MTFCA Forum

I’m having my crankcase pan sandblasted. Is it ok to paint the inside when I paint the outside?
Thanks Tom

I always paint the inside of any engine I build with Rustoleum Clean Metal Primer (brushed on). Many of these engines I have torn down again after 200,000 + miles & it was still attached. When I was a kid, an old timer told me to do it because the oil travels faster back to the pan on paint vs raw metal. We were discussing racing engines & it probably doesn't much matter in a T, but I just do it out of habit 40+years later!

God Bless
Bill
https://www.jalopyjournal.com/forum/thr ... ed.614419/

Someone will surely chime in and say paint it with that "red stuff"...I can't remember what it's called,
but in my un-expert opinion I would say, "why bother"? It's gonna be completely coated/protected with
oil as soon as you first start the engine anyway and will stay that way until the engine is finé! Just my two cents!

Have used red Gyptol for many years on clean inside crankcases. Won't flake, and gives smooth finish for oil splash and drain out. Some bake it on, have just air dried and find it works just super for me.

And, coated the inside of the hogshead too, plus the underside of the inspection cover. Nice smooth finish for the oil to flow over.

You can see the thin oil film sheeting down the Gyptol finish

In 56 years I have never seen any reason to paint inside the engine but am open to new ideas. The folks that rebuilt my last engine did it and they should know.
Rich

Glyptal is also called insulating varnish. If you're buying it pays to shop around. Prices range from reasonable to preposterous.

How hot do you want your oil?
Something to remember is that a T has no oil cooler, it relys on heat transfer into metal to regulate temp, that red poo is a very high heat resistant paint. The hotter the oil gets. thinner it gets, thinner it gets the less hydromatic oil pressure for the babbit bearings you have. As far as I'm concerned, it's only good for modern oil pumped engines with a oil cooler fitted

I have never rebuilt a Model T engine, but have done many modern pushrod V8s. I have never painted the inside of an engine, and never will. I appreciate that the clearances on the T are not as tight as those on a modern engine, but I will not take the chance of a flake of paint getting somewhere where it shouldn't. With all of the oil splashing around do you think that rust would be a problem?l

I'm with those who say no. I can't really think of any particularly good reason to paint the engine inside, and I can think of a couple of potentially good reasons not to.

I am not in favor of painting the inside of an engine. As has been said, that may contribrute to some degree of losing some temperature advantage and I don't think there is that much advantage that the oil will flow down that much better. I think the risk of the coating coming off would be worse than if it wasn't there. I can't see that it would make that much difference on a T engine. JMHO Dave

I can see the gyptal (spelling? That's the red "goop" which is actually red insulating varnish ) being very useful on the inside of the aluminum hogshead, in case of casting porosity. Rolls Royce did this to their aluminum engine castings back in the 1920s & 1930s, if it was good enough for them, it ought to be good enough for the T!

If you are rebuilding an old cast iron block that is saturated with oil, there is no way I'd paint it.
If the block was new, I'd consider cleaning it and painting it to prevent porosity issues.
If the block was used, and thermally cleaned (baked) to eliminate any oil in the casting, I'd paint it.

Completely unnecessary and you're just asking for trouble.

Ford didn't paint them, and neither will I!

Painting mine, after sandblasting the bare metal will rust faster than when it was made new, also it may seal any particles of sand not removed from a post blasting cleaning operation. Castings used in farm tractors are routinely sealed at time of manufacture for the same reason contain any casting sand not recovered and also seal any casting porosity.

I wasn't going to post on this, because it is interesting to find out what is going on and why it is so. However, "It will rust faster" doesn't make sense to me. The oil coats the metal preventing rust. If you drive the car a lot, you will always have some oil splashed around the inside. I am neither for nor against painting it, just think it unnecessary to do so.
Norm

Norm, Sure motor oil will protect the bare metal providing you clean the rust off the pan, assemble the engine and put it service right away. Most T's are projects that take long periods of time from beginning to end, things like condensation can aid in the deterioration. While we are debating this subject in the amount of time required to do so will paint the inside of my crankcase, each to his own,