engine block dowel pin

[MTT3107]

So, this weekend, we pulled the engine on my '73 beetle project.
According to the number on the block, it's a 1300.
Once we start taking it apart, turns out a previous owner had already put 1600 pistons and barrels on it. So far so good..
But we noticed rightaway that the crankshaft axial play was way too much.
Anyway, finished taking it a part, and turns out that whoever assembled the engine, messed up with the dowel pins which locate the rearmost main bearing, and the block is damaged there.
Is that something a machine shop can fix, or is this block toast ?

Could the area be filled in, remachined, and a new dowel pin hole be drilled ?

[61SNRF]

No big deal but that is the FRONT main bearing saddle in your picture. Looks pretty bad. That bearing also takes the thrust load so whatever you choose to do it must be tight and solid. That bearing must fit in the case so it does not move back and forth. You want your machine shop to measure and make sure the case is not pounded out in that area too. Long term you might want to consider a new case.

If your machine shop is willing I have seen custom made stepped dowels in engines. That is where it's base is say 1/4" with opposite the end turned down to whatever spec a new dowel is. With these you would bore the hole in the case to 1/4" and use the dowel like normal. Thing is it doesn't look like your case would support a 1/4" hole where the old dowel wobbled it out.
You might try filling the hole with JB weld then using a drill press go for the 1/4" hole and stepped dowel. In theory once clamped tight it shouldn't move but with continuous heat and load cycles it may ultimately loosen and develop play.
_________________
-Bruce

An ounce of prevention is worth a pound of cure.

[volksworld]

ok the dowel pin isnt the problem...it is the result of the problem...the rear main bearing saddle has been beaten to death and run for a long time with a very loose bearing...now cases can be line bored for oversize bearings IF the damage isnt too severe...but the case may have already been bored and thrust cut once or twice already and could be too far gone to save...the case should be torqued together and checked to see if theres any gap between the split center bearings saddles...if so its a goner even if it cleans up with a line bore...just looking at it i'd throw it out but i'm sure worse ones have been saved ....the pin hole could be welded, epoxied or oversized...its just a matter of how sleazy a repair you want to do to save the price of a new case....just be aware that the end result wont last as long as a new one

[MTT3107]

Ok, thanks for the answers !
Thing is, I already managed to get my hands on another block, actually a whole engine, a 1600 fuel injected.
I just thought I might be able to save this block and maybe sell it.
The one we ( my brother and I) found, we found it on facebook marketplace, it engine looked really crappy, had been sitting outside somewhere for quite a while, but it was listed for $200, and we figured, for that price we might take the risk and maybe at least get the block out of it..
Took it apart, piston cylinders and cylinder heads look good, must need lot of tlc..
Haven't split the block yet but so far everything looks pretty good..
We'll see...
And at least I got the dual port cylinder heads out of it, the ones from the engine in my beetle are single port.

[67rustavenger]

The dowel pin aligns the bearing to the oil galley.
Once the case is correctly torqued. The dowel pin is no longer in play.
That goes for all of the crank bearings.

The ex-wife blew the o-ring out of an oil filter years ago during a cold startup.
The crank seized within 4 miles.
When I tore the engine apart. One of the dowel pins wallowed out the hole in the case. I didn't fix the pin hole. Just installed new larger bearings after the line bore.

The engine ran thousands of miles before, I gave the car to an ex-brother in law.
_________________
I have learned over the years.
Cheap parts are gonna disappoint you.
Buy Once, Cry Once!

There's never enough time to do it right the first time. But there's always enough time to do it thrice.
GFY's Xevin and VW_Jimbo!

[gt1953]

If it were mine in that situation simpe answer new case, or newer case. You will be glad in the long run. Yes it sucks but do it right.
_________________
Volkswagen: We tune what we drive.
Numbers Matching VW's are getting harder to find. Source out the most Stock vehicle and keep that way. You will be glad you did.

72 type 1
72 Squareback
({59 Euro bug, 62, 63, 67, 68, 69, 73 type ones 68 & 69 type two, 68 Ghia all sold})

[MTT3107]

Yes, I will be going with the "newer" case from the fuel injected engine we bought, basically it was sold for scrap..$175....
Complete engine, although without fan, only the housing.

Anyway, all the tin on that engine is crap, but the block is good as well as the crank and camshaft, and cylinder heads. So I will probably use that block, with the crank and piston and cylinders from my engine, and the dual port heads from the scrap engine.

[calvinater]

One note, the FI engine case requires an electric fuel pump.
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"Albatross"!

[gt1953]

The fuel injected fan schroud has a velocity ring on the fan intake area.
_________________
Volkswagen: We tune what we drive.
Numbers Matching VW's are getting harder to find. Source out the most Stock vehicle and keep that way. You will be glad you did.

72 type 1
72 Squareback
({59 Euro bug, 62, 63, 67, 68, 69, 73 type ones 68 & 69 type two, 68 Ghia all sold})

[RWK]

Also shroud will need a hole for accelerator cable, and hoover bit fitment is different at the cooler.
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73 Type 181
63 Type 113
63 Type 261- 428 071
62 Type 241-378 025 178 530

[MTT3107]

@RWK : Will drill the hole, but what do you mean by "hoover bit" ?
@gt1953 : What is that "velocity ring" ?
Anyways, the shroud will be new, and I will be using fan and alternator from the engine which came with the bug.
@calvinater : Yes, I will be installing an electric pump.

Regarding the block with the damaged dowel pin area in the font main bearing area :
Spoke to a couple of machine shops, and they advised against filling that area in, and drilling a new hole for the dowel pin.
But another shop confirmed what 67rustavenger said : The dowel basically is only needed during assembly, to assure that the hole for oil to the bearing is aligned with the oil gallery. Once the case is torqued down, the dowel pin becomes redundant.
But even so, upon closer inspection , I found that the excessive axial play of the crank had caused it to rub on the no. 2 and 3 bearing saddles..
So I gave up on saving this case.

[gt1953]

fuel injectedfan shroud. Look at the area where the air is drawn. Notice the ring around the air intake area. That is the velocity ring which assist in cooling air as the fuel injected engines rana lil hotter. Look at the photos in this add.

https://www.thesamba.com/vw/classifieds/detail.php?id=2350306
_________________
Volkswagen: We tune what we drive.
Numbers Matching VW's are getting harder to find. Source out the most Stock vehicle and keep that way. You will be glad you did.

72 type 1
72 Squareback
({59 Euro bug, 62, 63, 67, 68, 69, 73 type ones 68 & 69 type two, 68 Ghia all sold})

[MTT3107]

gt1953, thanks for the clarification...

The shroud and tins that came with that engine were crap, totally corroded..
So I will have to get a new one, also the tins.

Cant use the ones from the engine of my bug, since it was single port, and I will be using the heads from the FI engine

[gt1953]

What ever you do if you purchase new tins they are JUNK....stay with the German orginal tin it fits every time. A German refurbished part, tin etc is way better then junk you get today. The classifieds are your freind.
_________________
Volkswagen: We tune what we drive.
Numbers Matching VW's are getting harder to find. Source out the most Stock vehicle and keep that way. You will be glad you did.

72 type 1
72 Squareback
({59 Euro bug, 62, 63, 67, 68, 69, 73 type ones 68 & 69 type two, 68 Ghia all sold})