51 FL Base Gasket replacement

[Froger]

I run into that a lot. It seems the front base gaskets are beyond the makers' capabilities to produce accurately. Just modify the gaskets (and plates if needed). You can use a round jeweler's file or small chainsaw file, or scrape them with a sharp knife, Exacto, etc.

Your pics show the hole in the case in an odd place. the other alternative would be to chamfer the hole on one side to align it with the gaskets. Again, scraping with a sharp knife, and of course capturing any chips, would do it.

Jim

I started to file the holes carefully with a sharp point die grinder bit and will clean up with a Dremel metal bit all the while consistent blowing with air compressor to remove the Swarf ..

[Froger]

heard of Hylomar products?

Hylomar manufactures a wide range of high performance sealants and adhesives used by some of the leading OEM’s in the world of automotive, aerospace, white goods, power generation/distribution, electronics/photonics and general engineering.
Hylomar Aerograde, Aerograde Ultra and Advanced Formulation are specified by various aero-engine manufacturers; including Rolls-Royce and Pratt & Whitney.
Hylomar Aerograde is also specified by NATO."

https://hylomar.com/en/

No I haven't TriNortchopz I'll have a look into it ..
I have bought some Permatex Copper Spray A Gasket Hi-Temp Sealant Aero ...
Fred

[TriNortchopz]

I have bought some Permatex Copper Spray A Gasket Hi-Temp Sealant Aero ..

This may be of interest:


Copper Head Gasket Sealant Comparison

PLIOBOND CONTACT CEMENT darkens & hardens at 450 to 500F and loses integrity at 500 but still stays in place and when its cooled it remains adhered to the metal. Stays adhered at 400 F. An excellent sealer for heads.

Permatex copper “spray a gasket” high temp – starts smoking and loses adhesion at 400 F but stays in place and is still adhered when cooled.

K&W “Copper coat” brush on gasket sealer – loses adhesion at 400 F but stays in place and is still adhered when cooled...'

see more sealant comparisons here:

https://jsmotorsport.com/sealant-comparison/

[Froger]

This may be of interest:


Copper Head Gasket Sealant Comparison

PLIOBOND CONTACT CEMENT darkens & hardens at 450 to 500F and loses integrity at 500 but still stays in place and when its cooled it remains adhered to the metal. Stays adhered at 400 F. An excellent sealer for heads.

Permatex copper “spray a gasket” high temp – starts smoking and loses adhesion at 400 F but stays in place and is still adhered when cooled.

K&W “Copper coat” brush on gasket sealer – loses adhesion at 400 F but stays in place and is still adhered when cooled...'

see more sealant comparisons here:

https://jsmotorsport.com/sealant-comparison/

Good info on that site TriNortchopz....

[Froger]

Update on cylinders .. Have wire brushed all the old paint off the cylinders with a grinder back to shiny cast metal , then thought it would be a good idea to clean them in a mix of thinners and cleaning vinegar to take the residue off for the next procedure to painting with heat paint .. Unfortunately for the one I did it flash rusted straight away, so I've left the other one as is . Trying to work out what to clean the contaminate's from the wire brush procedure off without flash rusting it ...
I've seen some youtube clips claiming to use an epoxy primer straight over it over the clean cast metal with cleaning contaminant off the then paint it ... Hoping someone on done this job before and knows the secret to this procedure ..
Cheers

[TriNortchopz]

Trying to work out what to clean the contaminate's from the wire brush procedure off without flash rusting it ...

I used regular old white vinegar to de-rust steel parts, but since it is a mild adic, it needs to be neutralized with water, and I did not get it dried fast enough, flash rust happened.

i used rust convertors to cover and chemically change rust with good results;
"What is Rust Converter?
Rust Converter, a water-based primer, contains two active ingredients: Tannic acid and an organic polymer.
The first ingredient, tannic acid, reacts with iron oxide (rust) and chemically converts it to iron tannate, a dark-colored stable material. Tannins are a group of water- and alcohol-soluble natural products extracted from fruits, trees and grasses. The second active ingredient is a proprietary organic polymer that provides a protective primer layer. The overall chemical reaction converts rust into a stable, black protective polymeric coating that serves as an excellent primer for both oil and epoxy based paints..."

https://www.theruststore.com/Rust-Converter-FAQs-W48.aspx

I found a product that is a flash rust preventer; have not used it - yet:

How-To: Prevent flash rust on metal parts

"Anytime you get a bare metal surface wet, it will flash rust quickly. Not ideal…..EVER...
So the answer is pretty simple: treat the water with a flash rust preventer with a product like Holdtight 102.

This product removes contaminates and salts from the water not allowing rust to form. Supposedly protects the surface for 2-4 days..."

https://howtomotorcyclerepair.com/preventflashrust/

HoldTight®102 salt remover / flash rust preventer has set the standard of performance for more than three decades.
Removes all salts and contaminants
Prevents flash rust for up to 72 hours
Leaves no residue
Extends the life of coatings"
HoldTight® 102 can be worked into any blasting process to achieve a totally clean surface, with zero flash-rust and zero residue left behind.
HoldTight® 102 is a clear, simple additive with visible results, eliminating both natural and artificial contaminants."

https://holdtight.com/products/holdtight-102/

[Froger]

Thanks TriNortchopz good recommendation and info , I'll get onto it ..

[Froger]

I'm considering what size rings to use ,after I did a couple of light hones the bores now read 3.498 bordering on 3.5 .. The bore is obviously above standard 1200 it's closer to the 1340 bore size .. I want to put new rings in any one have any suggestions on what to use as at a bit of standstill as to what to use ...
Cheers
Fred

[Dragstews]

You're right at Std Bore for the 80" motors ...
(3-7/16" + 0.060" O/S)

The rings I'd order would be 0.010" oversize, that would allow for custom fitting the ring gaps ...

[JBinNC]

Hastings 6482 are the rings for 74 cu.in. pistons with 1/16 thick compression rings. So, for your bore size you need 6482 + .060, or 6482 + .070 if you want to file fit your rings as D. suggests.

Hastings 6127 are the rings for 80 cu.in. pistons and the standard size in that part number will fit your bore size, again with 1/16 compression rings.

For the moly filled top ring, you would want 2M6482 +.060 or 2M6127Std, these are the same rings under two different part numbers. Hope that is not too confusing.

Jim