I finished fixing the old TP up a few weeks ago, fixed leaking coolant from timing cover and elsewhere, new chains, replaced valve stem seals, etc. She seemed to be running beautifully for a while, but was only doing short runs around the place. On the weekend we went for the first long run, and started losing coolant, overheating, leaking oil. I just finished taking the head off just now. The oil leak was mainly from that port in the head that is blanked off by the EFI inlet manifold, the gasket was stuffed. What did that port used to do I wonder, another obsolete port? The coolant was leaking from the port closest to the water pump, next to the number 4 cylinder. The block and the head has corroded around that port, but there is enough flat surface left to get a good seal. So my question is can I patch up the corrosion on the block and head with some quicksteel, which says it has a continuous operating temp of 260*C. Also, while I think of it, all of the high compression seal between the cylinder bore and head, comes from that steel lip on the head gasket, doesn't it? I hope so, becuase there's very little gasket between the number 4 cylinder and the corroded coolant port.

use the ploy blue in a spray can all over both sides of the head gasket


Have to have a look again at this coolant hole location to be sure

EFI may not need it if it is blanked by the head gasket

Factory manual says to use sealants

inlet manifold
you use i use permatex blue around the water/coolant ports both ends

oil sealant for oil chanels

and the ploy blue in a spray can for the rest of the inlet

got a pic of how its is done will post it up later

For starters, you never use silicone on an EFI engine with a cat.....

YOu use a good quality head gasket, the head should be ok depending on the amount of corrosion, you may need to get the area welded then agian is cheaper to just grab a second hand head and get that one shaved as you will need to with this head either way.

Do not use anything on the head gasket, they have coatings that will bond provided all surfaces are correcly prepared.

With the block, get a chunk of wood, say 4 x 2, wrap and attach (i use some flat head nails from the sides) to it, some 60 or 80 wet and dry is ideal, using a back and forth circular motion evenly go over the entire block. Use wd40 or similar to lubricate.

Inlet, use no3 aviation cement around the oil hole and the water holes, prepare the manifold same as the block. no need to seal the inlet gasket around the inlet ports, this can acually cause the gasket to fail under vacuum.

The hole was where the mechanical fuel pump went on the carb models, was something that mits never bothered to get rid of, not sure why really, poss because of the carb triton and the carb mazda ute which used the same motor with a manual pump

silicone promotes rust and should never be used on any car in my opinion. my 2cents

this is out of the TN factory manual

nothing wrong with using products on the shelf
holymar blue gasket sealant its worth reseaching

http://www.hylomar.co.uk/universalblue.htm

if you belive you have a head gasket problem

use that straigh edge and feeler guage tip to determine where the warpage is on the block

silicone promotes rust and should never be used on any car in my opinion. my 2cents
There are different types, some are acidic, and cause rust. I would guess the ones designed for cars and gaskets are perfectly fine on cars.

<snip>
holymar blue gasket sealant its worth reseaching

http://www.hylomar.co.uk/universalblue.htm



Interesting link, thanks mb. So is universal blue the spray on poly blue you mentioned earlier?

There are different types, some are acidic, and cause rust. I would guess the ones designed for cars and gaskets are perfectly fine on cars.

silicone is not a sealant for cars(show me one that is and i will be quiet). it use for repelling water on gutters windows etc etc
somthing like rtv sealant should be used there's a whole range of rtv from zorst to water pump housing and gasket sealant as well even a sealant that is a gasket maker. if it was me id take madmagna's advice and only use a gasket joiner like hylomr (blue sticky stuff in a can).

Interesting link, thanks mb. So is universal blue the spray on poly blue you mentioned earlier?

thats the stuff i was reffering to im my post, have a can next to me.it's just use for joining the gaskets up . being sticky the gasket wont slide around but should not be use in place of a sealant!!

Okay, were thinking the same thing then smooth2. I consider all those products made fro cars, that look like silicone, smell like silicone, and tastes like silcone, as types of silicone. They don't call them silcone, but I think they are a special type of silicone. No, of course you don't use the gutter type silcones on cars.

after checking for warps
old gasket cleaned etc

ever since I used this stuff I have never had a problem

with a head gasket sump or any other gasket sealing

spray both sides wait a bit then lay the gasket on :D

I do use a smear of stag now for water corrosion reduction

permatex black for motor oil

this stuff is no good on the exhaust gasket

I would need to see a picture of the block before saying

if the quicksteal can be used .. where you say the problem is

on your block ...it is made out of mostky cast iorn then you are bolting to it aluminium

I have used the product before but in different places on a motor no problems

http://www.hylomar.co.uk/universalblue.htm
lists all its promised aplications and possibilities

been using it in the workshops for engine overhauls/rebuilds for years now ...same with permatex black and blue where needed ?

trouble is you dont get to keep the gasket if you need to take it off again after the car has been running

the gaskets bonds so well ,,,,you have to go buy another

Any head gasket, with exception to a shim style should not EVER be re used once the head has been torqued!

The product above is sensational on a copper based head gasket, on a properly installed mono torque style gasket it will do little more than the sealant that comes coated on the head gasket anyway.

As for sealants, it is really each to their own, on my race engines, I simply used aviation no3 on all cash iron and alloy surfaces and grey (similar to the blue, oly looks better :) ) on all pressed tin such as sumps etc.

One trick with sumps is use the aviation cement no3 on the block, timing cover and on the other side of the gasket use the grey (where contacts with sump)