Which 4.0 engine is preferred, the OHV or the SOHC?

[gw33gp]

I don't see what is not to like about the SOHC engine. My 02 has served me well and is still running strong with over 292K miles on it. I did replace the timing chain tensioners twice but that is not a big deal. One of those times was at around 250K miles when I did a cam timing chain rebuild because I planned to keep it a lot longer. The problematic timing chain guides were still good.

I tow with and run my Ranger hard. I want as much power as I can get without over stressing it. It has been stated that the SOHC has a little more power than the OHV engine and you have to rev the SOHC to get power out of it. It is true you get a lot more power at higher rpm than the OHV is capable of, but the SOHC also has more power at lower rpm. I have a graph comparing the two in HP and torque. It shows the SOHC engine has more power and torque even at 2000 rpm and significantly more at higher rpm. I will post it when I find it.

I don't have a problem with anyone that likes the OHV engine, but don't base it on untruths.

 

[gaz]

@Angry Possum ,
These mid sized trucks were developed to be daily drivers that can do work. The power plant needs to make decent torque while yielding better fuel economy than a like V8 of era.

These new mid sized trucks/SUV's are much heavier and require more to get the same job done yet can hardly manage to get 25 mph to save their lives.

I've found 3 engineering faults with the OHV 4.0l:
1) the non-adjustable valve train
2) the exhaust ports on all but the 98 spec heads are too large
3) 91-97 exhaust manifold tubing (I.D.) is over sized for the head's exhaust port

I can live with maintaining a perfect cooling system, I simply can not respect an engine that will grenade if I don't change the timing chains every 80-100k/preventative maintenance. PLEASE NOTE: this statement represents my biased, negative opinion of the SOHC engine design...not the truth or a fact.

I'll will take a corrected OHV 4.0l any day but you couldn't pay me to use the SOHC Cologne version; I do however, very much like the SOHC pistons.

 

[rubydist]

There is no need to change timing chains every 100k miles on the sohc - however there is a need to replace the hydraulic tensioners about that often. It is a $50 repair, unless you cannot do simple wrenching yourself.

There is a need to post accurate information on the forum.

 

[Shran]

I’ve seen several OHV engines with well over 300k on them and one with 360… that one is still on the road, several years after I got an odometer reading from the owner. If you keep them cool they are ridiculously reliable.

Also seen several SOHC engines with over 300k - lots of others that died an early death though. IMO they are an enthusiast engine best suited to people who can keep up on maintenance. Unfortunately a lot of them ended up in Explorers and driven by soccer moms who do no maintenance.

 

[rusty ol ranger]

I’ve seen several OHV engines with well over 300k on them and one with 360… that one is still on the road, several years after I got an odometer reading from the owner. If you keep them cool they are ridiculously reliable.

Also seen several SOHC engines with over 300k - lots of others that died an early death though. IMO they are an enthusiast engine best suited to people who can keep up on maintenance. Unfortunately a lot of them ended up in Explorers and driven by soccer moms who do no maintenance.

There used to be a 2.9 around this place years ago in an 87 BII that claimed 662,000 (or 667,000, its been 15+ years) miles.

Just sayin.

 

[gw33gp]

I promised to show the graph comparing the power of the two engines. Here it is for anyone interested. As you can see, the OHV has a little more torque than the SOHC under 1600 rpm, but above that the SOHC shines. Up until 2200 rpm they both put out the same HP. After that the SOHC pulls away.

The problem with the cam drive chain system was pretty much resolved around 2003 with only a few exceptions. So, both engines are durable.

 

[rusty ol ranger]

I promised to show the graph comparing the power of the two engines. Here it is for anyone interested. As you can see, the OHV has a little more torque than the SOHC under 1600 rpm, but above that the SOHC shines. Up until 2200 rpm they both put out the same HP. After that the SOHC pulls away.

The problem with the cam drive chain system was pretty much resolved around 2003 with only a few exceptions. So, both engines are durable.

View attachment 102374

2.9, OHV 4.0, SOHC 4.0, hell even a 2.8...

Atleast its not a 3.0!

 

[lil_Blue_Ford]

2.9, OHV 4.0, SOHC 4.0, hell even a 2.8...

Atleast its not a 3.0!

Hey now, don’t be hating on the 3.0, they really only suck if you have an automatic

 

[19Walt93]

Hey now, don’t be hating on the 3.0, they really only suck if you have an automatic

Or if you want to go up a hill.

 

[racsan]

just imagine if your 3.0 had a 3.45 rear and you had to use 2nd to start out in because the transmission had no 1st gear.
Made my 2.3/4.10 seem like a hot rod though.

 

[lil_Blue_Ford]

Or if you want to go up a hill.

3.0, manual 2wd with 3.73’s and 235/70-15 tires and 3rd was good up to 70 mph, so hills were not a problem

 

[rubydist]

Or if you want to go up a hill.

Or if you live at 5000' elevation...

 

[rusty ol ranger]

Or if you live at 5000' elevation...

or tow

 

[2ndSS]

you do realise that if a rear cam chain breaks/jumps teeth on a sohc 4.0L you will have to pull the motor to replace, only way

 

[bobbywalter]

if its running.....drive it.