Groves cut into the crankshaft main journals

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Doug Thomson
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Re: Groves cut into the crankshaft main journals

#16 Post by Doug Thomson »

Thanks, What are they normally or originally plugged with?
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Jacques Lefriant
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Re: Groves cut into the crankshaft main journals

#17 Post by Jacques Lefriant »

Not to confuse things the later cranks are what is called cross drilled so plugin the holes is necessary for proper oil pressure to the rods. Now if a crank is ground or in service for quite a while grit builds up in the galleys next to the plugs. So to clean the galley the removal of the plugs facilitate that. A big warning if you are conscientious and have the crank thermally processed for hardness the existing plug may come loose. some shops do not bother to pull the plugs and hopefully they will check to see the plugs are not loose. The best shops will thread the holes and use screw in plugs that are easily serviceable in the future but in reality they might as well use press in ones since the next time the crank is junk or the no one will care.
j
 

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Re: Groves cut into the crankshaft main journals

#18 Post by Doug Thomson »

But what are the non-threaded plugs made from and what is the process for removing and replacing? Is replacing the plugs in the crankcase a similar process?
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Re: Groves cut into the crankshaft main journals

#19 Post by WilliamVaughan »

Hey, now wait a minute!

"Is replacing the plugs in the crankcase a similar process?"

Don't get too enthusiastic about said plugs.

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Re: Groves cut into the crankshaft main journals

#20 Post by Doug Thomson »

Sorry!
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Re: Groves cut into the crankshaft main journals

#21 Post by WilliamVaughan »

The galleries in the aluminum crankcase can usually be cleaned satisfactorily with solvents and dowls and paper towels and rinsed with detergent and water and more water. If you received your engine in working condition, and the crankshaft shows no evidence of having been destroyed by abrasives carried in the lubricating oil, then aggressive cleaning of the crankcase is not likely necessary. Don't drill out plugs in the crankcase unless there is some good reason. Stick a garden hose into the galleries and make some interesting geysers before you even think of removing the plugs swedged into the crankcase.

If however somebody brings a sandblaster within range of the crankcase, then maybe such concern might be warrented. Others know better than me.

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Re: Groves cut into the crankshaft main journals

#22 Post by Mike Horton »

Doug Thomson wrote:But what are the non-threaded plugs made from and what is the process for removing and replacing? Is replacing the plugs in the crankcase a similar process?

An approximate 1/4" Aluminum dowel, semi tapered on the inside end, about 3/8" long, driven in with a blunt ended punch, about the diameter of the hole. The typical replacement is a 1/4" X 28 threaded set screw X 1/4" length (what I used), threaded into the hole in a tough alloy forged steel crankshaft, tapped with a sturdy, new 1/4 X 28 tap, and sealed in place with a high temp Loctite.

PSA: Here I'll borrow a phrase from Jack Staggs, "Don't try This At Home!

This is a tedious process, requiring certain special tools, a fairly high level of skill, knowledge, experience, and patience. Broken carbide tools, are a challenge to remove from a precious high $ crankshaft! What more can I say...


… you asked...
Last edited by Mike Horton on Thu Aug 09, 2018 10:35 am, edited 1 time in total.
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Re: Groves cut into the crankshaft main journals

#23 Post by Mike Horton »

Robert Vaughan wrote:The galleries in the aluminum crankcase can usually be cleaned satisfactorily with solvents and dowls and paper towels and rinsed with detergent and water and more water. If you received your engine in working condition, and the crankshaft shows no evidence of having been destroyed by abrasives carried in the lubricating oil, then aggressive cleaning of the crankcase is not likely necessary. Don't drill out plugs in the crankcase unless there is some good reason. Stick a garden hose into the galleries and make some interesting geysers before you even think of removing the plugs swedged into the crankcase.

+1

If however somebody brings a sandblaster within range of the crankcase, then maybe such concern might be warrented. Others know better than me.

I did this once, but most wouldn't want to pay the shop labor bill, for the long drawn out cleaning process, which requires some knowledge of chemistry, large volume tanks, a heat source, etc. I'll stop here, "Don't try this at home", as Jack Staggs is prone to say,
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Re: Groves cut into the crankshaft main journals

#24 Post by Al Zim »

Get someone to measure the engine carefully! Have the crank and rods magnafluxed. Use a tri-micrometer to measure the bore of the engine case. Measure the valve stems top and bottom to determine the taper in them. Use a go-no go gauge to measure the bore of the valve guides. Check the lifters by putting a drop of engine oil on one lifter and stick it to another lifter. If they stick together they are worn out...and so is the cam. If most of these things exist then you probably have an engine that cannot be rebuilt at a reasonable cost. al zim 2018/08/09
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Re: Groves cut into the crankshaft main journals

#25 Post by Jacques Lefriant »

Hi Doug
I don't think Al realizes that you may be in France that is why i recommenced you get some local advice from Olivier in Paris. Guys like Al who had shops in the last century serviced the customers that the dealer could not or did not want to. they somehow they managed to keep the cars going and made their reputation. In the USA there were a lot of DIYs, VW enthusiasts and Hot Rod engine builders so parts, machine shops, specialty dealers etc so engine building can be done better/cheaper than a dealership or local garage can accomplished. If you get reasonable advice you should be able to get a serviceable engine just tailor it to your expectations.
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Re: Groves cut into the crankshaft main journals

#26 Post by Doug Thomson »

Hi Jacques,
I am an American living in Savoie, France, 7 hours from Paris. You guys living in the States can't imagine how hard it is to find people who know and get machine work done on 356s locally. During the 90s I had worked with a friend, Alan Howes in Connecticut, who spent his life working on porsches. He was such a great source in Ct and since I have been here. Sadly, He passed last year. I have heard of Oliver but it would be difficult to get my parts up there and then go back to pick them up. I found a place local, 2 hour drive, and I will give them a try. I have admired you all from a far, Thank you.
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Re: Groves cut into the crankshaft main journals

#27 Post by Juha Vane »

Hi Doug,

Check this in Germany:
https://www.ahnendorp.com
They alignbored my case and seem to know what the do.
KTF,

Juha Vane
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Re: Groves cut into the crankshaft main journals

#28 Post by Doug Thomson »

Thank you Juha, I corresponded with them and found them very helpful but they are even farther than Paris and they have a 4 to 6 month waiting list. I have also use Albert Häfner of Classic-Parts-France who has been very helpful and does nice work but also 6 hours away. I was looking for something in the Lyon or Grenoble area. I found a nice family owned shop just 2 hours away, Euroculasse. I just dropped my parts and they spent an hour showing me around. I feel comfortable with them. We will see how it works out. Fingers crossed. As Al pointed out there are so many pieces which have to be checked, shipping would have been prohibitive.
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Re: Groves cut into the crankshaft main journals

#29 Post by Jacques Lefriant »

Hi Doug
I am very impressed with Ahnendorp since they can address the oil pump by machining the 3rd piece and fitting oversize gears. to my knowledge they are the only ones that do this much needed service. I have worked with Olivier and he is a true master of engine building and very knowledgeable in 356s it may be worth the trip to Paris to pick his brain.
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Re: Groves cut into the crankshaft main journals

#30 Post by Olivier Auvray »

Jacques Lefriant wrote:Hi Doug
I am very impressed with Ahnendorp since they can address the oil pump by machining the 3rd piece and fitting oversize gears. to my knowledge they are the only ones that do this much needed service. I have worked with Olivier and he is a true master of engine building and very knowledgeable in 356s it may be worth the trip to Paris to pick his brain.
j
I'm not a true master, you are a true master! You was the cover boy of Auto Motor und Sport............... not me!
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