New case or rebuild

[bwburd]

I recently bought a 77 sunroof with a locked up motor. I got it home and found the case full of water. The cylinders and the crank are pitted so those need replacing. The case is magnesium but there arent any markings on it. The previous owner didn’t know much about it.

I’m not sure if I should start fresh with an aluminum case and new parts as needed. I’m thinking around 1900-2000 cc street motor.

What route would you guys take. I’ve been looking at parts trying to figure out what compliments each other.

[Glenn]

Water in a magnesium case is no bueno.

I'd start with a new case.
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Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"

Member #1009

#BlueSquare

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[bwburd]

That’s what is was thinking. Then I would know the history of it starting fresh. The only spot that I can definitely see damage is around the oil screen sealing area.

[67rustavenger]

[txoval]

You don’t have to buy a bubble top case…but fitting the tins just takes a bit of trial and error. It’s not difficult

I would go with a new case

[mikedjames]

If the case is holding water, it will probably hold oil.

But the other problem is the corrosion flakes that need to be cleaned.

I had an AS21 case, had half an inch of water in it, but most of the corrosion was the camshaft gear (half vanished) and outside of the case. It cost £51 on eBay plus a trip of about 150 miles to collect( it was 99 miles direct from my house, I asked eBay to search up to 100 miles)

I used a parts washer to flush the oil galleries until bits of corrosion stopped coming out .

I used JB Weld to rebuild metal in places where e.g. M8 case sealing studs went through half eaten lugs so there was nothing for the nuts to tighten down on.


Crank, flywheel and conrods were good, and smashing the cylinders off was fun.


Ran it for 27000 miles until it dropped a valve. Never had very good oil pressure, because I used 0/0 bearings


If you can afford it go for a more durable new aluminium case.
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Ancient vehicles and vessels

1974 VW T2 : Devon Eurovette camper with 1641 DP T1 engine, Progressive carb, full flow oil cooler, EDIS crank timed ignition.
Engine 1: 40k miles (rocker shaft clip fell off), Engine 2: 30k miles (rebuild, dropped valve). Engine 3: a JK Preservation Parts "new" engine, aluminium case: 26k miles: new top end.
Gearbox rebuild 2021 by Bears.

1979 Westerly GK24 24 foot racer/cruiser yacht Forethought of Gosport.
1973 wooden Pacer sailing dinghy

[Glenn]

[bwburd]

Thanks for all the replies. I keep going back and forth on what to do. It would save a good bit of money to stick with the mag case. I have to get a crankshaft either way

[Glenn]

Post some pictures.

BTW, you never build a house on a bad foundation.... food for thought.
_________________
Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"

Member #1009

#BlueSquare

עַם יִשְׂרָאֵל חַי

[bwburd]

I’ve only cleaned the one half really good. The other half looks like it’ll be similar with the exception of the corrosion at the oil pan

[RickS]

[Glenn]

I sit corrected.

I guess you can more easily weld an aluminum case.

I've built 200hp engines with both and see no advantage so far.... except the mag case is significantly lighter.
_________________
Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"

Member #1009

#BlueSquare

עַם יִשְׂרָאֵל חַי

[heimlich]

Magnesium is lighter and runs cooler.

Looks like you have a little corrosion next to the drain plate which can be dealt with easily. Do you see corrosion anywhere else?
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[bwburd]

no. everything else cleaned up pretty good. should i just go with a stock rebuild and stock crank on this case? and maybe build a aluminum case higher cc engine for later. this is my first vw build but not first engine build. ive done small block chevys and a big block ford before

[esde]

Check the saddles for spread, check all the studs, inspect behind #3, and generally give it the most scrutiny you can. And then send it for line bore and ask whoever does the work to check also. You already own this, and if it is good there's no reason to not use it.
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modok wrote:
Bent cranks are silent but gather no moss. I mean, ah, something like that.

[txoval]

Looks like your lifter bores are pitted

I’d scrap it, but that’s how I am. That case needs an align bore, case savers installed, lifter bores sleeved, clearanced for stroker crank, cylinder bores opened up, and the deck machined.

Even if you went stock, you still need an align bore, lifter sleeves, case savers, and the deck cleaned up. Go price that work

[jpaull]

Good catch Txoval. Yes, those lifter bores are toast.

Get a aluminum case. Once you "polish a turd" and pay to have all the work done to it to fix that mag case, then it will still have a issue later. Build a engine on a good foundation so you can do a nice job and not have to pull it out later and spend the cash twice. Its a lot more expensive that way, and more hours of your labor.

The mag cases flex more then aluminum. The wind blows the wrong way and they have issues. Nothing like the solid cast iron blocks your used to. The aluminum is one step closer though.
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[email protected] MPH 1/4 Mile & 8.1 @ 83.7MPH in 1/8 Mile with Mild Type 1 VW Mag Case 2234cc commuter engine in stock weight bug w/only .491 total lift(CB2292 Cam), 42x37 heads, 48idf's, Street tires, Belt on, Mufflers, Pump gas, video of the run here: https://youtu.be/M3SPqMOKAOg

Transmission by MCMScott:
Rhino case, Klinkenberg 4.12, Superdiff, 002 mainshaft with 091 first idler. Weddle 1.48 Third & 1.14 Fourth.

[bwburd]

okay cool. what are some good websites to buy a case from.

this is the one ive been looking at, 90.5/92 case from jbugs
https://www.jbugs.com/product/98-0453-B.html
also, what what be a good cc size for street performance/ drive to work every once in a while. i was thinking 1904 to 2007 cc

[jpaull]

The CB version has a little more piece of mind then the others. And its the same or less price then that jbugs you linked to.

https://www.cbperformance.com/product-p/1160.htm
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[email protected] MPH 1/4 Mile & 8.1 @ 83.7MPH in 1/8 Mile with Mild Type 1 VW Mag Case 2234cc commuter engine in stock weight bug w/only .491 total lift(CB2292 Cam), 42x37 heads, 48idf's, Street tires, Belt on, Mufflers, Pump gas, video of the run here: https://youtu.be/M3SPqMOKAOg

Transmission by MCMScott:
Rhino case, Klinkenberg 4.12, Superdiff, 002 mainshaft with 091 first idler. Weddle 1.48 Third & 1.14 Fourth.

[bwburd]

thanks.
how do i determine which deck height to choose