My Alfa Romeo 33 rebuild - FIRST TIMER

[Brit01]

Well after a whole afternoon of measuring the main bearing shells, mixing them back and forth, ended up with the new Glyco ones just on the front bearing journal.
All now have a clearance of about 0.050mm.

2 of the old original shells had a better fit than the new Glyco ones. I expect they were the fattest of the 3 colours of the standard size.

Also another place with more than 0.2mm of play was the oil pump bypass valve (both on the shaft and seat)!!
Luckily I have a new one with no play.
0.2 mm is a lot of play and imagine I was loosing quite a few pounds of pressure here when hot.

Quick question.

I need to use gasket sealant on the front and back plates the block with paper gaskets.
I have 3M sealant.
Is is best to coat the metal sides or cover both sides of the gasket?

[Urbancamo]

If you define your 3M product more closer, we can tell you what kind of gasket sealant/maker it is and how it's used.

[Brit01]

I will have to try and translate it first into English. All in Portuguese.

The name is Engine Gasket Adhesive translated but the instructions a little it more tricky.

[timinator]

Hi Chris,

FWIW Permatex 80019 Aviation form-a-gasket is my favorite. Buy some rubbing alcohol(isopropyl) to remove it. Don't know if Uruguay stocks it.

[Brit01]

FWIW Permatex 80019 Aviation form-a-gasket is my favorite. Buy some rubbing alcohol(isopropyl) to remove it. Don't know if Uruguay stocks it.

Thanks Tim.

You use form-a-gasket along with the gasket? Didn't know this was done.
They do sell Molykote silicon gasket maker here.

I was lucky enough to find 3M sealer here. The only well known brand I could find.

Regarding the oil pump bypass valve, I was surprised to find so much wear on the shaft of the old valve pin. Last thing I would have thought of wearing down.
It wobbled withing its bore!! New one fits really snuggly.
~0.2mm difference between the new and old shaft width is quite significant I believe.

[timinator]

You use form-a-gasket along with the gasket? Didn't know this was done.
They do sell Molykote silicon gasket maker here..

Aviation Permatex is not silicon. It is more like pine tar, having it's origin from shellac. It has been around since 1915.

[Brit01]

Bit about the oil pump.
New original pressure relieve valve fitted. Gear clearance measured.
Old release valve as mentioned was badly worn and as you can see the area around the seat has much less contact surface area than the new one.

[Guy Croft]

"Is is best to coat the metal sides or cover both sides of the gasket?"

Does not matter - though I find coating the metal is easier than holding a sticky gasket! Using a couple of studs in the block to guide the gasket and housing into the right place is a good idea.

G

[Brit01]

Thanks Guy.

Yes you are right it will be easier to coat the metal surfaces. The gaskets I have are pretty rare also so the last thing I want is a torn paper gasket trying to apply sticky adhesive.

Luckily the block has studs on one side to guide the gasket and plate to attach.

Regards

Chris

[timinator]

Thanks Guy.

Yes you are right it will be easier to coat the metal surfaces. The gaskets I have are pretty rare also so the last thing I want is a torn paper gasket trying to apply sticky adhesive.

Luckily the block has studs on one side to guide the gasket and plate to attach.

Regards

Chris

This is probably going to raise some feathers, but. Put permatex on one side and lithium grease(white grease) on the other. It allows you to remove cover plates, intake manifolds etc. without tearing. If you use lithium on both sides the gasket will push out or just tear.

[Guy Croft]

Doesn't raise any feathers with me as you cordially put it!

Everyone has their proven method. The only ones I do not like are those that lead to tons of silicone or other sealant in the oil pickup trap like this Lancia oil pump I overhauled lately.

I only use sealant on coolant gaskets - where the surface condition of the mating parts is impaired by corrosion. On all other gaskets I wet them with WD40 before bolting up as it helps the gasket settle. You will realise that many gasket joints are what we call 'soft joints' and settlement can allow the bolts to loosen. Use of the right washer combo is vital. This does not apply to late generation thermosetting polymers used on head gaskets. Joints on engines like the Fiat SOHC and TC - with separate camboxes - settle a thou or two overnight and the bolts must be 'cracked off' and retightened next day.

The most advanced sealants have a minimal tendency to lose the edge of the bead inside the engine and decompose in the oil, like the Wurth product I have now adopted 'Super RTV Silicone' (black, code 0893 321 1) and that is super to work with and with the special nozzle supplied it doesn't 'go off' in the container.

G

[Brit01]

The most advanced sealants have a minimal tendency to lose the edge of the bead inside the engine and decompose in the oil, like the Wurth product I have now adopted 'Super RTV Silicone' (black, code 0893 321 1) and that is super to work with and with the special nozzle supplied it doesn't 'go off' in the container.

Wurth is one of the few products they sell here. But I have doubts that they have the 'Super RTV Silicone' unfortunately.
They do offer the standard Wurth brown cement that hardens like a rock I believe.

I hope the 3M adhesive is not one of the ones that loses the edges of the beads inside the block.

[Brit01]

Made some good progress these last few days despite the drought and 30+ degree temps. Bit on the hot side to be lifting blocks/heads/cranks and torquing up nuts!

Crank in, pistons in. Front and back plates on.
Flywheel on.
Heads on today and other bits.

[Urbancamo]

Chris, that engine is like a pan cake for sure!

Good progress there, can't wait to hear results from this pretty massive overhaul.

[TomLouwrier]

Nice.
You eat your lunch off that Chris?

regards
Tom