The difference between 4.0L OHV and SOHC

[97LTD]

Hi Folks,

I'm wondering if anyone knows of the difference between OHV and SOHC in 4.0 L engine. Which are better and why?... I have 1993 LTD with OHV and 97 with SOHC engine. I assumed they both are little different since SOHC are equipped with chains.

Any opinions or feedbacks are welcome!

 

[Billy177]

sohc has overhead cams the ohv is a poshrod engine the sohc has more power however the ohv may prove to be more reliable

 

[Magicfan25]

the SOHC is just that, single over head cam..the other 4.0 is a pushrod engine. SOHC has higher compression but also makes in the area of 50extra hp and more torque too. The 97 SOHCs had alot of problems with the timing chain tensioners...not sure if Ford will ever get this fixed on any of the pre 00 engines.

 

[wired_af]

the sohc has top end power. the ohv has bottom end power

while the sohc makes more HP, the sohc and ohv make a real close amount of torque

read the blue quote in my sig......

 

[Nate1]

Not exactly.
A SOHC vs a OHV will win. SOHCs produce more power at a cost. They are a pain to maintain, and you may have to revv higher to make that power. Engine maintnence for pre-00 owners can be a real headache, and we often wonder why we getter lower milage than the V8 guys, but if you have to spool up your engine to make that extra umph... you will guzzle more gas.

I like my sohc.... I had a pushrod and it feldt like a dog.... but then again it had no mods.

 

[wired_af]

i wasnt saying any of the engines would win in a race.

sohc makes 250lbs and ohv makes 220lbs.......

ive heard people racing the ohv and sohc

they say the ohv and sohc are neck and neck until 3000rmp where the sohc uses its top end

 

[dogfriend]

In general, a SOHC engine will be more efficient at higher engine speeds than a pushrod engine of the same size. A SOHC has less mass in the valve train than a pushrod engine of the same size, therefore the valves can move faster and the engine can rev higher.

Differences between SOHC, DOHC and Pushrod Valve Train

For the Explorer engines, the 4.0 OHV (pushrod) is an old engine design and has all of the kinks worked out over time. This engine was originally based on a German 2.8 L design which was used in the V6 Ranger (1983), then increased to 2.9 L for the Ranger and Bronco II(1986?), then increased to the 4.0 L for the Ranger and Explorer (1990-91).

The 4.0 SOHC was introduced in 1997 and has had some issues with the oil pump, the timing chain tensioners and the intake manifold o-rings. However, it is much better suited to motivating a 4200+ vehicle than the OHV engine. I would expect that most of the design issues have been worked out in the latest versions.

 

[bluestream]

I have both a SOHC and an OHV Explorer. I much prefer the OHV due to the fact that the engine produces it's torque at very low RPM. This is ideal for an off road vehicle, and well suited to a manual transmission. The SOHC drives much like a Japanese vehicle with the power produced at a higher RMP. This contributes to the poor fuel economy of the SOHC engine.

MY 2000 XLT has valve train rattle noise at 2400 to 2600 RPM. The noise defect is due to the fact that the valve timing design on these engines is basicly a POS. Ford has washed their hands of all these vehicles that are out of warranty, and their owners are SOL. I feel that if there is a defect, they should repair all the vehicles they have produced not just the ones with warranty left. I have lost a lot of respect for Ford due to the way they have treated me with this vehicle. I doubt that I could ever buy a Ford again. .

 

[yob_yeknom]

Sorry to disappoint you guys, but the SOHC engine makes its torque at the same speed as the OHV.

OHV - 220 @ 3000rpm

SOHC - 240 @ 3000rpm

 

[97LTD]

Thanks for the information.. I do understand clearly the differences. On what the information I read is most preferred SOHC engines. I still have the '93 Ltd with OHV engine that has 202,000 miles on it and it still all orginal engine and still running. I do have some questions about the SOHC engines in my '97 LTD and what to look for in a check up and making sure it is working properly. The OHV engines are less maintenance than SOHC that have to be checked periodically for chain and tensioners as what I heard that Fords having problem with the pre '00 SOHC engines. Does the owner have to check the SOHC engine or have the shop to do the job?

Does anyone have any experience with any problems with SOHC engines? I wonder is OHV (pushrod) stronger than SOHC?

I wonder why Ford has not made recall regarding the SOHC problems and that they fixed it on the post '00 engines? Did the Ford instead extended the warranty or what?

Sorry too many ??'s Just some infomation that I'm doing research on engines and Explorers. G'day

 

[MONMIX]

Dogfriend, you are a wealth of information.
We gotta do lunch one day.
Meet half way, say, Omaha ?

 

[fordkrazy]

the reason you have 200k+ mi on your 93 is why i like the OHV ...i think ford still has some kinks in the sohc they need to look at...its true test will be with the 3rd gen's since i assume they are heavier..

hey nweibley....could you check out my post
http://www.explorerforum.com/forums/showthread.php?s=&threadid=87437

i need a floridian's input

 

[dogfriend]

Originally posted by MONMIX
Dogfriend, you are a wealth of information.
We gotta do lunch one day.
Meet half way, say, Omaha ?

My OHV engine could make it to Omaha, but I'm not too sure the 5R55E transmission will make it that far.

My GF and I are planning a trip to Cancun just before Xmas....If you want to meet there, I'll buy the first round

 

[fordkrazy]

uhmmmm....(clear throat)....i believe you have the 4r55e as the 5r55e is for the sohc

 

[dogfriend]

Originally posted by fordkrazy
uhmmmm....(clear throat)....i believe you have the 4r55e as the 5r55e is for the sohc

Nope, all 97's with either 4.0 Engine (OHV or SOHC) have the 5R55E.

 

[bluestream]

Originally posted by yob_yeknom
Sorry to disappoint you guys, but the SOHC engine makes its torque at the same speed as the OHV.

OHV - 220 @ 3000rpm

SOHC - 240 @ 3000rpm

Not so...specifications for 2000 model year are OHV 225 Lbs./ft @2750 rpm....OHC 240 Lbs./ft@3250RPM

1991 model year had 225Lbs./ft @ 2400 rpm if my memory is correct.

 

[fordkrazy]

Originally posted by dogfriend
Nope, all 97's with either 4.0 Engine (OHV or SOHC) have the 5R55E.

sorry...my mistake..i just looked at my haynes manual and you are right.

 

[yob_yeknom]

Originally posted by bluestream
Not so...specifications for 2000 model year are OHV 225 Lbs./ft @2750 rpm....OHC 240 Lbs./ft@3250RPM

1991 model year had 225Lbs./ft @ 2400 rpm if my memory is correct.

My information shows the OHV had 220 @ 3000rpm for every year it was available.

I looked further and it shows 240 @ 3000rpm on the '97-99 SOHCs and 254 @ 3700rpm for the '00+

I wonder why we are finding different numbers?

Nevertheless, it's still all made at relatively low rpms.

 

[superman5787]

The 91 makes 220lb-ft at 2400rpm and only 155hp at 4200rpm. The 93 made 225lb-ft and 160hp at the same rpm as the 91's.

 

[97LTD]

Okay Guys... I have one question... Which is more expensive in repair or replace... OHV, SOHC engines.
I recently made a curious inquiry at different shops for OHV engines for factory rebuilt engine would run $3,000 to $4,000. I havent inquire about SOHC how much cost on that engine.

It appears that OHV is more reliable and last longer than SOHC since my 1993 with OHV has 203,000 miles and not one engine trouble. The idle is still smooth, no rough idle. I've taken good care of it and it lasts.