pulley bolt
Motorcraft - E7RY-6A340-B

Freeze plugs, Engine block heater

Rotating assembly balanced

Oil Pump
Melling

Water Pump
Ford Motorcraft

Heads
Engine Quest
95TM
Port, polish, bowl work
Match water ports, enlarge

Head Bolts
Fel-Pro

Valvetrain
Delta Cam Rocker Arm Assembly F-40
Hardened tips, pushrod cups

Pushrods
Smith Brothers
54A-A 5.525”
(5.525” pushrods minus machined height)
(5.550” for stock rockers)

Valves
SI SEV-2027 exhaust, SEV-2028 intake

Valve Retainers
8mm keepers (for LS1 engine)
Crane Cams 99947-12

Valve Springs
Competition Cams 988-12

Cam
Competition Cam 410

Lifters
Aftermarket set from eBay

Timing Set
Cloyes
Tensioner

Intake
Port match lower intake

Injection
19# matched injectors ??

Ignition Module
Accel

Plug Wires
Jacobs

Gaskets
Fel-Pro
Ford (lower intake)

Headers
JBA, Jet Hot Sterling Silver titanium ceramic coating

Catalytic Converter
Magnaflow (if original needs replacing)

Exhaust
JBA cat-back

MAF
95 Mustang 70mm

Throttle Body
BBK 66mm

 

[Scott B.]

Transmission Specifications

Transmission
A4LD – Ford remanufactured

Flex Plate
Motorcraft

Torque converter
??

 

[reapereviltwin]

 

[Brandon96]

Hey this looks familiar!!!

It looks like I might get into mine before yours, if I can help yah out with anything let me know!

 

[jd4242]

Why the 410 cam? The 422 will make way more power and how do you plan on getting 9.5:1 compression?also the 410 doesn't need the dual 988 springs.

 

[Scott B.]

Why the 410 cam?

I'm leaning towards the 410 for drivability reasons. I need ultimate reliability - would like the engine to last another 300K miles. My driving needs are focused on low speed off road as opposed to high speed. Also, I plan to build an expedition-type camping trailer, and will tow that off road.

The 422 has a higher RPM power band, which I think will be less than ideal for my needs.

Also, the 422 will not get as good gas mileage as the 410 (much longer duration).

The decision is not final yet - am I off in any of my assumptions?

how do you plan on getting 9.5:1 compression?

By boring the cylinder to 4.00", I will be able to use a standard small block Ford (or Chevy) piston. I hope to find one that has the proper wrist pin and height for this application. Worse comes to worse, I can either have pistons custom made or use stock '93 style OHV pistons, and dish the piston tops.

the 410 doesn't need the dual 988 springs

True - the springs will be determined after final cam selection.

 

[Turdle]

Why not bump the compression to the max allowable since 9.5 will require premium fuel anyway? Maybe around 10.1:1

 

[Scott B.]

Why not bump the compression to the max allowable since 9.5 will require premium fuel anyway? Maybe around 10.1:1

That was my original plan, but my engine builder is recommending 9.5:1 as a maximum. In his experience, street gas is not always enough for 10:1.

Another concern is what is going to happen to gas in the future? Lower maximum octane, ethanol, etc. I don't want to get in a situation where I have to add octane booster with every tank.

 

[Turdle]

That was my original plan, but my engine builder is recommending 9.5:1 as a maximum. In his experience, street gas is not always enough for 10:1.

Another concern is what is going to happen to gas in the future? Lower maximum octane, ethanol, etc. I don't want to get in a situation where I have to add octane booster with every tank.

You might want to find out if the valve overlap of your cam of choice will reduce the static compression.

 

[jd4242]

not trying to sell you on anything just want to clear things up.my first build i built my motor with the 410 and was so unhappy with it i pulled the motor back apart to put the 422 in,happy now

The 422 has a higher RPM power band, which I think will be less than ideal for my needs.

next time you out driving around note the average rpm you drive at or would be towing at off road.the 410 starts at 800rpm,basically idle and the 422 starts a 1600 about cruising speed.the difference is the 422 makes way more power at any of the rpm range

Also, the 422 will not get as good gas mileage as the 410 (much longer duration).

this may be true but has not been proven as the 422 makes more power so less gas is need to move the same amount of weigh.
much longer???
(410)--Duration 256/266, Lift .465/.500
(422)--Duration 270/284, Lift .500/.500

By boring the cylinder to 4.00", I will be able to use a standard small block Ford (or Chevy) piston. I hope to find one that has the proper wrist pin and height for this application. Worse comes to worse, I can either have pistons custom made or use stock '93 style OHV pistons, and dish the piston tops.

the cylinder walls are very thin on the ohv motor and can not handle having it bored that much.the first gen block are the thickest adn the max safe i would take them would be .03 or .04 and .04 is pushing it.most people would not take it over .03.also if you use stock 93 piston they are dished -17.5cc and with 95tm heads that will put you at 10:1 or 9.8:1 with it bored to .03

True - the springs will be determined after final cam selection.

to use those spring the spring seat need to be milled down also,means more costly work for no reason if you go 410.also stock retainers and keepers will work fine with those springs or those valves

 

[jd4242]

That was my original plan, but my engine builder is recommending 9.5:1 as a maximum. In his experience, street gas is not always enough for 10:1.

Another concern is what is going to happen to gas in the future? Lower maximum octane, ethanol, etc. I don't want to get in a situation where I have to add octane booster with every tank.

9:1 is stock and i believe the new ex comes at 9.8:1.many cars have over 10:1 stock.many people on here have done the 95tm head swap to go with 10:1 and have no problems. i have around 10.6:1 and have ran my truck on 87 gas and it ran fine,didnt like it but ran fine.my 388 stroker had 11.5:1 and i ran it on 93 gas.you can also run colder plugs or back the timing off instead of running octane booster

 

[Turdle]

If you keep the compression to less than 192psi you will not have fuel issues.

 

[jd4242]

If you keep the compression to less than 192psi you will not have fuel issues.

huh i havent tested mine sense its been back together.what was stock and where do you get that number from,seems like ive heard that magical 200 before:scratch:

 

[Turdle]

huh i havent tested mine sense its been back together.what was stock and where do you get that number from,seems like ive heard that magical 200 before:scratch:

Yeah-200 is safe for aluminum heads and 93 octane IIRC

I think stock is around 185. I might stand corrected though.

 

[Scott B.]

the cylinder walls are very thin on the ohv motor and can not handle having it bored that much.the first gen block are the thickest adn the max safe i would take them would be .03 or .04 and .04 is pushing it.most people would not take it over .03.also if you use stock 93 piston they are dished -17.5cc and with 95tm heads that will put you at 10:1 or 9.8:1 with it bored to .03

My understanding from Tom Morana and Doug Anderson was that the 90 - 93 blocks could take a 0.048" overbore - the newer blocks can only handle a 0.030" overbore.

I would hate to be wrong on this...

 

[Scott B.]

9:1 is stock and i believe the new ex comes at 9.8:1.many cars have over 10:1 stock.many people on here have done the 95tm head swap to go with 10:1 and have no problems. i have around 10.6:1 and have ran my truck on 87 gas and it ran fine,didnt like it but ran fine.my 388 stroker had 11.5:1 and i ran it on 93 gas.you can also run colder plugs or back the timing off instead of running octane booster

So, if I jump up to 10:1, you think I would be OK on pump gas (93 octane)?

I would much rather go for the higher compression - more power, cleaner burning - and I don't mind running the higher octane fuel.

 

[Scott B.]

422 Questions

Seeing as I would really rather use the 422, some questions:

1. How does the engine idle? I don't mind if it sounds "lumpy" (in fact, would prefer it!), but does it idle at 600 RPM?

2. Will I need to change injectors to feed the fuel?

3. Will the computer handle it? I do have a de-tuned Superchip, that I am considering replacing with a Jet (or ???)

I'm not trying to build a mileage monster, but I do drive a lot, and like to wheel out west - so 15 MPG would be appreciated.

 

[Falconkeeper]

Unless you are planning on going to some really cold areas, I don't see a need for a block heater. I spent 5 winters in Minot, ND, and needed a block heater to start in the winter (needed to heat the oil so the engine would turn fast enough to start). Anywhere south of Nebraska and east of the Rockies, you won't need a block heater IMO.

 

[Scott B.]

Unless you are planning on going to some really cold areas, I don't see a need for a block heater. I spent 5 winters in Minot, ND, and needed a block heater to start in the winter (needed to heat the oil so the engine would turn fast enough to start). Anywhere south of Nebraska and east of the Rockies, you won't need a block heater IMO.

While I agree with you, when I ordered my truck from Ford, I selected that as an option (at the time, I lived in SoCal, so they thought I was nuts!)

I use mine in Georgia occasionally - it makes for easier, less engine wear starting, and, I have almost instant heat.

I've been wheeling in the mountains in the wintertime (snow on the ground), and, when staying in a motel, have plugged the truck in in the morning. OK, because I could...