Hardblock & Glyptal
 

What are the prevailing ohpinions for Hardblock on the Street?, and Glyptal on the Block interior?

I did Hardblock on a 455 to the freezeplug & Water Pump holes lower edges: seemed fine except for sitting in traffic.

I had a spare 455 with glyptal valley and it looked high fidelity after a decade or so.

My Application: Iron head 421 for Lonngk Highway Cruise and Towing.

In terms of hard block and using a motor on the street I only fill to a little more then half way up the freeze plugs on the side of the block.

I use to use Gylptal all the time then I realized it was eye candy because getting block and or heads 100% clean by means of bead blasting is all that’s ever needed.

I mean if having a extra 4 tea spoons out of the pan and up in the heads will make for motor failure then you need to be looking elsewhere for oil related problems!

My engine is hard blocked up to the water pump holes. The oil will heat up on longer higher rpm drives. This was noticeable when i swapped to 373's. My advice for long drives or towing..install an oil cooler.

Related......

Taken in part from Jim Butler comments, Q&A section, PE magazine March/April 1997:

They built two engines for Rodney's '82 T/A street car. Both engines had 455 blocks. One was filled and the other wasn't. The filled block ran 10 to 15 degrees cooler than the unfilled block. It was reported upon tear-down and inspection, the cylinder walls on the unfilled block were seen to be scratched and scored from excess friction. When measured with a dial bore gauge, it was found to be out of round. The filled block was smooth and bore round. He confirmed you do not lose significant coolant capacity by filling the block. However, the difference in the amount of friction is much improved.


Ken Keefer (Pontiac Dude) recommended this product to me years ago.
A good product and easy material to work with.

Rokblock Professional Engine Block Filler
Designed to expand into all interior voids. Helps prevent cylinder wall cracking and keeps cylinder walls round which will improve ring seal. 98% cured within 24 hours. Will not separate from block, even after many years of racing.

https://www.competitionproducts.com/...oductinfo/rok/



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Why bother?

It’s just a moderately built 421 for a street and highway cruiser, why overcomplicate things with unnecessary work?

Reducing the capacity of the block water jackets seems counterproductive in this application.

From your original post: “seemed fine except for sitting in traffic”.

So I guess you already know filling the block wasn’t all that great.

2X Bman.Tom

Admittedly Gylyptal is for looks, but also for trapped particles that don't wash out, clean oil by virtue of varnish not adhearing to the red paint,

Hardblock not reaching the lower freeze plugs is intriguing, as it may not harm cooling while trapping any sediment that could otherwise free up.

And every Pontiac engine that rolled off the assembly line had neither of those mods and were fine.

We’re not talking race engines here, just cars people depended on day after day.

But of course you do you, personally I think it’s simply effort wasted that could be spent on truly useful things.

Well, if you do hardblock it you need to let it cure with some heads torqued down with the same type of head gasket you will run.
Let it cure for a long time too.
Don't think you need any of it though.

These thoughts nag at me, As i wait for suitable pistons. Will side with b-man to skip the largess.

Paint NOT applied to the oiled surfaces of the engine CANNOT flake off and plug the oil-pickup screen.

To me, honing with a torque plate is the most important block mod, on any application.

That is a misnomer.
Pontiac are not small block Chevies and Fords where you have 7/16 bolts and more distance between them and the bore.
Pontiac 400 and 455s have 1/2" bolts and they are real close to the bore.
So they distort more than .004.
That deal about the factory having extra iron around the bolts to help with bore distortion was just some ones idea that did not work.
They distort .006 a 1/2" under the deck, right where you do not want it to.
If you want your bores to be "round" you bore and hone with a deck plate.
If the machinists tooling will not allow that you bore them .010 under and ridged hone to size.

I've got two motors hard blocked to the water pump holes 400-455
And both run cooler with no problems 455 is a butler stroker motor.
Mine didn't heat more in traffic

GT

Yes to hard block half way on all my engines - and no to glyptol. Have a really nice 455 block aftermarket 4 bolt caps , w a lot of work done to it with flaking glyptol in my basement . Been there 20 years. Haven’t needed it but it’s a constant reminder to me not to use glyptol. Had to be swapped out before a race to a block without glyptol.

I've used Glyptal on Ford Model T magnetos with zero issues for years and years. The mag is on the flywheel and runs in engine oil.
I've also used it on Pontiac timing covers and water pump plates for years. It prevents electrolysis and corrosion. Never had an issue.
Have seen it used on the valleys of old hot rod engines in the old days, never an issue. Done to make oil return faster.
I've never had it flake off or degrade. It is NOT a paint. More like an insulative epoxy. But the surfaces need to be clean.

Well I can tell you the block I have was prepped properly and clean as clean gets when it was done . Glyptol was peeling a crazy and had to pull the engine before a big race and swap blocks . Not fun. This was a fresh engine with about 6 days of racing on it . Never ever would put that crap in an engine again absolutely zero need for it IMO.

Do the oil temps creep up?

On a related note.... Any suggestions for removing properly applied Glyptol?

I have the same setup with hardblock up to bottom of water pump holes. I am installing a Meziere Fan powered oil cooler and I'll have quite a bit of extra "outside engine" oil capacity with a 3 quart Accumulator, and a 4" Clearview Filter all with 12an Lines.