Engine building help...

[PNWEx]

Trying to build my first engine. I would like to build an engine to replace the one in my 94 limited Explorer. It has begun to burn coolant and leak from the rear main seal.

I have a few questions to clarify a few things and would appreciate any help or ideas. I am building this for a little more power and a little more responsive when I hit the gas but most importantly, longevity.

My plan so far is to buy a junker engine from the local pick n pull. No Explorers but a couple 94 Rangers.
Have said engine Magna Fluxed and cleaned.

Then add:
Melling High Volume oil pump
410 Cam from compcam
BBK throttle body
Bigger MAF
95TM HEADS


Am I missing anything? Again not building this to win in a race but to be able to pass 18 wheelers would be nice and longevity. I would like to be able to pass this onto my son in a couple of years without worrying every time he gets in.


Again any input is appreciated. Thanks again.

 

[Josh P]

A stock 302 would give you the slight additional power you desire, and you'd have a choice of a better transmission.

 

[PNWEx]

A stock 302 would give you the slight additional power you desire, and you'd have a choice of a better transmission.

Agreed. However, that would require a new wiring harness and a lot of work I am not skilled, nor equipped enough to do. I have read a lot of the forums on here about the subject. Rewiring a truck and buying a new transmission which would have to be some sort of c4 variation. I just want a solid OHV 4.0, basically fixing the problems the engineers didn't foresee.

 

[Josh P]

Agreed. However, that would require a new wiring harness and a lot of work I am not skilled, nor equipped enough to do. I have read a lot of the forums on here about the subject. Rewiring a truck and buying a new transmission which would have to be some sort of c4 variation. I just want a solid OHV 4.0, basically fixing the problems the engineers didn't foresee.

Some people have issues with pinging using 95TM heads with the 94 and older pistons.

I'm not trying to talk you out of your build plan, there are places, and people that make engine swap harnesses. I've been down this road, rebuilding what I got, then the transmission goes out. By the time it's all done I spent more than if I put something better in it's place.

 

[410Fortune]

We do see this a lot, an engine is rebuilt only to have the trans go out a short time after

Often this is due to the engine install itself perhaps some debris or water found its way inside the trans cooler lines, perhaps the new engine and the strain of having engines yanked and the installed causes it? Whatever it is high mile automatics tend to fail quickly when mated to a newer engine… sometimes (not always)
But it happens engiugh that us guys notice. I’m the guy who brings home all the broken explorers and rangers


The 410
Cam won’t do much for you not without going all out and building a performance 4.0
Doesn’t the 410 cal grind also require some supporting mods like pushrods and rockers? Skip all that and keep it stock imo. The pushrod is a money pit when it comes to performance for very little gains

Why not try and find a later engine to start with? Like instead of rebuilding your 94 I would try to find a lower mile pushrod 4.0!from a 98-2000 and use the block and heads from that…. Re fresh a known good engine is far cheaper then rebuilding a 4.0 ohv. Just the machine work will cost you as much as a better engine

The 96-00 version of the 4.0 is far superior to the 94 version imo so I would start with one of those. If you get a good enough one then all you have to do it replace all the gaskets and tune up parts, dress it to be a 94 (accessories and intake) and drop it in

 

[PNWEx]

We do see this a lot, an engine is rebuilt only to have the trans go out a short time after

Often this is due to the engine install itself perhaps some debris or water found its way inside the trans cooler lines, perhaps the new engine and the strain of having engines yanked and the installed causes it? Whatever it is high mile automatics tend to fail quickly when mated to a newer engine… sometimes (not always)
But it happens engiugh that us guys notice. I’m the guy who brings home all the broken explorers and rangers


The 410
Cam won’t do much for you not without going all out and building a performance 4.0
Doesn’t the 410 cal grind also require some supporting mods like pushrods and rockers? Skip all that and keep it stock imo. The pushrod is a money pit when it comes to performance for very little gains

Why not try and find a later engine to start with? Like instead of rebuilding your 94 I would try to find a lower mile pushrod 4.0!from a 98-2000 and use the block and heads from that…. Re fresh a known good engine is far cheaper then rebuilding a 4.0 ohv. Just the machine work will cost you as much as a better engine

The 96-00 version of the 4.0 is far superior to the 94 version imo so I would start with one of those. If you get a good enough one then all you have to do it replace all the gaskets and tune up parts, dress it to be a 94 (accessories and intake) and drop it in

Yes to all of these things, I know the trans would be next on the list which I have been going back and forth with the idea of throwing a 5 speed manual. My 4.0 only has 130k original miles so the trans hasn't been beat on too bad. Ya know, rich people stuff, they bought it, got tired of it and parked it. But I am not unaware that with rebuilds come trans problems.

I think I might just tear it down and replace the heads, see how long that holds up. But it's eating gas and coolant and as my daily I can't have that.

 

[PNWEx]

To put a 96 in it what would that entail? Just replacing the sensors with the ones on my 94? My limited also has the over head display which I don't to loose.

 

[PNWEx]

We do see this a lot, an engine is rebuilt only to have the trans go out a short time after

Often this is due to the engine install itself perhaps some debris or water found its way inside the trans cooler lines, perhaps the new engine and the strain of having engines yanked and the installed causes it? Whatever it is high mile automatics tend to fail quickly when mated to a newer engine… sometimes (not always)
But it happens engiugh that us guys notice. I’m the guy who brings home all the broken explorers and rangers


The 410
Cam won’t do much for you not without going all out and building a performance 4.0
Doesn’t the 410 cal grind also require some supporting mods like pushrods and rockers? Skip all that and keep it stock imo. The pushrod is a money pit when it comes to performance for very little gains

Why not try and find a later engine to start with? Like instead of rebuilding your 94 I would try to find a lower mile pushrod 4.0!from a 98-2000 and use the block and heads from that…. Re fresh a known good engine is far cheaper then rebuilding a 4.0 ohv. Just the machine work will cost you as much as a better engine

The 96-00 version of the 4.0 is far superior to the 94 version imo so I would start with one of those. If you get a good enough one then all you have to do it replace all the gaskets and tune up parts, dress it to be a 94 (accessories and intake) and drop it in

Isn't the 96 and up the sohc? Which is infamous for timing issues?

 

[Josh P]

Isn't the 96 and up the sohc? Which is infamous for timing issues?

The ohv was available till 2000. To use a newer Block, you reuse the accessories, intake off the original engine on the replacement. Sensors, etc get transferred over. The M5OD is a massive upgrade over the A4LD. Your fuel mileage will go up 1-2 mpg with the manual.

 

[PNWEx]

The ohv was available till 2000. To use a newer Block, you reuse the accessories, intake off the original engine on the replacement. Sensors, etc get transferred over. The M5OD is a massive upgrade over the A4LD. Your fuel mileage will go up 1-2 mpg with the manual.

Any one on here done a write up on something like this?

 

[Nedwreck]

Is the coolant issue from a bad intake gasket letting a little coolant into a intake runner? I sorta went through some of these decisions many years ago, ultimately we cleaned up the existing engine, fixed some gaskets and seals etc, and put it back in. The valvetrain on mine was great, and that seems to be the problem with these. IIRC it had 185k or so when we did that, it's well over 450k now lol. But, I drive easy, and I'm a real stickler for maintenance. My A4LD got a second trans cooler and regular maintenance (and a rebuild at 150K)

Have you done a compression test?

 

[410Fortune]

With 130 k new heads might just save that ol ohv

5 speed conversion, now we are talking!

 

[Josh P]

Any one on here done a write up on something like this?

This covers most of it, and the last message I didn't see till now has the pedal assembly you need, if you care to make an offer on them.

How to: - COMPLETED: Auto to Manual swap - 1991 Explorer

Hey all. First post! Thanks to everyone for all the information about auto to manual transmission swaps. I finished mine this weekend and have a few notes I want to share. Please read this original and extremely helpful post that guided me through the process. There are a couple more things I...

www.explorerforum.com

 

[PNWEx]

Is the coolant issue from a bad intake gasket letting a little coolant into a intake runner? I sorta went through some of these decisions many years ago, ultimately we cleaned up the existing engine, fixed some gaskets and seals etc, and put it back in. The valvetrain on mine was great, and that seems to be the problem with these. IIRC it had 185k or so when we did that, it's well over 450k now lol. But, I drive easy, and I'm a real stickler for maintenance. My A4LD got a second trans cooler and regular maintenance (and a rebuild at 150K)

Have you done a compression test?

I have not, I will be getting a tester this weekend. I have been thinking about adding a larger trans cooler but for right now she's running strong. As for the coolant, I can see where it's coming out I believe. If I look in my driver's side front wheel wheel right above the header I can see what looks like where coolant is spraying out or leaking. I'll try to get a picture when it's not raining.

 

[PNWEx]

So, I know I can't run the 98tm heads with stock pistons without doing some other things correct? So, can anyone recommend some good aftermarket heads?

I have read in previous posts that clearwater heads on ebay but then I read elsewhere that they are just rebranded Chinese recasts.

I would just like to get bang for my buck because it seems like I am just going to replace the gaskets down to the heads, throw some new heads on and hope for the best. I did have Ford put a new Camshaft sensor so, I am in too deep to stop now.

 

[Josh P]

So, I know I can't run the 98tm heads with stock pistons without doing some other things correct? So, can anyone recommend some good aftermarket heads?

I have read in previous posts that clearwater heads on ebay but then I read elsewhere that they are just rebranded Chinese recasts.

I would just like to get bang for my buck because it seems like I am just going to replace the gaskets down to the heads, throw some new heads on and hope for the best. I did have Ford put a new Camshaft sensor so, I am in too deep to stop now.

The 98TM heads have a fast burn chamber, the 94 ecm isn't calibrated for it. Some people have had no issues with those heads with the 90-94 pistons. Other people have reported pinging and needing premium gas. Engine Quest makes good heads, you will find them on Ebay

 

[PNWEx]

The 98TM heads have a fast burn chamber, the 94 ecm isn't calibrated for it. Some people have had no issues with those heads with the 90-94 pistons. Other people have reported pinging and needing premium gas. Engine Quest makes good heads, you will find them on Ebay

So to avoid any issues which heads would you recommend? Also I have read some conflicting reports about which gaskets to use. Any suggestions?

 

[Josh P]

If it was my build, I'd use the 98TM heads and get a custom ground camshaft. I'd get headers too. I've had good luck with the MLS type, they handle abuse really well.

 

[PNWEx]

If it was my build, I'd use the 98TM heads and get a custom ground camshaft. I'd get headers too. I've had good luck with the MLS type, they handle abuse really well.

wouldn't that require new pistons as well? If I were going to do a cam I would just do the 410. And build it all the way out. And it seems like it would be a waste of resources at this point.

 

[PNWEx]

How can you identify an Explorer with the newer OHV vs the SOHC without being at the vehicle? Like with the vin?