1800vw

VWHelp.com Align Bore Case

*Common
       Motor
      Building
     Mistakes*

09/14/05*

When  the crank end play becomes excessive, the case will most likely need to be "Align-Bored".
It might be after 100,000 miles or more, but it can happen a lot sooner if the motor has been overheated and over revved.
If you don't take care of excessive end play when it first becomes apparent, you take the chance of ruining the case if you continue to use a motor. If you run the VW motor with .015 end play, the end play will double and triple in just a short time. End play develops when the flywheel end, main bearing becomes loose in the case. When new this bearing has approximately .003" crush fit. When the thickness of the bearing saddle measures .790" it will be questionable if the case can be saved. After machining the minimum dimension of a "#2 Thrust" Bearing is .786". Main bearings come in "Std. Thrust", "#1 Thrust" and "#2 Thrust".   Click here for more Bearing information.

There are some builders who refuse to align-bore the VW case. There are several different reasons. We personally have align-bored hundreds of cases and have had no problems. But you must carefully inspect the case to confirm it is worth using. If the lifter bores are worn, case warped or cracked then don't waste your time having it bored.
If you take your case in to have it alien-bored then that's what the shop will do. It's your responsibility to check it out first.
If the Shop builds the motor, then it's up to them to check out the case. Many builders don't want to take a chance or spend the time checking out used cases. It's cheaper for them to just use a new case and pass on the expense to the customer. We personally build all our race motors with used cases as we feel they are more stable after going through the hundreds of heat cycles.

                        *** Check for cracks prior to align boring.***

First place to check is the top right side cylinder stud area on the flywheel end. The crack will go up from the stud and over top of case.

Second place is under flywheel in front of #3 cylinder opening. First clean all oil from the surface behind the flywheel. Then heat up the this cleaned area with a propane torch and look for an oily crack line.

(This is where the 1835cc engines crack if not step bored or if the case saver for the top stud next to flywheel behind #3 cyl. was not deep sunk in the main bearing saddle casting.)

Check if case is warped, any gap between main bearing saddles after the two bare case halves have been torqued, can be seen if you shine a light in one end and look through the other end main bearing hole.

Check the (5) main bearing locating pin holes. Some cases will have six but five is all you will use. If you find a bearing pin loose in the case, this means the case was most likely overheated some time in the past. The case should be checked out a little more closely, but the case can be used with a step bearing dowel or by using a little JB weld to locate the dowel. If the case is align bored with the proper bearing crush ( minus .003" ) then the bearing dowel will do very little until the motor overheats due to a dropped fan belt or some other overheating problem. But if the align bore job was sloppy then the bearing dowel is the only thing keeping the mains from turning.

Place both full circle bearings on there locating pins and mark both sides of bearing at the case parting line. (This will insure the bearings will be installed properly when crank is installed in case)

Check Oil Pick Up (must be tight with no leakage)

"Cleaning the VW Case" and Keeping it Clean

Note: Your case must be thoroughly cleaned after it has been Align Bored but also remember to clean the case before taking it to the shop to be checked for an align-bore. Inspect for cracks can only be done if the case is clean. Remove all bearing dowels, bearings, O-rings from the (6) center case studs and distributor shims.

Pull the oil relief springs and pistons (2 in dual relief late model cases.) and make sure they are installed in the correct hole when replaced.

D-burr all main bearing saddles and flush all oil passages. This can be done at the car wash by plugging all oil passages but two.

Flush the passage in both directions and then move on to the next passage.

We Start with the Oil cooler inlet and outlet and plug and flush all the oil passages one by one.

Some oil galleys will have dead ends where the factory plugs the end of an oil passage.

Over time these dead end passages fill with crud & metal chips that can do major damage to new bearings in just minutes.

If you have any doubt about how clean the passages are, it is best to drill out the plugs. You will have to drill & tap each hole and install a plug after cleaning each passage. Oil Galley Plug Kit includes 5 of the1/8" plugs , 2 of the 1/4" , and 2 of the 3/8" plugs. Scat # 50033
Note: Buy the new oil galley plugs before drilling out the old ones.

Run a thread die down all studs to clean threads and then double check the case parting surface for old gasket sealer and nicks.

Blow out all oil passages with compressed air. After cleaning, store the case in a plastic trash bag to insure it stays clean. main bearing

Note: Cam bearing bore = 1.082 / 1.085" ( Bore gets smaller with wear. ) Most Shops will check the cam bore and true when they Line Bore the case. "Be Sure to Ask"
Oversize cam bearings #111 198 542 order $17.95

"Take your time" -- "Keep it Clean" -- and -- "Read the Book"

........Never use Silicon seal as a gasket sealer,........

Check for air leaks, and Check for air leaks again.

Always set the timing by the book, You can not set the timing at an Idle by ear.

Your Engine will overheat and be destroyed if timing is off or if carb jetting is to lean.

..... Clean Air *..... Clean Oil *..... and .....Do Not let it Overheat.....

Align Bore Q&A->*Click

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Victor Comp. Products Inc. **--Vic's--**Phone 816-650-3535 • 230 S Hudson St., Buckner, Missouri, 64016, US
All Questions should be E-Mailed to Vic's

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