Need info on 251 engine

[Michel D]

Do you think it is a good thing to put some Zinc-plus oil additive in your engine!
The new oil dose not have ZDDP anymore.
I just buy some lucas tb Zinc-plus oil additive to put in my engine i hope this will help!

[Phil Waterman]

Hi Michel

There is a lot of information on web about the need for or no need for zinc additives.

I've asked at the machine shop that has done my engine rebuilds, shop foreman there has something like 30 years experience. His comment was born out by much of the reading I've done, most of the problems he has seen seem to come with high RPM engines with high valve spring loading. In the next breath he said but it couldn't hurt to use a major name brand oil supplement. Which is what I have done.

There are various engines that have had camshaft wear problems, generally poor heat treating, I don't know if Dodge's fall in that group

I guess I would ask my self with the amount we drive MVs we end up changing the oil once at most twice a year, so $10 extra for good oil additive is probably good insurance.

Cheers Phil

[Bob Carriere]

Hi Michel

Much has been written on which oil to use in old engines and it is becoming confusing.

The concern is particularly critical when you have just spent $3000 rebuilding an old engine to factory specifications and you want to protect your investment.

My advice..... why take a chance...?

A freshly rebuilt engine will have a lot of parts that have to "wear in"...such as rings/cylinders..... camshaft lobes/solid lifters.... just to mention the big ones. It seems that most modern "car" oil has been modified to lessen contamination of the environment, lower cost, match closer tolerances of new engines, meet high temperature and high revs.......

Experienced writers have advised that the best oil left on the market for old style rebuilt engines are the oil rated for diesel engines with the possibility of adding the zinc additives. Diesel engine oil is rated for higher friction, temp. and for at least another 2 or 3 years will still have some zinc additives... they are also being phased out apparently. Most new diesel truck...Ford or GM ... will void the factory warranty if you do not use diesel engine oil and opt for the cheaper "car" engine oil......

Stick to known brands.... not the Walmart specials..... use the additives and change the oil Spring and Fall..... even if the engine has not run much over the Winter months..... some of the additives such as anti oxydants will be depleted/exhausted..... and then fresh oil at the end of the Summer season before storing for the Winter.

I initially started my Chev 261 on synthetic but since switched to Rotella diesel engine oil 10w-40...... oil pressure is about 5 pounds higher on the Shell oil compared to the synthetic.....my engine will not run in the Winter and I believe that the Rotella may be better in the long run.

Don't skimp on the oil filter..... cheaper to replace everytime than pay for repairs.

Unless you really abuse you DODGE and pull stumps with it the engine should last you a long time...... just DO NOT OVER REV the engine..... it has long connecting rods that love to fly.... usually through the side of the block.

An M37 or radio truck fully loaded with camping gear, fuel, outboard motor is heavy enough to push the vehcile downhill faster than the engine can hold back and the weight of the truck/cargo will over drive the 251 to destruction... oddly enough driving the truck in low range and revving against the governor does not seem to do as much damage..... at least in my experience it's always been does long down hill runs that have busted up blocks..... besides at 65 mph you can brake only once in a Dodge.... you have brake fade for at least 20 minutes after that....

Fresh HD oil, filters, additives..... and it will drive you to your grave....!

Boob