Dave does a DIY cylinder head pressure test and skim. Back together, with video

[DodgyBastard]

Here's what a cracked head looks like!

 

DSC_0235 by srblythe, on Flickr

 

DSC_0234 by srblythe, on Flickr

 

DSC_0232 by srblythe, on Flickr

 

DSC_0231 by srblythe, on Flickr

 

DSC_0230 by srblythe, on Flickr

 

DSC_0229 by srblythe, on Flickr

 

DSC_0228 by srblythe, on Flickr

 

I think you can zoom in if you follow the links to flickr.

[twosmoke300]

Cracks around the pre combustion chamber on an idi diesel are common and nowt to worry about .

[holbeck]

Good work dave. 

 

I do like seeing a bit of clever improvisation.

 

I presume the next step is the lead squashing to get the right gasket thickness for your 'skimmed' head?

 

 

 

<<tangent>>

Years ago as an apprentice in a Diesel engine factory, I had to pressure test part machined cylinder heads. 

 

The rig used looked remarkably like what you knocked up.

Head clamped down on a thick piece of rubber then hand pumped with bright green water up to a pressure that was a green band marked on a gauge.

 

The failures went straight in the foundry melt furnace.

[oldcars]

Super work indeed. 

[OwdChina]

Cracks in heads can sometimes be a bit of a fucker to find. This is the head off the Marty McFly truck and all looks normal except the two center chambers are clean due to water in the combustion chamber. I'd already decided that because a new head is cheap for these 22re engines it was getting a new head regardless, but out of curiosity a buddy in a machine shop (who was thinking of selling it) tested it.

 

 

Pressuring it up revealed a crack between the valves, barely visible to the eye...........between the two felt tip lines.

 

 

As the engine warms the crack enlarges and this blew the gasket (which was past its prime) into the next chamber. Best of luck with yours, I hope it is OK.

Oh.......do you have a cat fitted, it may be borked, cats don't like antifreeze.

 

 

[dave21478]

No, it was blowing combustion gas into the coolant but not drawing coolant back into the chambers....no sign of steam cleaning in the cylinders and the exhaust wasnt noticeably steamy. 

Im pretty confident that this head will be ok.....worst case and its still leaking due to an undiscovered crack...I can pull the head (or even the whole engine) from the Mazda although I would prefer not to and keep it as a backup vehicle.

I have found a seller on ebay Germany selling brand new bare heads for 200 euros and ready to fit ones with valves, cam etc for 350, so thats an option too.

[OwdChina]

^^Ah good....sounds like you'll be OK then.

 

That is not too far away from what I paid for a new head.......$330 delivered. If you do go down that route then get the one with cam, valves etc. already fitted..........it saves a lot of pissing about and everything is new.

[dave21478]

Aye, I would go for the full head as lapping valves is a PITA and I loaned my valve spring compressor to someone ages ago and never got it back.

[dave21478]

easy enough.....

 

 

And no, I dont know why the last few minutes is upside down - sorry. Neither do I know why its been transformed into potato-vision.

 

 

 

Anyway, it took a bit of cranking to get fuel through to the injectors and it spluttered into life and seems to run fine.

 

There is no insurance on it, so best I could do was an illicit wee spev up to the farm and back, but all seems well for now.

 

 

[Noel Tidybeard]

\o/

[tooSavvy]

\o/

( )

]^[

 

Joyous Fat man, in wellies

 

 

TS

[dollywobbler]

Huzzah! This has been quite the adventure. Definitely gold star material here.

[Uncle Jimmy]

Excellent bit of work. Frankly I'd rather do a job like that myself anyway, I no longer trust that it will be done properly, usually I scare em a bit when they realise I know what I'm talking about; like the other day when a bloke informed me that aluminium 'doesn't rust' and 'never shrinks'.

I've used the glass trick to surface cast iron joiners planes; it works best on surfaces that a concave, not so good on convex surfaces as you can inadvertently rock the workpiece. I also like to blue up the surface- or use a big marker pen so as you can check progress. If you're a proper canny bastard you can try using a straight edge, feeler gauges and an engineers scraper.

[Eddie Honda]

informed me that aluminium 'doesn't rust'

It doesn't. It might oxidise or corrode though.

 

Rust is exclusively for iron oxide.

[dave21478]

The temp gauge was creeping upwards and there were wee guffs of steam from the grill.

 

fffFFFFFFUUUUUUUUU......

 

 

Before I threw myself under the next passing truck I had a poke round the engine bay and the bloody radiator had a pinhole leak. Wobbed it with araldite and it seems to be holding fine and the temperature is behaving itself again.

 

This is why I didnt want to fix it on my sisters drive in Scotland....God knows how far down the A90 I would have got before it cooked itself again.

[Guest Hooli]

I'll be surprised if araldite lasts there, I tried fitting a temp sensor with it once. It fell out every few weeks.

[dave21478]

i ARALDITED THE RAD ON THE fREELANDER AFTER i TORE A COUPLE OF ELEMENTS IN THE MIDDLE OF IT AND ITS LASTED WELL OVER A YEAR NOW. uSE A dREMEL TOOL WITH A STIFF BRUSH AND SOME KIND OF SOLVENT CLEANER TO PREP IT FIRST AND IT STICKS REALLY WELL.

 

gah, fuck you, caps lock. I aint re-typing that.

[Guest Hooli]

Cheers, I'll remember that next time then.