OHV rebuild - Ranger-Forums - The Ultimate Ford Ranger Resource


4.0L OHV & SOHC V6 Tech General discussion of 4.0L OHV and SOHC V6 Ford Ranger engines.

Reply
 
LinkBack Thread Tools Search this Thread
  #1  
Old 10-10-2013
fraser19's Avatar
Member
Thread Starter
 
Join Date: Jul 2009
Location: calgary alberta
Posts: 275
OHV rebuild

Hello,

As it stands my current 1996 ranger is starting to get a little burnt out. I have owned this truck for the last 30,000km. I don't think the previous owners did much for it. I believe the head is cracked over cylinder #3 as I have a misfire that wont go away. Also the truck was overheated and now consume a reasonably large amount of oil. This engine has still some life left in it but it is on its way out.

I am sure a good portion of people can relate to this but I really like my ranger. Sure there are a lot of times I wished I had a full size but there is something about rangers that keeps my coming back to them. This is my third one.

So what I was thinking was I would get a junk yard engine. Tear it down and send it out to get hot tanked cleaned and a .020 bore on the block. Having had both OHV engines and SOHC engines I do prefer the OHv sure it doesn't rev as fast but it seems to put down the torque very nicely.

Now here is where the fun comes in. The OHV has a 9:1 compression ratio and the SOHC has a 9.7:1 compression ratio. It is my understanding that the pistons are interchangeable between the two engines. Now what I am not sure of is will putting the SOHC flat top pistons give me a 9.7:1 compression ratio?

Since I will be replacing the heads I figured I would take them to the guys who will be cleaning up the block. They have pretty good prices on porting and valve jobs. Get them to build up a very nice flowing set of heads.

Also as far as camshafts go I have not really decided to go with the 422 or 410. Most likely the 410 due to it making power a little lower than the 422 in the RPM's.

All other parts will come from a generic rebuild kit. I would like to replace as much as I can. Now I know this seems like it will be expensive however I was quoted $3200.00 for a re-manufactured 4.0 OHV. So I feel much better about going this way.

Now I know there is always the option to put in a v8. I really don't want to go that way I am not building an anything more than a new engine to put in my ranger that in bolt in and never deal with again other than basic maintenance. I don't want to spend a bunch of time fabricating things for something I have never done before. I want to build an engine while my current one is in the truck and be able to switch the old one out for the rebuilt one in a weekend.

I feel that I have a good plan laid out for a nice OHV. The only thing I am not sure about is the pistons. While I would really like the increase of power from extra compression I haven't seen a lot of info about people going that way. Any thoughts for that part of the equation?
Reply With Quote
  #2  
Old 10-10-2013
StxDangerRanger's Avatar
RF Veteran
iTrader: (2)
 
Join Date: Dec 2010
Location: Flat Rock, Mi
Posts: 6,313
I might be wrong, but i thought compression had to do with the whole package. Camshaft, Heads and Pistons.

If it were me, I'd just put in what came out (meaning, stick with the OHV parts). The gains you'll see from going to a higher compression isn't really worth it.
Reply With Quote
  #3  
Old 10-10-2013
fraser19's Avatar
Member
Thread Starter
 
Join Date: Jul 2009
Location: calgary alberta
Posts: 275
Quote:
Originally Posted by StxDangerRanger View Post
I might be wrong, but i thought compression had to do with the whole package. Camshaft, Heads and Pistons.

If it were me, I'd just put in what came out (meaning, stick with the OHV parts). The gains you'll see from going to a higher compression isn't really worth it.
Yeah I was thinking about that over the night. I would rather build a reliable engine than a Frankenstein. Sure it may make more power while it is running but a higher CR is useless when the engine is out of the truck being worked on.

The added compression from piston ring that seal should be good enough.
Reply With Quote
  #4  
Old 10-11-2013
Scrambler82's Avatar
Old Guy UserÖ ltr
iTrader: (12)
 
Join Date: Jul 2009
Location: SoCal
Posts: 6,765
Quote:
Originally Posted by StxDangerRanger View Post
I might be wrong, but i thought compression had to do with the whole package. Camshaft, Heads and Pistons.
Compression ratio is a piston and heads thing only, the cam is to operate the valves and has nothing to do with compression except closing the valve so you can actually get some.

Going to a higher compression ratio will result in a little more power but also you will need to run higher octane fuel.

I know you said no V8 but a good running STOCK V-8 will give you more torque than a prepped-street v6 and run longer and better.

Yes a V8 sometimes takes a little longer to install but not always, donít write it off until you get some numbers together on the V8 swap.

Canít help you on the SOHC Piston fitment but talk about taking extra time, you need to measure them up first to see if they are even close, OD, Height, valve reliefs, ring groove locations, any dome versus flat top and then you need to mount on a rod, put on the rings and start measuring again. You will need deck heights, top of piston placement referencing the block and the heads, block bore vs OD of pistons, and then you need to put the heads on the cam in and see where the valves go, too high, too low.

What you are thinking on is a complete restructuring of the upper end of the engine and you will need to check everything, TWICE and then you get to fire it up, not knowing for sure if the measurements were completely correct and if you are lucky it will run. Then the higher compression ratio throws a code because of excessive detonation.

I have no idea of your ability, your profession maybe a mechanic but this isnít just bolt some stuff together and throw it in and drive away, you will need to play the game and do the math and hope.

OK back to the V8Ö with a kit it is a bolt in, if the V8 was rebuilt stock it will still have a lot more HP and Torque to move a Ranger than a V6 and it will run for a long time and give all the power you should normally need. If you want more HP there are all kinds of kit out there for the 5.0L Windsor's and you can actually bolt on the HP as needed.

OK too much talk, just think before leaping; there is a lot of work to rebuilding an engine with stock parts little lone switching thing out !
Reply With Quote
  #5  
Old 10-11-2013
fraser19's Avatar
Member
Thread Starter
 
Join Date: Jul 2009
Location: calgary alberta
Posts: 275
Quote:
Originally Posted by Scrambler82 View Post
Compression ratio is a piston and heads thing only, the cam is to operate the valves and has nothing to do with compression except closing the valve so you can actually get some.

Going to a higher compression ratio will result in a little more power but also you will need to run higher octane fuel.

I know you said no V8 but a good running STOCK V-8 will give you more torque than a prepped-street v6 and run longer and better.

Yes a V8 sometimes takes a little longer to install but not always, donít write it off until you get some numbers together on the V8 swap.

Canít help you on the SOHC Piston fitment but talk about taking extra time, you need to measure them up first to see if they are even close, OD, Height, valve reliefs, ring groove locations, any dome versus flat top and then you need to mount on a rod, put on the rings and start measuring again. You will need deck heights, top of piston placement referencing the block and the heads, block bore vs OD of pistons, and then you need to put the heads on the cam in and see where the valves go, too high, too low.

What you are thinking on is a complete restructuring of the upper end of the engine and you will need to check everything, TWICE and then you get to fire it up, not knowing for sure if the measurements were completely correct and if you are lucky it will run. Then the higher compression ratio throws a code because of excessive detonation.

I have no idea of your ability, your profession maybe a mechanic but this isnít just bolt some stuff together and throw it in and drive away, you will need to play the game and do the math and hope.

OK back to the V8Ö with a kit it is a bolt in, if the V8 was rebuilt stock it will still have a lot more HP and Torque to move a Ranger than a V6 and it will run for a long time and give all the power you should normally need. If you want more HP there are all kinds of kit out there for the 5.0L Windsor's and you can actually bolt on the HP as needed.

OK too much talk, just think before leaping; there is a lot of work to rebuilding an engine with stock parts little lone switching thing out !
Yes I would love a V8 however I want to keep it a manual trans. I have found very little info on how to do a V8 with a MT and I really don't want to be sitting there with a truck in 1000 pieces.

I am reasonably mechanically inclined. I rebuilt a few 350 chevy engines. I did three years of mechanics in high school. My profession is in addictions counseling. unrelated but gives more info about myself. I own a 2004 BMW that I have been doing all the work myself on and the rangers are pretty straight forward compared to the M54 in the BMW.

I have next to no fabrication skills. I cant weld or make much for parts but I can put existing parts together pretty damn well.

I would live to do a V8 swap but I just wont unless I have someone to help me who has done it before. If i could find someone like that I would build a very nice 5.0 over the winter and get them to help me install it in the spring.
Reply With Quote
  #6  
Old 10-12-2013
Scrambler82's Avatar
Old Guy UserÖ ltr
iTrader: (12)
 
Join Date: Jul 2009
Location: SoCal
Posts: 6,765
I know what you mean on the MT.

With the hydraulic clutches, it has to be possible.

Anyway, building with non stock part, i.e. piston swap, can be interesting.
Check and recheck.

Good luck with the project.
Reply With Quote
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Lifter noise on new engine rebuild 4.0l OHV jademan 4.0L OHV & SOHC V6 Tech 14 03-15-2012 06:48 PM
4.0 OHV rebuild. Rangerkid 4.0L OHV & SOHC V6 Tech 29 05-26-2009 01:05 PM
99 4.0 Ohv Rebuild 4.0ltwins Project Logs 12 12-23-2008 12:48 PM
T5 Issues + Rebuild My91Ranger Drivetrain Tech 16 09-21-2008 06:25 PM
Engine Rebuild, Or Swap? spec_ops57 General Ford Ranger Discussion 8 03-06-2006 03:51 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -6. The time now is 07:30 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.