Fixing a BHG, Need advice on preparing block

[doobs]

Ey all,

Just a quick question, Using a standard head gasket, on a 7MGTE, how well should I prepair the block surface? I have used a can of gasket stripper on there (3 times over), and cleaned it as best I can, but I still have the graphite marks on the block from the previous gasket.

The surface feels flat when I run my nails over it and theres no scoring... ill post a pic up soon, but if anyone has pics of there blocks that were prepaired by hand at home, and some methods I could use, please post them up

Cheers Fellas

[EldarO]

Ey all,

Just a quick question, Using a standard head gasket, on a 7MGTE, how well should I prepair the block surface? I have used a can of gasket stripper on there (3 times over), and cleaned it as best I can, but I still have the graphite marks on the block from the previous gasket.

The surface feels flat when I run my nails over it and theres no scoring... ill post a pic up soon, but if anyone has pics of there blocks that were prepaired by hand at home, and some methods I could use, please post them up

Cheers Fellas

JustCallMeFrank a.k.a Nathan i beleive used a sharpening stone or some such device, basically, he wet down the block, and rubbed the stone over it and it took off minimal material, amking it all smooth.

keep in mind, the better you prepare it now, the longer it will last, if you do it to the best of yuor ability, it should last through anything you put it through.

if your in doubt, get a shop to do it, at least the head, to make it as good as possible, getting the head skimmed should cost less than $100.

Another overlooked part, check your water galleries for corrosion, as most people just reaplce the gasket with corroded galleries, then wonder why it blows again, the corrosion further reduces the distance between the gallery and the cylinder, and makes it even easier to blow.

if yours isnt TOO bad, you should be alright, however if the corrosion is a bit much, theres no real point in doing it without getting the head reco'd at the same time, because it most certainly will blow, well, have a higher chance of doing so anyway.

Eldar.O.

[Mr DOHC]

just get a decent quality gasket screper and make sure it is razor sharp, {like i found out one day when i slid mine up my arm and shaved it bald }
and just scrape it VERY well, thats all that necessary.

dont let any of the shit go down in the cylinders/galleries either

[30psi 4agte]

another way is to get a scotch-brite pad and scrub it clean if you already have the majority of the gasket off!

This should bring the block up sweet with a bit of elbow grease

[sam-131]

ah softish wire brush and wd40 and 1000 grit wet and dry is the king for preping make sure it's smooth and clean like a babys bottem or clean enough to eat off

[doobs]

Thanx fellas, I have had the head machined, its almost a mirror finish.

I used a sharp 1" chisel on the block and the CRC gasket stripper. That has removed all of the gasket. I blocked all the "holes" when I remeved the remanace of the gasket.

Im worried that if I use a wire brush/scotch-brite pad it may score the block... IAnd the wet and dry might make the block "unflat". How can I aviod this... so WD40 will be the best "lube" to use when cleaning?

Cheers

[30psi 4agte]

if you use a scotch brite by hand you will not have ANY probs !!!!!!!!!!!
dont worry about having a little bit of a "rough" finish this can work in your favour when it comes to sealing the gaket.

some ( all good ) machine shops actually leave some portion of the fly cut on the block insted of being babys bum smooth cos of this

i am talking about minute portion just trying to say its not a mirror finish

[sam-131]

i found that yes wd40 or some form of cleaning lube worked best

as for making the block unlevel i take it that 7m's are cast iron so you would have to be there for a long long time to do any harm really nothing to much to worry about

edit:ya main problem is making sure that it's as clean as clean can be to insure hd sealment (is that even a word) what ever just make sure it's not dirty

i was always told that some form of ruffyness is good not to ruff but like a slightly etched if you get my vibe

[doobs]

Thanx for that dude, and it is cast iron, My house mate has a old 7m block, might test it on his if its ok...

+1 rep for all

Cheers, if anyone has pics of their results please post.

[Mr DOHC]

if u make the surfaces smooth as humanly possible then the gasket wont seal, ther isntr any "bite"

so if u go over board u may be enhancing the "poo-goodness"

[doobs]

sort of damned if i do and damned if i dont...

[Bananaman]

I wouldn't be too worried about actually taking much metal off sanding away, i'd be more worried about marking something with the chisel. I've used roughish paper on my old fj40 engine when i was cleaning up stubborn gasket crap and never had any dramas

That said, the motor in that thing probably weighed more than my whole ke20

[Smokey228]

hey, wen there is corossion through the motor. how can u clean it out?
ive got crap all the way through my 1ggte water galeries. is there anyway i can get it out? i mean, there was even shit in the thermostat housing wen i removed it. not corosion, but powder i assume from the BHG...??

thanks in advance...

[sam-131]

i had the same problem with my fiat motor i am building a screw driver a long basted at that and an air compresser with a blower nozle is the best solution just scrap all the crap then flush out with the air works a treat

but if the engine is still in the car try runing some of that engine flush then just go hard with the hose. flushing out the rad and engine make sure you turn the water pump when flushing and de-thermoize it(de-thermoize is a process of removeing the thermostat and flushing from the drunken mechinacis language) it might take a few goes flushing but you'd be surprised how much shit builds up

[Bananaman]

I will never use that coolant system cleaner shit EVER again. I used it in the fj40, must have rinsed it out 5 times, and there somehow was still traces of it in the bottom of the block or something. Which i found out when i drove 10mins and blew the headgasket.

Just be careful, make sure you drain the block as well, and try to rinse it out as best you can. Its frothy shit.