VW Mid Engine Trike

[vwbug72501]

I'm with Larry on the spark plug. Doesn't look as new as the other 3. Check and see if it has a different p/n on the porcelain insulator. If the same #, inspect the threads closely and you will see the helicoil threads under the gunk. You can probably install a new helicoil with some Loctite and be good.

I'm with Rex on the check the heads for cracks too. Typical cracks are from valve seat to spark plug hole or between valve seats. They can be very obvious or teeny-tiny hairlines so inspect carefully. If they're cracked, scrap the heads. Check out "Need VW type3 DP 1600 heads" thread for pix.

Welcome to the world of old VW engines.

[Rickus Dickus]

Finally got the Gland nut off today. Snapped the drive off of my 3/8" ratchet, but got it. Split the engine case in two and a quick inspection found only one problem. The rear crankshaft bearing looks like it tried to spin. Once the block is cleaned up, I'll be examining it and the heads as best I can. That one "oversize" spark plug did not have a helicoil on it, so it makes me believe the prior owner had a helicoil in it, probably came out, and just stuck this spark plug in it to sell the bike.

[DeathBySnuSnu]

Ouch.

Hopefully the case can line bore.

[Rickus Dickus]

The case has a small raised portion where the pin tried to bend over. Other than that (from what I can see) it looks fine.

I removed the jug bolts and noticed each one has a helicoil in the block. One did come out with the bolt, but other than sitting just above the block, the others look good.

No grooves or damage on the crankshaft and the rod side clearance came up at .012" which is well within the books spec's.

Measured the crankshaft mains at (front of engine to back) 1.573" / 2.165" / 2.165" & 2.166"

The connecting rod journals measured at cyl 1=2.165", cyl 2=2.166", cyl 3=2.165" & cyl 4=2.165"

Since it has been a long day between trying to get rid of this cough, working on my Yamaha trike parts, rebuilding my media blast cabinet, and this VW engine, (a little bit on each one), I'll be bumping these measurements against what my book says about in/out of spec's.

No visually detectable cracks in the heads, but three of the four spark plug holes (including the one oversize diameter plug) have/had helicoils in them. From what I see on the internet about helicoil type thread repair for spark plugs not being an optimal fix, I plan to remove the helicoils and install spark plug repair inserts.

After getting a broken tooth fixed tomorrow (tough spaghetti), I'll get back on cleaning the muck out of the engine block.

[DeathBySnuSnu]

Check that bore for the thrust main carefully.

I have not ever seen one with a bearing damaged that bad that the case was not loose on.

A good used case might be stained on the bearing saddle but you can not feel any step to it. No step feel? Then it is time to torque the case and get out the micrometer.



If you can see or feel a step then it is most definitely bad and needs a line bore.



Case head stud inserts are a good thing.

[vwbug72501]

https://dunebuggywarehouse.com/https...y-engines.html

Looks like stock bore crank. Need to measure the OD of the bearings (the Bore Measurement referenced in the chart) to see if case has been align bored before. If you're lucky enough to have a virgin case you will have a lot of rebuild options available to you.

[Rickus Dickus]

The bearings fit nice and tight except in the center. That one slides in and out of place quite easily. Waiting for my new dial caliper to arrive for proper measurment.

Does anyone have a shop or business to recommend sending my engine case to for line boring? Can't find anyone withing 200 miles of my house. Or, directing me to a line boring set/kit that a DIYer can do it himself?

[vwbug72501]

Try these guys: http://neworleansaircoolers.com/

Local VW clubs are usually great resources.

[Rickus Dickus]

Try these guys: http://neworleansaircoolers.com/

Local VW clubs are usually great resources.

Thank you. Didn't think about clubs. Contacting them right away.