WTB: 944 Plastic Oil Pan Baffle Insert

[Timm]

If any one has one, please let me know.

[Buchanan Automotive]

Hi Timm , as you have seen  by looking at your'e old plastic sump baffle, like all high temp oil resistant plastic's used in all  engines from all makers , they have a finite life span ,meaning they will fall apart/crack etc etc after so many heat cycles & years
 

We never ever reuse an old plastic sump baffle, same goes for 2nd hand ones ( same thing really ) , because its job is too important & because they are available new from Porsche , I know if we fit a new one its going to be at least another ten years of high oil temp cycles( track work ) before this new one comes apart , or in the case of a road going 951 you can make that 20 years 

Remember , the higher the oil temp , the quicker things like this( plastics / nylon ) will simply deteriorate & with you wanting to get a 951 engine onto the track to do some "Clug Supersprints " etc in the future , then we know for sure the oil temps are going to be higher than what these experience in just road driving ( that applies to all cars )

Replace with new one , anything else is false economy 

Regards

Bruce Buchanan
Buchanan Automotive

[Mike D'Silva]

He makes a good point.. I don't even know what this item is, but the advice still sounds spot on.

[Timm]

Yes that is a good point Bruce, I will try to find a new one.

This new one on ebay seems to be priced reasonably, cheaper than Lart's used baffle.

http://www.ebay.com.au/itm/944-968-New-Oil-Pan-Baffle-94410738903b3d-/182057918133?hash=item2a637f5eb5:g:-FQAAOSw-W5Urv1R

It's a late baffle though, I have already ordered a crank scraper from Paragon, do you know if the scraper will interfere with the plastic scraper on this baffle?

Or should I buy it anyway and try trim either the baffle or the scraper to suit?

 

 

 

[Buchanan Automotive]

We do not use crank scrapers , so I can not comment , we only use the standard Porsche oil baffle ( NEW ) via our local Porsche dealer ( Via Porsche Cars Australia )

Sean's big HP 3.0L 16V 951 engine has no dry sump , no crank scrapers , in fact the entire lower section of Sean's 3.0L 16V is stock standard , except conrods & pistons

Same goes for Mark Bloxhams 3.0L 8V  951

Both the above 951's are regularly doing better track times than GT3's in our PCNSW , in fact Sean was running racing slicks for one year or so ( 3 or so years ago )& Sean's 951 engine never had one oiling issue ( even with race slicks ) & even I thought this was pushing the envelope a bit too far , but it was fine , thats because slick race tyres give extra grip in corners ( extra G force ) which will normally cause chaos in a wet sump oil pick up ( road car ) design

This is the 10th ( Tenth ) year Sean has been competing in the PCNSW Supersprints & Motokhana's and has won multiple Drivers Championships & Motokhana Championships & his 951 engine's ( be it 2.5L in the old days ) or 3.0L since & neither of these two engines have ever suffered the dreaded No 2 conrod bearing failure ( that is the biggest fear )

As I have mentioned before , the secret to engine reliability is knowing how these engines work & what works well with them ( knowledge of 39 + years working on Porsche engines )

Regards

Bruce Buchanan
Buchanan Automotive

[Timm]

Correct me if I'm wrong, but I believe all the late oil pan baffles on turbo's and 16V cars have an inbuilt crank scraper? So installing one on your cars would be redundant anyway.

I'm only pulling about 1.2G's at the moment, hopefully a little more once I get some better tires...but I am still trying to do everything I can to avoid having any oiling issues. I already do the main things that you and others recommend: big oil cooler, heavy weight oil with high zddp, and I don't sit at high rpm for too long. Also a little mechanical sympathy goes a long way...I don't drive like a halfwit and rev my engine all the time or do burnouts or flog my motor when it's cold. I also keep my eye on the oil temp gauge on the track and do proper cool down laps after every heat. With my big oil cooler, oil temp hasn't gone much above 100 degrees which I believe is within ideal operating temps.

Anyway, I wonder if I can cancel the crank scraper from my order, as they are out of stock at the moment and are delaying the shipment. If I buy this late baffle, I am already getting half of the factory scraper anyway.

[Buchanan Automotive]

Hi Timm , no thats not correct , no 944S2 or later 951's have a crank scraper from Porsche genuine( these are aftermarket only ) , are you confusing that with something else ?

Regards 

Bruce Buchanan
Buchanan Automotive

[Timm]

Well I noticed that some of the plastic baffles and also the late oil pans on ebay are a bit different and have a different part number. I found a thread on rennlist which shows the differences between the early and late pan, and among those differences is an integrated crank scraper. The plastic baffle on ebay I linked above is one of the late versions with half of the crank scraper. The other half is incorporated into the oil pan.

http://rennlist.com/forums/944-turbo-and-turbo-s-forum/341799-i-m-still-confused-about-updating-an-86-oil-pan-baffle.html

You can see it in these two pictures:

Early Pan

Late Pan

I figured that if the factory added those in the later cars, then I should get an aftermarket bolt on crank scraper. Now I'm just not sure if the bolt on aftermarket scraper will interfere with the half of the factory crank scraper that is on the plastic baffle that I want to buy. Upgrading to a complete late oil panel would be too much of a hassle as the postage would be expensive, and it would also require the late pickup tube.

[Buchanan Automotive]

Timm , that is not a crank scraper , its just the later style oil baffling , the top photo is of a NA Early 944 sump with early sump baffling , has nothing to do with any 951 , a crank scraper ( like the ones on Paragon ) are connected to the engine crankcase 

Regards

Bruce Buchanan

Buchanan Automotive

[Peter M]

Bruce,

If that wasn't intended as a crank scraper, why would it be notched for connecting rod clearance?  And why would it be angled off the centreline to presumably aid drainage into the deeper part of the sump?

Just asking to understand.

[Buchanan Automotive]

Because it doesn't go close enough to the crank counter balance weights & its in the wrong position( its a nice update from Porsche but not much more ) , if you look at the one Paragon sells , that is much more closely  associated with a crank scraper , don't get me wrong , there is nothing wrong with them , its just application selection , for example all our 951 engines produce max usable power at lower revs as compared to modified NA engines we do ( but thats a different subject ), so in the case of 2.5 & 3.0L 951 engine's Sean builds we have no pressing need to install crank scrapers

Now , lets get back to BASICS , first off all , hands up all the people out their who had their or have heard of 951 engines ( 1986 , 1987 , 1988 , 1989 , 1990/91 ) ,944S,  944S2 , 968 engines ( and early 944 engines as well ) that on the track ( club track stuff ) that in the last TWENTY years + have blown their engines to BITS( No 2 conrod journal let go ) with the later style Porsche oil baffles & sump casting baffles ?  , YES the ones shown in the lower photo 

Answer } Crap Loads , in fact thats all you ever read , year after year after year after year , be it on Rennlist or at our PCNSW .   So here we are saying that all of a sudden the later style oil baffling is the answer , because some one thinks its a bit like oil scrapers  , when these engines have been blowing their bottom ends apart for over 20 +years 
Another 944S2 engine blew its bottom end apart ( PCNSW ) just a few months ago & completely preventable , that is what I am trying to get through , This Unnecessary Engine Destruction is Preventable & most of it is from too low oil viscosity & already damaged conrod bearings & also con rods that are too old ( metal fatigue )

So lets take take a look at what is needed in building a reliable 951 engine for club sprint work

A) Crankshaft has to be perfect & I mean PERFECT , I have lost count how many cranks I have thrown because they do do measure up exactly how I want it , but they look OK to the naked eye 

B ) New high quality aftermarket con rods & we use the standard Glycol bearings ( but thats our option )

C ) All cylinders have to be perfect and if needed new Wossner ( oversize ) pistons & rings ( crankcase bore to suite)

D )  On the 2.5 only , I am not very happy with the free standing cylinders that much , if the budget permits we get a deck plate made & installed, with the 3.0L this is much less of an issue because of the Siamese'd  cylinders the 3.0 has

E )  Metal head gasket & if the budget is OK then in conjunction with the deck plate we install / machine for top of cyl O rings

F )  On the outside of the engine , it will have large oil cooler/s mounted in nose cone & on this subject it will have an oil temp probe installed in the sump to measure oil temp at all times  & on this subject ( Oil Temp )  the Oil Temp will not go over 125 - 130 deg cel , meaning we want oil temp of around 105 to 110 deg cel

G )  Crankcase Ventilation ( MEGA important ) , mod to you're hearts content 

H )  Oil Viscosity , this is probably the most important & has been the demise of these last century engines than anything else , so lets go through it in a basic way 

For Ambient Temps of between minus Ten deg Cel ( - 10 )  to Unlimited high ambient temps  , the MINIMUM Oil Viscosity will be 25W-60 , we use Valvoline 25W-60 racing oil & with every 4 litres installed the engines receive 1 bottle of STP Blue ( we are after MAX Oil Film Strength ) with that viscosity
Now this is for our convenience so we can have oil viscosity that we can start the engine cold & drive the car to the track & compete on the track

If we were doing longer events than supersprints ( 4 / 5 laps ) then the oil viscosity would go into the traditional last century straight 50 racing , but you have to know how to deal with this & we are not going into that here ( no need )

----------------

Now onto options ( budget permitted ) 

First off the rank would be dedicated dry sump & yes this means the 951 in question is now a non street registrable car & is now a track car , but you can not beat proper dry sump set up , but on road cars its not going to happen

But Sean's & Mark's 3.0L 951's are street registrable cars & they have wet sump & it works , and has worked for a decade in Sean's 951 because of the above , are they are quicker than most if not all GT3's in the PCNSW  that are also street registrable , in fact I think Sean's 951 is quicker than one or two of the more race / non registrable GT3's & not just that very reliable & easy to maintain ( fraction of the cost of a GT3 ) 

Regards

Bruce Buchanan
Buchanan Automotive
 

[Peter M]

Thanks for explaining your reasoning Bruce.

[Timm]

Ah thanks for clearing up my misconception Bruce. I have not seen a late style pan up close and didn't know that what appeared to be a scraper is just different baffling.

I will buy the late oil baffle off ebay, and I will also install the paragon crank scraper. I've already paid for it, and I don't see any harm in putting it in.

On the points you have outlined regarding building a reliable engine, I think I have most of them addressed apart from crank ventilation and a deckplate. The deckplate is out of my budget but I want to look into crankcase ventilation. I will do some thread searching on Rennlist to see what people have done in regards to this...are we just talking about a catch can install? Are there some key guidelines you could share on your crank case ventilation modifications please?

I will have the machine shop check over the crank when I give it to them for a light polish, is there anything I should pass on to them that they should look out for when checking over the crank? Or just that the run out and all the journals are within specs?

 

 

[Buchanan Automotive]

Hi Timm , the principle of a crank scraper is quite OK & the one Paragon sells is good value for the money ( for what it is ) , now for it to work it must get as close the the end of the crank counterweights ( all of them ) as possible without touching & it will help in reducing the oil that is being spun off it being entrained in the windage cloud & naturally very high revs makes it more important 

Now with the NEW genuine Porsche "plastic" sump baffle 944 107 389 03 ( from memory ) , do not trim anything from it , just install it & make sure its NEW

With the crankshaft , the big thing we often find is in relation to previous episodes of humans getting into the big end journal/s area over the last 30 years ( Thirty Years ) and using fine emery to clean up a slightly marked journal ( usually no 2 )  & they have over done it by just a bit , so when we measure the conrod journals , 2 out of 5 cranks are out of spec , mainly No 2 , because of previous human activity , meaning no 2 crank journal is ever so slightly smaller then the others & for a road car only this can be still OK , but not OK if the engine is expected to function at the track with more output , because all that is going to happen is at high oil temp ( oil much thinner ) oil pressure at the slightly smaller journal will be less & this will destroy no 2 conrod bearing  ( basic physics ), and when it happens you will none the wiser because the journal will be mashed & you will never find the exact reason , so as you can see there are two different worlds in engine assembly 

One world where the car is just a road car and the crank spec is ever so close to being OK ish ( borderline )& will be fine for just road work & much less expense to the owner because we are just doing an engine refresh & reseal & will have only a modest increase to performance & road work only & the engine strictly being kept on a 20w-50 high oil film strength oil , then I know it will be fine

The other world is where the owner is keen to go to the track ( club supersprints etc ) & the crank is border line , forget it , the crank will be discarded & another good 2nd hand crank is found , measured & if perfect then we proceed & naturally we get the owner to supply the other 2nd hand crank & keep suppling until we get a good one 

Now onto something you will never think of until its WAY too late & thats the sump gasket ( Very Thick Black Nylon ) & how its installed , at fist glance you will see each hole in the thick sump gasket has an alloy spacer ( lots of holes & spacers ) & as you may of seen from the old one you have removed 
The new one is thicker than you think & you will without thinking refit the sump and install the bolts & keep tightening until the spacers bottom out & the bolts are now tight , well if you do that you will split the sump gasket in two in several places & you will be completely perplexed by it 

We install ( when ready ) with a high temp RTV sealant on both sides & even the M6 bolts gets the RTV so when we finally NIP the bolts to their last LOW torque figure , the silly short spacers do not bottom out at all internally , so in essence the sump is glued to the crankcase by RTV & the bolts are kept in place with the same , its up to you to choose the RTV & how munch is used or how little
Now the thick nylon sump gasket is also ( in the future ) a warning device if you do NOT get you're crankcase ventilation correct , so in other words if the sump gasket is inspected after one day at the track & you can see the sump gasket is being pushed out ( sideways ) then you know you are not controlling the crankcase gases ( excessive pressure build up in crankcase ) and this is very bad & it naturally wants to push out engine oil seals / cause oil leaks etc & oil smoke from exhaust , where as on the road only the need of an well thought out fabricated catch can is NOT needed at all 

On a very regular basis one must check the tightness ( nip ) of the sump bolts because the thick nylon sump gasket over time & heat cycles will crush & this leaves the sump bolts very loos to the feel , they are to be removed one by one & each thread hole in case to be cleaned out with a solvent ( that dries & is blown with compressed air ) & the M6 sump bolts surgically cleaned & re RTV'd  

Where as on a road car we might do this once only ( say 12 months later ) and thats that , but on a 951 that goes to the track , we do it at least 3 times a year  = maintenance 

Now, crankcase breathing on a 951 that goes to the track & that is also a road car = COMPROMISE , everything is a compromise when we have a fast road car & a decent track supersprint car , the two worlds do not mix well
 

The only decent compromise we have come up with is the following}

A )  The Catch Can has to be as LARGE as possible & has to be mounted as HIGH as possible  ( not down low , it just does not work )

B )  We have not come across anything on the market big enough in all the areas , meaning the capacity & size of fittings that we want / need so we ( Sean actually ) fabricates the one needed as per required per car out of sheet alloy , curves/ bends & Tig welds together with large male fittings so we can easily screw on large dia oil breather hoses ( Eero Quip Style) and we have two inlets to the catch can ( mounted up as high as possible ) & one outlet to go to the original ( in principle) air intake system 
      The large catch can must be easily removed to be drained & or seperate drain hose installed & the very important inlet hoses to it ( LARGE dia ) will be coming from }
            1) the original plastic catch bottle ( top ) but the top of the outlet has to be opened up as much as possible
             2) the second large dia hose will be coming from the top of the cam box , so in the case of the 8V engine we remove one of the allen headed alloy caps & screw in a fabricated "L" connection , sometimes we have used the 928S4 breather "L" connection , but these are no longer available new ( the type we need )

I can not overstate the importance of a LARGE catch can and mounted up high with LARGE inlet & outlet hoses to and from & like I have said , if you get the crankcase breathing wrong all you will get is oil leaks & oil smoke out the exhaust pipe 

Note } I am writing this from home as I am recuperating from a Hip replacement a week ago & this email has taken me around 9 hours to do on and off ( gives me something to do to pass the time away )in between other things 

Regards
Bruce Buchanan
Buchanan Automotive

[Peter M]

Bruce,

Why do you think they made the standard sump gasket so thick and elaborate?

Have you had any success leaving the gasket out completely and just using a bead of RTV?

Thanks

Peter

 

[Buchanan Automotive]

Hi Peter , the thickness is important so the oil pick up screen is at the correct depth in the sump , plus at there front & rear of the sump the alloy sump is rectangular convex , or put another way , the sump gasket in these area's have to fill a large rectangular groove which has to be filled 

But overall , the thick sump gasket is very longed lived in road conditions , usually 20 + years oil leak free & relatively easy to replace with steering rack & subframe removed , its actually a good design , one just need to know what it is 

And if installed well ( SEALED ) it even lasts very well in Track / Supersprint conditions & gives warning signs if you get the crankcase breathing wrong , so in essence its very valuable to keep as is 

Regards

Bruce Buchanan
Buchanan Automotive

[Timm]

Cheers for the extra tips Bruce. I wish you a speedy recover from the surgery.

With the crankshafts, is there a reason to not turn the journals down to the next undersize journal so you can use oversize bearings? Surely that's still cheaper than throwing the crank out and looking for another. And on that note, next time you throw a crank out, can you please let me know so that I can scavenge it out of your bin and keep it for an offset grind

Yes I noticed my sump gasket was installed with a whole lot of sealant and a lot of the bolts were hand tight at best...so I will be adding that to the maintenance list of bolts to check over regularly. I'll be sure to take my time installing it and not overprotecting any of the bolts.

I will also look into sorting out a decent catch can along the lines of what you describe, so thanks a bunch for the advice. You mention opening up the top of the aos, how much are we talking here? And do you simply cut off the nipple and drill the lid for a larger fitting?

 

[Buchanan Automotive]

Hi Timm , to answer you're first question about machining Porsche crankshafts , the numbers DO not stack up in the way too high risk factor , now first of all the Porsche crankshafts are generally & depending on era of when made in Germany were  Tenifer treated from new ( this effects the outer layer of the journals ) so any form of machining deletes this type hardening process , Tenifer = Nitrocarburising  & is a trade mark of Durferrit Gmbh

Note } over the decades the Tenfier treatment has changed to keep in touch with strict environmental regulations , I think in the old days it was in a Cyanide bath at 570 deg cel for a given time with the crank blanking plugs removed ( sounds nice )

Question } Now in regards to the above , if I was asked a simple question }   In the last 39+ years have I ( thats me ) seen / come across / know of people here in Australia that have gone to the trouble of having a Porsche crankshaft ground / machined ( lets say just the conrod journals )  on either a 944 , 944S2 , 951 , 968 , 911 , 930 , 964 , 993, 928 that after 5 years the crankshaft in the engine is still working trouble free & no issues what so ever or did I hear back news that the engine suffered a " Out Of The Blue " failure of a conrod bearing or low oil pressure issues 2 or 3 years in OR after just a few Club Sprint Track days over say a year the crank has FAILED completely & the resulting mess/ destruction is so bad it is mainly guess works of what failed first or why ( chicken or the egg thing )?

Answer =   OVERWHELMING     YES

Why   ?

Answer =   Have no idea & couldn't care one bit , maybe the rehardening process was compromised or who knows or even stupidity in using a too low engine oil viscosity at Max RPM with high core temp( normal temp , but wrong oil viscosity ) , but blaming the failure on the crank repair , we will never really know , but I want NO part of that shit

But could there be a crankshaft repair business in Australia that could successfully machine a Porsche crank & do some form of hardening process & all will be well & no issues in the future ( providing you use the correct oil viscosity ) ?

Answer = There would have to be , but who / where , how can I be sure & I mean 100% SURE & I Mean 100% , what happens to my reputation if it doesn't work ( Internet News Travels real fast with failures), so we now go back to the large numbers of crank failures ( that I have head of over 39 years ) & what incentive is there for me to experiment with someone else's engine that we may be rebuilding to make it a reliable Club Track Car ( say a 951 )when even now good quality 2nd hand 2.5L & 3.0L are available , may be when the day comes and there are NO 2nd hand cranks available 2nd hand anywhere on this planet , then & only then we will have to do something else , but that day has not come yet

Question }  Now what is the RESULT of this failure by the customer who has gone to a lot & I lot of expense to get this engine up & running in regards to the poor buggers who assembled this engine ( SAY ) 6 months earlier  ?????????

Answer  = The Shit Hits the FAN & the shit is flung far and wide its gets one ever thing & every one & now with the internet the shit can be flung all around the world 

I have seen so many fail, it very much worries me ( enter the advantage of 39 years experience ), but the same engine with either a New Porsche crank or a very good 2nd hand one that passes inspection  , we have NO ISSUES at all / None / ZIP / Nothing 

But remember , why was the crank damaged ever so slightly in the first place ???
Answer =  Because some human thought it would be so much better to run the last century  951 (example only ) on a " This Century " so called synthetic low viscosity low oil film strength engine oil , like a 5w-40 or a 10w-40 ( street conditions ) in the Australian weather = warm to hot  , so when the oil temp gets up to normal ( like 95 deg cel ) and the poor bugger goes for Max power , no 2 conrod bearing starves of oil for a second or less , no noticeable damage done by the driver but the bearing shells were scuffed & journal to bearing shell contact was made = slight score wear to No 2 journal , this didn't blow apart , but its slightly damaged 

If it was on a 20w-50 engine oil , it would not happen , so crank damage is human stupidity , nothing more & nothing less 

Has anyone wondered or asked why nearly all( if not all ) the last century Porsche engine failures( including worn out camshafts & metal particles everywhere ) have been when these poor engines were on a diet of a "This Century " low viscosity So Called Synthetic engine oil's , has anyone ANYWHERE seen the Elephant in the room  & the question I have , The So Called Synthetic component of the engine oil ( usually Hydrocracked crude oil in the first place ) has NOT helped one iota, nothing , zero . So much for so called synthetic engine oils in this century ( meaning low oil viscosities )seem to do the reverse , I do find it very amusing & it ( wrong oil choice ) gives us plenty of work 

Now back to numbers for a moment , just for convenience I looked up a set of Standard Size big end ( con rod ) bearings from Lindsey Racing USA ( Example only ) , now the standard size Glyco that we use is sold as a complete set of 8 half shells for $ 74.95 USD  ( complete set )
Now a set of Oversize big end ( con rod ) is sold ( Porsche Genuine Only ) .25mm oversize at $ 85.90 USD per pair   X 4 pairs needed = $ 343.80 USD = $ 465 Aus + Bank fees + air freight  

Then you have to pay to get the crank machined & Hardened after machining & this will probably be ( here in Aus ) Nitriding & you take the risk of it being OK 

For about the same price I would probably buy in a good 2nd hand crank ( in fact I would be happy to pay twice or three times  as much ) so I can sleep at night 

Now all the cranks we discard & blast them in two with the Oxy Acetylene torch to make sure NO ONE can ever ever ever ring me in the future and say , I got off you guy's a 2nd hand crank & I am ringing to complain , even though you gave it too me for free , I feel that I want to complain because I had it repaired & it failed 6 months later & it destroyed the engine & I think you should give me some money 

This is Exactly what happened to a friend & colleague of mine who gave away a 2.7 911 crankshaft about ten/ twelve years ago & the person who got it for nothing had it ground / machined etc etc etc & after a year or so the crank completely failed & tore the engine to bits , well the guy who owned the 911 ( with the free crank ) threatened the colleague of mine with legal action & consumer affairs & he got it for NOTHING

So if any one rings me about a crank that I discarded , then I know the crank was in TWO destroyed parts & can never be reused & boy do I destroy them

As with the AOS , depending on the type , but the bare minimum is opening up the inside dia of the standard plastic fitting ( cast with the top cap ) to the max size you can , but remember we need a lot more , hence why we always vent the top of the cam box as well , so we have two seperate inlets to the catch can 

Regards

Bruce Buchanan
Buchanan Automotive

[Timm]

Hi Bruce, your reply makes a lot of sense, thanks for sharing more of your wisdom. I still have more questions though! (Sorry if I am getting annoying, there is just so much that I want to learn, and I want to do everything right the first time with my engine build)

So, my first question is, should I still get the crank journals polished? Or does even that remove to much material? Should I just measure the crank to see if it's in spec, and if so, just clean and install it with new bearings?

I haven't been able to take any measurements yet as I do not have a micrometer. The rod journals look ok, but there are some worrying longitudinal scratches on two of the mains bearings. Below are some pictures of the crank. I couldn't upload to here so they are hosted externally. There is also a picture of the rod bearings. As you can see, number 1 had a foreign particle embedded in it, and number 3 also shows some uneven wear. So I probably dodged a bullet by tearing down the engine and rebuilding it now.

Crank: http://i.imgur.com/Qrp7EV3.jpg

4th Mains journal: http://i.imgur.com/45jTC5a.jpg

5th Mains journal: http://i.imgur.com/FEGdt4A.jpg

Rod Bearings: http://i.imgur.com/TNcMpfN.jpg

Sorry about the quality, the pics were just taken with my phone.

 

 

 

[Buchanan Automotive]

Yes of course you can have them polished ( main & con- rod crank journals ) , but its the every important" final" measurement of the con-rod journals is critical for a ( track / Supersprint ) Porsche engine , as I mentioned earlier, the measurement criteria we use is not " as" essential for "street Only " application 

A good micrometer is essential for measuring the con-rod journals & main journals of the crank ( before & after the journals are polished )

On assembly ( like most engine repairers ) we use Plastigage ( reregistered Trademark ) , very handy thing to use in the dummy assembly of the engine to check internal clearances between the con rod journals & their respective new con-rod bearings ( refer to Plastigage web site on how to use Plastigage ) as I do not have the time here

So lets just pretend for a moment the crank has been polished & yes to polish there naturally has to a tiny amount of metal removed from the top surface of the journals & lets say the specs for the con-rod journals are say 51.971mm to 51.990mm ( example only ) from a mythical spec book & lets say three ( 3 ) of the journals have a final measurement of say  51.985mm , 51.984mm  &   51.982 mm dia but there is one journal that measures 51.971 mm , this last journal is right on min dia ( within spec ) , now for a street engine it will be fine , providing it ALWAYS has a decent quality 20w-50 engine oil AT ALL TIMES for street use 

WARNING } You have to look up the specs in the workshop manual for crank journal dia's & clearance , the above figures are from my Memory ONLY & are for example ONLY

Now for Supersprint use ,this is not ideal , because with engine oil temp after a few laps of around 125 deg cel & at HIGH RPM under max load that one journal will have the least amount of oil pressure as compared to the other three because the hot ( now thin ) oil has more of a gap to escape out of the bearing sides & its this journal/ bearings that is under risk at high RPM in these conditions ( all simple physics )

Now back to assembly for a moment , in the dummy assembly of the conrod journals & the new con-rods & the new con-rod bearing shells we use Plastigage to double check the findings we had with the measurement ( via the micrometer ) of the crank ( con-rod ) journals and you will then see the extra clearance & then one has to decide what to do 

But if all 4 crank con-rod journals are fairly even & mid range within the spec ( say ) 51.981 mm ( example only ) then thats fine 

Same goes for the crankshaft main journals , but luckily these are normally subject to less loads and less overall normal micro wear , however saying that I am somewhat intrigued by those 90 deg to normal rotation marks on the main journals in the photo's , looks like some sort of tool or VICE was used to hold the crank via a main journal , but surely this would not happen in most normal circumstances ( very odd )

Remember to consult the workshop manual in the preparation & application of the Wurth "Orange" sealant onto the engine girdle to engine crankcase surfaces , this is important because it will effect the crush onto the main bearings by a tiny amount & hence main bearing clearance & this sealant needs to be in place for a dummy assemble with Plastigage to double check the main bearing clearance ( final check ) & naturally reapply the sealant for the final assembly 

Regards

Bruce Buchanan

Buchanan Automotive

[Timm]

Cheers Bruce, your memory is spot on because those are the exact tolerances quoted in the workshop manual for the crankshaft journals. After I have the head back and am happy with the machine shop's work, I will be taking my crank and block in for some more work. I will get them to carefully measure and polish and then measure again the crank. Hopefully the journals will end up nice and even and well within spec. I think I will also invest in a nice micrometer myself so I can double check the measurements. I'm guessing it will come in handy often enough in the future anyway. I am familiar with Plastigauge, my brother should have some left over from his engine build and I will definitely be using it to check over all bearing clearances during the dummy assembly.

The perpendicular scratches on the mains journals have me confused as well...I am not sure how they got there, but they should hopefully polish out easily as they seem to not be quite as deep as the rotational wear marks.

You mention Wurth "Orange" sealant, is there a specific reason you use this? Is it superior to the loctite 574 called for in the workshop manual? And on the subject of that sealant,  one 50mL tube should be sufficient for the build, right? If not, I'd rather order another tube now, than have to wait on it when I'm in the middle of assembly.

[Buchanan Automotive]

Thats a clear signal from a 1970's / 1980's Porsche technician that was working at a Porsche dealership in the 1970's / 1980's , because in that era , we used the" Anaerobic"engine & transmission sealants ( different colours for different viscosities/ thickness) that came Via Porsche genuine , because the engine sealants & trans sealants ( anaerobic ) had their respective Porsche part numbers and very very easily ordered via the spare part dept at our Porsche dealership & naturally this came via Porsche Cars Aust which came via Porsche Germany & Porsche Germany ( in those days & mostly sea freight then ) purchased a lot of consumables through another German company called Wurth ( fancy that ) & Wurth was famous then for this ( Hard to get any other way decades ago ) anaerobic sealants 

So when you hear someone  , use the words Wurth Orange or Wurth Green , that is mentioned almost in semi code or short hand to someone with the same knowledge or has heard of it already , because they had been in the Porsche repair world for decades instead of weeks

The Wurth Orange is most likely just repackaged Loctite 574 

From the late 1980's / early 1990's Wurth started importing consumables to Australia & we at our workshop & most other Porsche independent repairers tend to prefer the Wurth sealant because it was sold by Porsche back decades ago , as for the Loctite 574 in the Loctite branded tube or container , the one thing you are not aware of was back in the late 1970's and into the 1980's this stuff from Loctite was near impossible to buy here in Australia and remember this was not just pre internet this was even deep pre mobile phone , this was the era of Faxes and ( by todays standards ) very very very very very very very bad communications & buying from overseas was a real task 

So you can see why we call Loctite 574   = Wurth Orange & I still buy it today 

The funny things that happened in another century , I am starting to feel old 

Regards

Bruce Buchanan
Buchanan Automotive

[Timm]

Ah, I see. I just ordered the Loctite from the US along with all the other gear for the rebuild, as I couldn't find any for sale in Australia. Good to know the Wurth Orange is interchangeable, because I can order that online from Wurth Australia if need be, and then I won't have to wait on shipping from the US.

This is great, I am learning something new every day! I can't wait for my parts to arrive so I can put the engine back together. Hopefully everything goes well...

In any case, it's really great that you are active in the online community, and we are able to come to you with questions and soak up some of your wisdom. It's almost as good as having my very own mentor right here ;-)

Cheers,

Timm

[Buchanan Automotive]

How funny is that , the Loctite 574 is still unavailable here in Australia , thats hilarious 

Regards

Bruce Buchanan

[Hughesy]

bruce, ive got to tip my hat to you.. youre a true champion.. so very generous with your time and knowledge

regards hughesy