Straight gear interaction ?

[NachoCar]

Long, long story but I was told by seller of project type 1 that the shortblock was assembled by seasoned VW tech. Knew it was a gamble but decided to finish and deal with engine once I got to that point. Eight or so years later, I put stock rebuilt carb, dist, etc. Engine ate a cam gear first time it got any load on it.

Been working on rebuild for bout 6 months, first build. Got case back from Nick couple weeks ago cut 2 over. Been thru a couple sets of main bearings learning how to get the crank located and set.

Aftermarket cam gear was too tight. Decide to go with straight cut gears as a way to avoid trying to spend time and money finding looser OEM cam gears, that may or may not be correct. Read no worries with gear lash.

Well....SOMETHING is killing me. During mock-ups with crank torqued, everything is fine.

Mock-up with cam did get tight so went with diff cam bearings. Still binding a bit when torqued. Bearing scraper on order but tried sanding cam bearing thrusts on paper (I know, a big no-no). But worked and got a nicely spinning cam even when in properly torqued case with all the nuts/bolts even peripheral 13 mm's.

But damn it to hell, when I put crank, cam, lifters, dist drive in together starts to bind when I torque the two 13 mm at what I call the nose. You know the ones on either side of the #4 bearing (unsure if that is correct number and too pissed to verify). I mean I tried every combination of sequence and torque in little baby steps of torque.

Knowing my main bearing experience, I thought for sure the last time (Prob 5/6th time) I KNEW everything was perfect so I could button her up. Nope....

This is after opening up the last time. Ya'll see anything incorrect? I didn't

I'm wondering if I missed info on the straight cam gears interacting once the case is torqued down?

I also read cam endplay is not AS important on straight cut cam gears!?!

There are quite a few possibilities/variables as far things like Main bearing ID's being off, but I did test that variable when I torqued crankshaft in case (with ALL hardware) by itself. Just like when I torqued down cam shaft by itself with all hardware (Nuts and bolts)

All I can think of is there must be gear lash, or something else to check.

I pulled crank out but main bearings looked fine and rotated alright?

Any next steps or missing adjustments????

A little knowledge is an expensive and time consuming thing......

[NachoCar]

I did wipe down edges with Acetone before the above pictures.

Noticed these a bit later:

Could be acetone washing down Permatex aviation I used to seal case half surfaces post case splitting last time or, I guess it could be from while I was trying different torque sequences.......but would maybe bind when torqued??

I'm really reaching here guys.....

Thanks for any help given.

I need it, obviously.

[chrisflstf]

That dowel pin looks bad. It may be sticking up too high, pinching the bearing and why is it distorted on one side?

[NachoCar]

Good Eye! or maybe you have 2.

Stock size dowel pin, 8mm was warned to me to be too short by aviation mechanic. I guess it had been pushed in too much in some previous life?!?

Ordered 10 mm pins and ground down. I did measure upon assembly by marking with sharpie then fitting into bearing hole.

The crank turned beautifully when test fit in case without cam shaft and all hardware....even 13 mm nuts torqued to spec.

Thanks!

[txoval]

Way to much sealer, it’s all over your bearings…

[NachoCar]

agreed. I wondered if that happened after I spit the case and wiped some off or not.

either way it's too much.

Thanks

[NJ John]

Are the lifters binding when the cam is at full lift?
_________________
1973 standard, yellow, lowered, 3” narrowed front, 1600 blo-thru turbo w/single dell 15.4@86, so far
11.41 et buggy. Long gone
Let’s go O’s! Let’s go O’s!
https://www.youtube.com/@AirSpooledGarage

[raydog]

Why do you have the distributer, distributer gear, oil cooler, etc. all installed already while you are trying to figure out and assembly problem? Get rid of the unnecessary items, including the oil pump, and especially the drive gear, put them on after you figure out the binding problem. Have you been turning engine over with dist. drive in place with no distributor? Stop shooting the cannon at this thing, be methodical, and listen to your advise. I am just trying to get you to step back and take a breath, one step at a time.
_________________
Come on, It's not rocket science. KISS

[NachoCar]

Oil pump is out. Under the impression it wouldn't hurt to leave dist drive and dist in place once verified to mesh with crank.

I have read not to rotate the crank backwards with drive in place and dis bolted down as the gear would poss mess up brass gear on crank ?!? I'm not really rotating backwards now that I don't need to check the stock type cam gear is too tight by rotating crank backwards.

Rem I have made dang sure the crank does not bind in case when torqued fully all fasteners. Seemed smart to try it with dist drive in place.

That is true as well for cam, when not in case with crank.

I appreciate the help guys as I know there is a whole lifetime of experience some of you have. I also know I don't know shit. Guess I'll have to watch the lifters closer.

[NachoCar]

so straight gears are pretty much set cam endplay and go?

as long as backlash does not occur?

[bsairhead]

With the distributor in place it's fine to turn the crank backwards. That's how you check valves by the book. Without the distributor set the drive will walk out if the crank is turned CCW

[Pruneman99]

You can leave the crank, cam and everything in the one case half. Grab the two rods sticking up and cycle the engine. If the cam gears are too tight, the cam will want to walk out of the bearings.

[Glenn]

Is that a stock crank, 311b rods and straight gears.?
_________________
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"

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עַם יִשְׂרָאֵל חַי

[Starbucket]

You need to get a tube of Prussian blue and paint the crank gear with it and see what contact pattern you get on the cam gear and maybe lay a couple of strips of plasti gage afterwards to see if there is any clearance. Was the case ever align bored the mains may be off a little.

[NachoCar]

[Pruneman99]

Unfortunately new bearings are pretty sloppy now. You'll need to torque the case without the bearing and measure the bore for #4.

Then measure the OD of the bearing to determine crush.

If that's OK, then put the bearing in the case, torque everything again, and measure the ID of the bearing.

Compare that to the crank journal.

From your description, I think you may find an issue with one or more of these measurements with your #4.

[NJ John]

And you know the deal with the front nearest the pulley. The one in your last pic. Amateurs have a hell of a time getting that one seat.
_________________
1973 standard, yellow, lowered, 3” narrowed front, 1600 blo-thru turbo w/single dell 15.4@86, so far
11.41 et buggy. Long gone
Let’s go O’s! Let’s go O’s!
https://www.youtube.com/@AirSpooledGarage

[NachoCar]

[NachoCar]

[Pruneman99]

I haven't had the problem with too much bore crush. That's not to say that's not what might be happening here though. If there is too much crush, that little bearing could be crushing on the ID, and grabbing the crank.