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Please have a look at the photos.
My RB30 block has couple of badly pitted spots between the water gallery & fire ring.
One in cylinder 1 and one in Cylinder 6.
Now, I know this block needs decking, but it is NO option for me due to time constraints.
So, is there a way for me to ensure the head gasket will hold these two places without leaking
combustion gas into the water gallery or vice versa for next twelve months or so??!!
I'm thinking below products applied thinly on to the head gasket or the pitted areas of the block as in the pictures.
I'm also open to the ideas of any metalic/epoxy sort of product where I can thinly apply onto the pitted area and sand/polish until flat. It is a desperate situation so I might need desperate and outside the box thinking and solutions.
Other than these couple of pitted areas the block surface is ok(afaics) & no warping of the surface either.
Any ideas, thoughts no matter how crazy they are will be good and appreciated.
Thanx
Dom
P.S. Below are the high resolution photos in google photos.
What has that piston crunched up? Are there score marks in that bore?
The broken pieces of the carby base/inlet manifold directional cup thingy got sucked into the cylinder 6(obviously) and scored and nicked few places.
You should see the damage it did to the cylinder head combustion chamber surface. It damaged the edge near the fire ring as well. Check out below. It's something you gonna have to worry about soon as well. It is a common occurrence with carby RB30's.
In my case, it was most likely responsible for head gasket fire ring damage and the leakage between the water gallery & the combustion chamber.
Back in 2015 when I started hearing the rattle and found out it was the broken directional cup thingy after removing the manifold, I opted not to lift the head even though I didn't find all the broken pieces in side the manifold. Most blokes here advised me to lift the head and clean the combustion chambers but I gambled and didn't do it & paid the price.
Last edited by dom14; 16th October 2017 at 10:44 PM.
What has that piston crunched up? Are there score marks in that bore?
Cylinder 6 walls are fine(afaict).
I advise everybody with an RB30 carby engine to remove the damn directional cup thing.
Whatever the reason Nissan engineers put it there ain't worth it 'cos of the damage it can do the pistons, head and the bore.
Last edited by dom14; 16th October 2017 at 10:48 PM.
DOM, for me I think this needs machining, end of story. You say you 'have time constraints' but do you have the time to do the job twice, plus the cost if the 'back yard garage fix' fails? You could be in further pain than you are now with additional damage.
I come from a machining background and comments like, 'its flat etc' validated without accurate measurement equipment are risky. I would get the head wash ground and verified as 'flat' within whatever tolerances are acceptable, and then have the block mating surface machined as well, again to within established tolerances. Your machinist would need to assess it if the pitting exceeds the allowance on both items. Get them crack tested and be done with it, put it all back together and drive it.
If this was the only block and head in existence on some rare as rocking horse motor, and conventional - as above methods - were not avail or possible then i guess a 'bog it up' method might be all you have, or if you are stuck 500klm up the scrub and just want to get it home, then the 'instant metal 'style of repair is justified. I have seen it happen all too often that a band-aid is applied, then requires a bigger bandaid etc until finally the penny drops and you tear the equipment down and fix it - understand for a breakdown but perhaps not this repair - just my thoughts.
DOM, for me I think this needs machining, end of story. You say you 'have time constraints' but do you have the time to do the job twice, plus the cost if the 'back yard garage fix' fails? You could be in further pain than you are now with additional damage.
I come from a machining background and comments like, 'its flat etc' validated without accurate measurement equipment are risky. I would get the head wash ground and verified as 'flat' within whatever tolerances are acceptable, and then have the block mating surface machined as well, again to within established tolerances. Your machinist would need to assess it if the pitting exceeds the allowance on both items. Get them crack tested and be done with it, put it all back together and drive it.
If this was the only block and head in existence on some rare as rocking horse motor, and conventional - as above methods - were not avail or possible then i guess a 'bog it up' method might be all you have, or if you are stuck 500klm up the scrub and just want to get it home, then the 'instant metal 'style of repair is justified. I have seen it happen all too often that a band-aid is applied, then requires a bigger bandaid etc until finally the penny drops and you tear the equipment down and fix it - understand for a breakdown but perhaps not this repair - just my thoughts.
Thanx mate. I agree with all the above.
I'm beginning to get sick and tired of this thing after finding more and more things to fix and don't have the time for it right now.
If I can get it patched up at least for couple of months I can tackle it again later this year or early next year.
And, yes, I won't attempt any big trips with it.
I'm googling "Instant Metal" or other bogging up material.
Let me know if you know more about that stuff, brands, where to get, etc etc.
I am using the term instant metal as a generic term for any manner of synthetic metal repair products that claim to have long term repair properties. I carry a couple of different types with me including a very high temp one, will have to look it up for you but I don't know how you get a surface flat once you apply it, or at least flat enough for an application like your. Stay tuned, back shortly.
I know JB Weld has a metal repair putty stick with similar properties, but not sure whether it comes with a smooth finish. If the finish comes out porous, it won't do it.
I won't know until I try it for sure.
Last edited by dom14; 17th October 2017 at 12:11 AM.
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Originally Posted by mudnut
