Jump to content

The Impostor - 3.0L Rebuild


Recommended Posts

Hi All, 

I hope you don't mind me starting this rebuild thread.  Please let me know as I'm happy to delete it.  As you can see, I don't quite have a Porsche but have already found so much useful info on here and was hoping to share my first engine rebuild.  I'm happy for people to suggest recommendations and help me to understand.







So a bit of history. Bought as a shell that was imported from Arizona to UK back in 2010. Fully restored and painted and fitted 1981 SC engine - completing in May 2012.  Travelled 2500miles to South of france for a holiday before a friends wedding in July 2012 and another friends in December 2012.  Moved to Melbourne for 2yrs back in April 2013 so left the camper in storage for our return.  4yrs on the wife and I decided that we would ship the camper over to Aus as it's the ideal place for enjoyment. Started the prep for VASS approval and RWC only to find a snapped headstud on exhaust side on no.6.  Historically I have had lower compression on no.2 so I've opted for a rebuild before getting her on the road.

The engine is now out and on the floor - with a bit of help from the wife!  She's been promising for the past 12yrs to help and finally volunteered to give us a hand! AND SHE ENJOYED IT!

A bit of prep before work starts:





evidence of the wife:


separating the box from engine:


I await the arrival of my engine stand mount before getting it on the stand.  I'm going to carry out a leakdown test before the teardown.  Not sure whether there's much point though as I'm stripping it down to a short block anyways.  The plan (at present) isn't to split the case but time may tell otherwise.  I'll be replacing all 24 headstuds with standard steels and will inspect parts for condition as I go.

Link to comment
Share on other sites

Thanks for the kind words guys.  It wasn't what I was expecting to have to do when I decided to ship her from the UK but needs must and this forum looks like a real great place to share and learn along the way.  I was 80% happy with the engine install first time around so hopefully I can make a good dent in the 20% I wasn't that happy with.

Link to comment
Share on other sites

Thanks again for the response guys.  I'm glad you're happy for me to document it all here.

While I have been stripping the engine down to a longblock while on the floor and awaiting the arrival of my engine mount, I have been thinking.  My original plan was to carryout a leakdown test before tearing the engine down to a short block to get the leakage numbers.  I realise that this should be done on an engine that it up to operating temp.  however, the fact that the engine had been sat for 4+years without being run, I didnt want to run it simply for the purpose of the leakdown test only to strip it down anyway to replace the head studs.

Again, the fact that I am stripping it down to a short block whatever the numbers, do you see any point of doing this test? especially if its not reliable due to not being a warm engine. If the results are going to be unreliable would the results at least likely be consistent between cylinders?  What you your thoughts?

Link to comment
Share on other sites

My thoughts are not to bother but take the following approach instead.

Considering it is going to be apart, why not test the valve seats in the heads by poring some petrol in each chamber?

If you come back in an hour / next day and the level is the same - happy days, if on the other hand wet inlet/outlet, then consider a quick home lapping or indeed off to a machine shop. Personally, I would do this as a matter of course and install new rings 'while you're there' ;) 

Link to comment
Share on other sites

Thanks for the kind words guys.  It wasn't what I was expecting to have to do when I decided to ship her from the UK but needs must and this forum looks like a real great place to share and learn along the way.  I was 80% happy with the engine install first time around so hopefully I can make a good dent in the 20% I wasn't that happy with.

Is that tunnel photo in Cardiff? I see the van's reg is from South Wales....

Nice Kombi btw ??

Link to comment
Share on other sites

Thanks p-kay great advice.

Haha. Get out of town! Yes it is!!!! Butetown tunnel.

It was when it was the cover feature of Volksworld Magazine!

I lived in Cardiff bay for several years. How come you know it?

Thought as much :lol:

We lived in Penarth for the 5 years prior to moving here in 2011. First moved to Cardiff in 1994 (Roath) while my wife did her PhD at the Heath. Butetown tunnel was a daily occurrence ?

Link to comment
Share on other sites

Haha, small world.  We lived in Adventurers Quay in Cardiff Bay from 2011 until 2013 when we moved out. Not sure whether you had a Porsche when you were in Penarth, but I used to take the camper to a friend of mine Dave, who owned RS Porsche on railway terrace.

Edited by NaFe
Link to comment
Share on other sites

  • 3 weeks later...

So things have started a little slower than planned. So slow that It looks like a couple of other rebuilds have cropped up on here :)

So the engine 

K-Jet setup lifted in one go and shelved for later:



Engine mount arrived and borrowed crane from a mate:


distributor shaft: Wear isnt too bad is it?


nice and dry :)


Oil cooler is a bit beaten up, but not sure its leaking? is there a self pressure test method or is there somewhere in Melb that can test?:20170907_190919_zpswkib2ygh.jpg20170907_191954_zpsob0cng5l.jpg20170907_192015_zpsucu8g0xw.jpg

Managed to start removing the cam chain covers which I'll hopefully finish off over the weekend. the Right hand cover was pretty stuck so a soft mallet was gently use to loosen the cover from the gasket.

Link to comment
Share on other sites

Was hoping to make some good progress over the weekend, but I mis-read Wayne's book and didn't order myself a 46mm crowsfoot wrench for the removal of the cams, so only managed to remove carrera upgrade oil lines and cam covers.

O ye, and a bit more oil that was left in the engine when I rotated it a little ;-)




Damn my bloody kayak for spoiling the view!

I've got a crowsfoot on order...along with a few of the other tools I'll be needing along the way

Link to comment
Share on other sites

  • 2 weeks later...

Had a good couple of hours on the engine teardown yesterday.  Before I removed the cam towers I fit fitted the bolt into the end of the cam for cam sync using the Clewett Engineering cam sync setup:

Historically I had low compression on no.2 and found that one of the exhaust headstuds didnt have much torque left on it when i removed it.  When I have previously tested compression i had around 85psi on no.2 and all others were around 100-105psi (efore the headstud issue on no.6 that is.  clear leakage on no.2



no. 6 with its snapped headstud showing clear leakage on exhaust side also



LHS cam assembly (no.1-3) 



RHS cam assembly (no.4-6)



would you say this is excessive carbon buildup on the valves?  The engine has had several known periods where is hasnt run for couple of years:



This is what I'm down to as of yesterday:


Link to comment
Share on other sites

Well if nikasil you got lucky.  I'm not an expert but my understanding is Alusil should be removed as a unit and p/c not separated if you want to use again.  Happy to be corrected though.

Well I jsut had a 5min check in the garage and Wayne's book suggests that the coating of the Nikasil cylinders are slightly magnetic.  Low and behold they are magnetic!!!!

Initial conclusion is that they are therefore, Nikasil

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...