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Cylinder head swap
https://forums.tipec.net/viewtopic.php?f=25&t=8199		 Page 1 of 1
Author:  AndyG [ Sat Mar 27, 2010 8:43 pm ]
Post subject:  Cylinder head swap
Hi all,

Just to recap, last year I swapped my engine with one off of ebay, as my original was starting to suffer from bearing failure. That went resonably apart from the the "new" one had a crossed spark plug thread. I've been driving it around like that for the past year albeit carefully. So now the weathers cheered up I thought it was about time to sort it.

I took the head off my old engine and had it refurbished (£217). I've spent the day today trying to swap it. Its not gone to badly, the only dramas being, trying to get the thermostat out. You need the patience of a saint and a good pair of circlip pliers. Also the camcover to cylinder head hex bolts must have been done up by Geoff Capes, which resulted in one being round off, nothing else for it but to drill it out. Fortunately it was one of outside ones so no worries of getting swarf in the engine.
I'm now at the stage where the new head is torqued down, so hopefully should be able to finish off tomorrow. Although paranoia is now kicking in, did I clean the faces enough?, have I dropped anything down the oil galleries? will it ever start again?

I was wondering should I change the oil anyway? The thing is its not that old. Also I noticed that the breather pipe does take in a fair bit of oil and dumps it throughout the inlet manifold and the engine, this can't be doing the engine and performance much good. Is it worth fitting a breather tank?
Author:  J.J. [ Sun Mar 28, 2010 8:19 am ]
Post subject:  Re: Cylinder head swap
You dont have to drill out the cam box bolts. They are serrated on the outside so you can bray a 3/8 drive socket over the outside. Forget the size & get them out that way! Works on the internal ones as well but you have to grind the socket down a bit to fit through the hole.
Breather may need cleaning out as they bung up. If the engine has had say a cooler seal failure in the past. Often cleaning the breather is missed. You can just disconnect the thing & put a small filter on but you may get oil fumes in the cabin. I wouldn't bother changing the oil until it's due so long as you drained the coolant first. There should have been no contamination. Doing the same job myself as the first time the head wasn't done well enough. It only lasted 12 months. £200 is too cheap for a proper overhaul. Generic valve guides cost nearly that. Hope you were lucky & the original ones were good. Fingers crossed. :)
Author:  zola1 [ Sun Mar 28, 2010 12:43 pm ]
Post subject:  Re: Cylinder head swap
Hi Andy,

Did mine back in the summer of 08, here's a pic of the cyl/head after i had it skimmed (could'nt go much further approaching the minimum deck height !...whats your like ?

cheers
Author:  AndyG [ Sun Mar 28, 2010 8:12 pm ]
Post subject:  Re: Cylinder head swap
Hi

Nearly there, just the inlet manifold and a few other bits to go!

I'm glad you noticed the cost, It was a bit bitter/sweet. I took my original head into the garage and asked them to do a decoke and pressure test which they told me would cost £60 +vat. Great I thought, as it came off a working engine I didn't think it would need much. They would call me if they thought it needed anything else. The weeks went by and I then called them, they said it should be the of the week and never mentioned anything about the head needing extra work, and they would call to confirm. No phone call, and I happened to be passing the following week and popped in. They told me it was ready and gave me a bill for £217... "eh? What happened to the £60+vat"
They had skimmed it, relapped the valves, put in new oil seals as well as the decoke and pressure test. Which wouldn't have been a problem if they had phoned me up and asked me but they didn't!
After a bit of a stand off, they pointed out they had only charged me 1 1/2 hours labour. So to be fair it was a good price for what they had done, if only they could learn to communicate.

zola1 wrote:
Hi Andy,

Did mine back in the summer of 08, here's a pic of the cyl/head after i had it skimmed (could'nt go much further approaching the minimum deck height !...whats your like ?

cheers


Yep, thats pretty much what it ended up looking like, don't know how far they went, the conversation kinda went in a different direction :roll:
Author:  AndyG [ Mon Mar 29, 2010 5:23 pm ]
Post subject:  Re: Cylinder head swap
I can't quite believe it but its back together and it works! :shock:

The only thing left is bleeding the coolant, which is proving a bit of a pig. I let it run with the bleed screw out but with the temp. gauge at the top I didn't want to leave it to long. I wish I'd noticed Fortyfoursupertwos' pressure bleeding idea first, I'll give this a go tomorrow.

I'm over the moon that it actually goes as I've never taken the head off anything before although I'll leave the champagne on ice until I give it a proper run. TBH if this had not gone well I was seriously thinking of terminating this ownership! But hopefully now I can go on and complete the rest of the restoration :D
Author:  tr7v8 [ Mon Mar 29, 2010 5:47 pm ]
Post subject:  Re: Cylinder head swap
Glad to here it at least runs. Don't let it get too hot otherwise you'll cook it. If you really struggle to bleed it jack the front up as high as it'll go & see if that helps. Squidging the hoses also helps the air work itself out. Also I assume you have the heater wide open?

This may help:-
http://forums.pelicanparts.com/porsche- ... edure.html
Author:  zola1 [ Mon Mar 29, 2010 6:11 pm ]
Post subject:  Re: Cylinder head swap
Good effort Andy well done,

The only thing left is bleeding the coolant, which is proving a bit of a pig. I let it run with the bleed screw out but with the temp. gauge at the top I didn't want to leave it to long. I wish I'd noticed Fortyfoursupertwos' pressure bleeding idea first, I'll give this a go tomorrow.

I manually filled the rad from the top hose then connected up a pump up coolant pressure tester and forced the air out the bleed vent, still took a while to get the air out, lots of patience mate take your time as Jim said don't let it run too long on high temp turn off and let cool a bit .

hope this helps
Author:  Richy_S [ Mon Mar 29, 2010 6:23 pm ]
Post subject:  Re: Cylinder head swap
I might be wrong but thought the bleed screw should only be opened when the engine is not running as it can suck air in. Bled these many times and never had an issue - squeeze the hoses with your hands to help force air out.
Never ever had to let the car run hot to bleed it.

I would always change the oil - cant see how you can clean the top of the block without getting any contaminants in the oil but thats just me.

How you doing Derrick? its been a while.

Rich
Author:  AndyG [ Mon Mar 29, 2010 9:27 pm ]
Post subject:  Re: Cylinder head swap
Thanks Jim, thats a good thread, lots of different ideas. I was just using the Haynes manual, which only has the method I was using.

I should point out I never let the temp. gauge get over the top white line.

When cleaning the block, I put rags in the oil holes to avoid contaminating the oil. I was more worried that coolant could get in when removing the head. If any did get in would it evaporate off?

Thanks guys
Author:  tr7v8 [ Tue Mar 30, 2010 1:48 pm ]
Post subject:  Re: Cylinder head swap
AndyG wrote:
Thanks Jim, thats a good thread, lots of different ideas. I was just using the Haynes manual, which only has the method I was using.

I should point out I never let the temp. gauge get over the top white line.

When cleaning the block, I put rags in the oil holes to avoid contaminating the oil. I was more worried that coolant could get in when removing the head. If any did get in would it evaporate off?

Thanks guys

It should evaporate off but it still makes the oil deteriorate. Depends on quantity TBH, but I'd change it fairly soon.
Author:  zola1 [ Tue Mar 30, 2010 9:15 pm ]
Post subject:  Re: Cylinder head swap
Richy_S wrote:
I might be wrong but thought the bleed screw should only be opened when the engine is not running as it can suck air in. Bled these many times and never had an issue - squeeze the hoses with your hands to help force air out.
Never ever had to let the car run hot to bleed it.

I would always change the oil - cant see how you can clean the top of the block without getting any contaminants in the oil but thats just me.

How you doing Derrick? its been a while.

Rich


Hi Rich,

Good to hear from you, i'm ok, your car looks nice.
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