painting inside of iron blocks.

[fekbmax]

Anyone still painting the inside of there blocks with GLYPTAL ?
just a curious question. Some old schoolers swear by it. Others say its a waist of time. Like to know what some of the pro engine builders here think. I got a can on the shelf.. should I use it ?  Id be worried about adhesion no matter how well its prepped and cleaned. Never used it before except in actual electric motor housing for the blowers in the cooling tower.

[machoneman]

No pro builder here but....

In the day, many racers did use Glyptal, as I did, and so did a lot of race engine shops. But, if the theory was to smooth the surfaces of cast iron for the faster return of oil to the pan.....why not merely smooth the valley and other unmachined areas with a cartridge roll, stone or other grinding tool? Btw, most aluminum parts are so smooth the painting likely does nothing. High mileage intended street engines should also skip the paint job as they are more prone to stripping, over time, unlike a low running time race engine.   

I'd say skip it 100%, smooth all areas one can reach, especially remove any casting flask and sharp edges, on FE's be sure to enlarge the head drainback holes and call it a day.

[Autoholic]

What about ceramic coatings like jet hot? I could see a benefit in coating the valley to try and keep heat away from the intake.

[blykins]

I don't (and won't) paint/coat anything inside.....

[machoneman]

What about ceramic coatings like jet hot? I could see a benefit in coating the valley to try and keep heat away from the intake.

I believe a sheet metal shield, used by many automakers on production engines to do just that, would be more beneficial, and easily much cheaper. Btw, here's the same BBC (sorry!) oil shield we ran long ago; as one can see it does nothing to retain lifter bodies nor is it bolted in, merely snapped in. Its purpose was solely to prevent oil from hitting the bottom of the intake manifold, keep it cooler and preventing the coking of oil into that crusty mass one sees sometimes inside an engine.

http://paceperformance.com/images/F29408136.jpg

[chris401]

Smoothed out the valley on my last one with a grinding wheel. Occasional 6,000 shifts and occasional 100 mph+ with 4:10 axle and 6 qts of oil the oil gauge never stumbled.

[Barry_R]

No interior paint here at all.

A risk taken with no reward...

[Autoholic]

Thanks, I had completely forgotten about the shield. What is the opinion then about coating the whole intake? Should you avoid coating the bottom? Ceramic coatings have been beneficial on exhaust headers.

[machoneman]

The intakes I've seen ceramic coated had them done to change the color (say purple or red to match the exterior of the car) and/or to keep fuel from staining the somewhat surface-porous aluminum casting. I don't think most if any do so for hp gains, minimal that they'd likely be. Cost/benefit, as stated by our pro builders here, comes into play.

Besides, an intake must have some level of heat to maximize fuel distribution especially in carb'ed applications. Even iced-down intakes, done just before a drag-race, do retain a lot of heat, at least compared to ambient temps.

Would be interesting to know if sprint and NASCAR spec. engines, due to heating over a long race, use said technology on intakes and valleys....I have no idea. 

[Autoholic]

I could see an inconel heat shield being useful but high temp ceramic coatings would be smart to keep heat soak to a minimum. Yes, most often you see people painting the intake for aesthetic reasons. But if you wanted to go with a protective coating, instead of just chroming it, you could ceramic coat it to help. You face heat soak more often than lack of heat in the IAT, especially in a pleasure vehicle that normally isn't driven in the cold. In warm weather, you're trying to get the IAT as low as possible. So the bigger issue is heat soak.

[Nightmist66]

I like to use Glyptal on many things. Inside the engine I like to use it to seal the cast iron surface so no tiny particles come loose, keep it from rusting, heat isolation on intake, and sheds oil too. Here's a few snaps of our windsor (sorry) project. Didn't have time or energy to get all the small areas around bottom cam tunnel and main webbing, etc.





Inside the heads too


An imprtant note if using this is make sure you bake it somehow to make the most of it. I just use a heat lamp for several hours. I also painted the inside of my third member and housing while I had it apart.

[Autoholic]

Who here knows from personal account of glyptal flaking off? I know paint can flake, hell just about any surface can flake too, even smoothed surfaces.

[machoneman]

n/m

[machoneman]

"Like to know what some of the pro engine builders here think."

Two pro engine builders said no dice.....are we beating a dead horse now.

http://www.network54.com/Forum/74182/thread/1390228684/Red+Primer+on+Inside+of+Engine

Brent has seen it stripped (see his old post) and so have I.

[Joe-JDC]

I painted the inside of my 428 CJ back in 1981 when I freshened the shortblock with a .030 overbore, and it still looks like it did then.  I just had the block freshened up with a torque plate hone, and will re-assemble everything with new rings, bearings, gaskets, etc.  Block prep and cleanliness before application are key to longevity of the glyptol.  Joe-JDC