Hey Guys,
The cylinder head that I'm rebuilding atm is pretty dirty as in the picture.
Can you please suggest some el cheapo cleaning methods/cleaning chemical?
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Hey Guys,
The cylinder head that I'm rebuilding atm is pretty dirty as in the picture.
Can you please suggest some el cheapo cleaning methods/cleaning chemical?
take head and slab of beer to local cylinder head/enginereco shop. trade beer for putting the head through his hot tank.
short of that, completely dismantle and with a large container several stiff bristly and wire burshes start scrubbing with petrol, on tough spots try brake cleaner or acetone
but its a really shitty messy job so really recomend the above method, the simple fact is you are going to need a shop to crack test and surface the head anyway so may as well let their hot tank do the dirty work
Hot tank as above. Even if they charge you its only gonna be $50-$80
I'm super tightarse atm I wanna get it done for couple of peanuts. :DQuote:
Originally Posted by nissannewby
I'll be crack testing it myself with a home made gadget. I'll be 'machining' it myself using a homemade setup as well. Only thing that will stop me DIY at home will be the cracks. If there are any cracks, then I won't have time to muck around trying to repair cracks backyard DIY method.(But, I will be attempting it another time. :D )Quote:
Originally Posted by billyj
Cheers :D
Ok im curious, Unless you have a mill sitting in your shed how are you going to accurately machine the head?
Just like the way demonstrated in below short video.Quote:
Originally Posted by johno90
https://www.youtube.com/watch?v=mc_gaGAf2pk&t=48s
For a six cylinder, you will need a thicker glass with a slightly stronger table. A piece of thick glass you can pick up for nothing online.
Just make sure the glass is flat using a metal ruler and a feeler gauge, both before and after fitting the glass on the table.
It's a kinda bench sanding setup you can use for many other projects, not just for the cylinder head machining.
This guy uses a flat piece of sanding block made out of thick flat piece of plastic or veneered MDF, etc, but I prefer the above glass table method 'cos
it uses the weight of the head and also the whole head moves against the sanding table, producing a more accurate flat machined surface with less physical effort.
https://www.youtube.com/watch?v=HyKN52HD6RU&t=42s
https://www.youtube.com/watch?v=SK2R2LdkLKs&t=1152s
Only thing that cost me money was the few sandpapers & the glue to stick the sandpapers onto the glass. Thick glass and table was picked up from the side of the road from somebody's hard rubbish.(One person's rubbish is another person's treasure, I guess. :) )
The above cylinder head surfacing method using a glass table is pretty easy thing to do with cylinders heads upto 4 cylinders. Six cylinder ones are slightly heavier and longer, but still doable without much dramas. The glasses are usually perfectly flat, but you still wanna make sure by using a ruler & a feeler gauge on it. And of course use the ruler and feeler gauge on the cylinder head once the machining is finished to make sure it's come out good.
You'll be amazed that even the visible cracks can be repaired using JBWeld. How long that fix would last is something I don't know as I haven't done it yet.
But, it's been successfully done on motorbike and other small engine cylinder heads.
Cracks can be patched up with TIG aluminium welding as the professionals do, but you need to be good with TIG welding.
Grinding and polishing can be done with grinding/polishing bits with an air or electric grinder/drill.
I have seen that video and seems to work with an aluminum head, would that technique work with a cast iron one?
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Yea glass works with cast or alloy, have done it in the bush before but ill promise you that you will be blowning gaskets after 15,000km easy or less!
Its not only about the surface being flat but the texture and cut pattern also come into it - a good example is different bore hones and grades to suits what rings your using.
Good on you for giving it ago but for the $300 it would take to hot tub it and fly cut it, its not worth all the hassle and future repairs.
Do it once properly otherwise it will cost more anyway!
You can use fine grit sandpaper that costs next to nothing. If the gaskets blowup at around 15000km, then something's not done right.Quote:
Originally Posted by johno90
For additional insurance, you can use a product like below.
https://www.autobarn.com.au/vht-copp...et-cement-sp21
Make sure to spray it on the gasket, never on the head or block. Let it dry for ten minutes or so before placing the head gasket on the block.
You can use a WD40 or something similar to get a superfine smooth surface(spray it on the sand paper), if a superfine smooth surface is a concern.
People have done it with heads upto 4 cylinders with success. I am yet to find out the success with my six cylinder head, but I am pretty confident.
Yes, I used the same table(with gritter sandpaper) to machine the stock exhaust manifold. It came out pretty good.Quote:
Originally Posted by Rossco
@dom14
Trust me I've built many engines from 4cyl through to 12cyl. Im not saying it wont work im saying it wont last.
Here is sorter the point Im making, there is alot more to metal work and gaskets and building engines then people think - its why a proper built engine is always expensive
"Don’t go smoother than 40 Ra (240 Rz) or rougher than 100 Ra (600 Rz) with a gasket. Rougher surfaces limit gasket conformance, while smoother surfaces increase the tendency for gaskets to flow, reducing the gaskets blow out resistance."
What ever you do dont spray the copper on anything other then a standard compo or paper gasket, spraying on mls or anything else is actually doing it harm.
Just trying to give you some experienced advice :) and save you money in the long term.
Thanx for the tips. Yes, I can't argue with that experience as I haven't been rebuilding engines on regular hobby basis.Quote:
Originally Posted by johno90
Yes, I can understand the surface smoothness of the head need to have some perfect balance to match the particular head gasket. Too coarse or too smooth both can yield unfavourable results as you explained above.
Yes, I understand there is no saving in money if the head gasket fails within few thousand km's of engine running.
And yes, I can understand there is a difference between sanded metal surface and machined metal surface with a cutting tip.
The surface texture of a mill machine cut surface would have curved cut lines whereas sandpaper ground surface would have straight lines.
I guess for a particular type of head gasket, those surface texture pattern can negatively or positively affect.
Of course, there is no way backyard engine rebuilding can match with proper machine shop work.
It is fun to DIY and it's even more fun when I get it right.
as above even most composite gaskets are pre coated these days, spraying them with copper coat or hylomar etc will only reduce how well they adhear