Does this 7m still have life in it? (56k warning!)

[kemicalx]

Ey guys,

As some of you will know, shortly after purchase of my mz21 Soarer the head gasket blew in it, and it a very inconveint time, which meant i had to leave the car with the BHG dormant for several weeks.. anyway, finally have time to get stuck into it and heres what i've found.




A bit of rust and no carbon build up, which according to the head guy i took it to said meant it had to have got damn hot and is 99.9% likely to have warped would be very expensive to reapir.




Headgasket appears to have blown out on cylinders 1 and 6




Two tone oil drained from sump, not exactly a great sign.






Bottom end isn't looking all that healthy, at least from the top. Will know what the internals are like when i get a block and tackle to help remove it from the car. I'll get some more photo's when i get that done.

What do you guys think? Does any of it look useable? I'm trying to reduce the cost of the repairs as much as possible, without cutting corners.

Thanks everyone,
Ashlin.

[emp?]

that looks well worn
is there much lip on the top of the bores?

[oldcorollas]

to start, disassemble head, take it to head shop for cleaning and ask them to measure if it is flat.

go from there.... a lot of that rusty lookin stuff will just buff out but you need to distinguish superficial damage from bad damage...

have fun!!

[thechuckster]

in the mean time, spray everything that's rusting with some WD40 (or similar water repeling oily stuff) to prevent further corrosion.

With any BHG, there's a risk of warped head - but the minimal carbon buildup is from the steam cleaning the head got when the gasket first failed. You can see how piston #1 & #6 now have clean tops from the steam.

It's not a sign of massive heat - total loss of coolant and pitted/melted piston tops is a sign of excessive heat.

Suggest you clean and strip down head (important: mark which valves went where) take head to a machine shop to check for straightness. Just tell them you think engine got a 'bit hot' and gasket was starting to leak - mentioning that you had massive BHG will trigger them to automatically charging you for a straighten-and--skim.

In the mean time, pull block down and get the wear measured.

[M.J.H]

The cheapest you will get out of this job will be Rings,bearings,timing belt and a head service.
If it was mine i would just give it a freshen up with the above parts and a light hone to clean up the bores.By the look of them you could use them for a mirror before the rust set in.
Good luck with it all, Hope you have it going again soon.

[kemicalx]

Thanks for all the help guys

Yep presuming the head and bottom end are still useable the head will be getting a good clean over and skim, i'll leave the valves in when i take it to another shop as i don't have a spring compressor and they could use a blasting anyway.

The cylinder walls although messy don't seem to be scored anywhere, so if there isn't any major damage when i rip it down i'll have the surface decked definatly hone the walls and replace the rings/bearings

Which bringss me to another Q. How much would chromium piston rings and new bearings set me back?

Cheers everyone

[whatthe?]

The cheapest you will get out of this job will be Rings,bearings,timing belt and a head service.
If it was mine i would just give it a freshen up with the above parts and a light hone to clean up the bores.By the look of them you could use them for a mirror before the rust set in.
Good luck with it all, Hope you have it going again soon.

Actually, the cheapest you will get out of it is to buy an import engine for +/- $1000 and whack that in. Just torque the HG down to 72lb first!

[kemicalx]

i don't have $1000 unfortunatly, i would have loved to buy that crate motor John had for sale a while back

I'm sort of looking at this as a chance to learn how to rebuild a motor, and although it will probally cost more than buying a new motor outright, i'll (hope to god) end up with a nice healthy motor that will take the mild power mods i'll add, a good knowledge of how to fix anything that might go wrong in the future and finally some more tools to add to my slowly growing collection

[whatthe?]

i would have loved to buy that crate motor John had for sale a while back

Same, believe me, still kicking myself for missing that one! Good luck with the build-up, hope you can get away with everything for under a grand (and post up what you did if you can! enquiring minds want to know)

[ed]

fwiw: that actually looks in reasonable nick. aside from the deposits in the water galleries (which will wash out) there is minimal corrosion of the jackets in both the head and block.

it will obviously need a bore and hone, but with basic machining, thatll actually be very reasonable (and ive seen inside a LOT of 7Ms)

cheers
ed

[kemicalx]

thanks ed that gives me a bit of hope
I will be taking the head to another reco place tomorrrow. Get them to test it and hopefully give it the all clear so it can be cleaned up and resurfaced

[RyleyMA61]

and i realise it's probably the obvious, but make sure you get the head and block surfaces machined dead smooth, to an almost mirror finish as allan and others have said many times-

the chuckster is on the money too getting the head checked for warpage and hairline cracks.

it cost me $1300 for someone else to replace my headgasket, which included the reconditioning of my head, (machining, testing for cracks, new valve seats etc), stock headgasket, aftermarket bolts and labour. i had it run-in well too, and has been fine ever since!

g/l with it mate.

[EldarO]

Actually, the cheapest you will get out of it is to buy an import engine for +/- $1000 and whack that in. Just torque the HG down to 72lb first!

Im paying $1400 for my 7MGTE + Gearbox, will be here in January, fresh from the land of the rising sun.

Eldar.O.

[mic*]

Can someone explain why the cheapest fix is gonna involve a new timing belt, rings, and bearings?

Looking at your oil, this car got put off the road immediately after it BHG. There is no emulsion whatsoever. The water and oil havent even mixed well for the 20mm or so in the middle of the bucket.

If you want to do it 100% guaranteed you would overhaul your bottom end, but there are plenty of BHG's that get water through the oil and end up back on the road better than ever (higher comp?) without going over bottom end. I wouldn expect to find anything at all wrong with your bottom end other than some superficial oxidation which will be nothing to worry about at all if you machine your head, clean the bores, get it back together & change your oil after it runs hot, and then again a few times in the first couple of thousand k's.

Since the tight budget seems your biggest limiting factor I would allow for;

-Get the head bathed, valves re-seated, and machined. (you could do the valves but for bugger all difference in charge just get it done).
-VRS kit. Never bought one for a 7M, but they came out in an MX83 aussie cres so should be much cheaper than a 1J or an RB25 kit for example.
-Oil & coolant
-Your time to carefully (painstakingly) clean the bores - without pulling it apart and machining it.
-Your time to re-fit the head.
<$500 + time. Not as guaranteed as bottomend overhaul - you get what you pay for.

The next step id be taking right now is, clean the block face & check it for warps... I think the result of that investigation might help u decide what to do.

[mic*]

...oh,

how long has the sump been drained/dry for?

In my book, you get out the cream (which there was none), then fill er back up & swish it round a bit if your gonna keep it.

oxygen exposure = oxidation, funny that.