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Sun Mar 25, 2012 5:39 pm

I'm shopping for the rest of the parts to put my '62 engine together, but I have a few questions. It has been years since I've messed with "late model" engines, but I've done a few 25hp and 36hp engines in the past few years.

* Can I use normal 1600cc P&C's? ie the AA kits that are available?
* Is it possible to use 1641 P&C's? I only ask because I have a set I got cheap at a swap
* is the seal kit the same as a normal 1600, or is there a Type 3 kit? The only seal I can think of off the top of my head that's different is the oil filler.
* I see there are 40hp and 1600 pushrod tubes available - which are correct?
* I need a set of 8mm head studs; are there recommended kits or ones to avoid? I had ARP studs on my 911, but I don't know if it's worth it to spend $400 on head studs for this engine.

Sun Mar 25, 2012 6:58 pm

thom wrote: I'm shopping for the rest of the parts to put my '62 engine together, but I have a few questions. It has been years since I've messed with "late model" engines, but I've done a few 25hp and 36hp engines in the past few years.

* Can I use normal 1600cc P&C's? ie the AA kits that are available?
***Not without machining the case. 1500 P&Cs are out there. You don't want the "domed" type- those are S Class only. Get excellent used ones, hone the cylinders, and replace the rings. Balance your assembled piston, rings, rod bearings, and rods against each other and file material off at the approved points till they're all within 1/2 gram (or preferably less) of the lightest assembly. I can't stress BALANCING THE WHOLE ASSEMBLIES enough.
*Is it possible to use 1641 P&C's? I only ask because I have a set I got cheap at a swap
***You're right- they're cheap. Thin cylinder walls. They're best suited for use as paperweights and ashtrays.
* is the seal kit the same as a normal 1600, or is there a Type 3 kit? The only seal I can think of off the top of my head that's different is the oil filler.
***And, that seal should be included in the 1600 kit.
* I see there are 40hp and 1600 pushrod tubes available - which are correct?
***1600
* I need a set of 8mm head studs; are there recommended kits or ones to avoid? I had ARP studs on my 911, but I don't know if it's worth it to spend $400 on head studs for this engine.
***Just stick with original. I'm sure one of us on here can get you a set. Maybe you should send the case out for case savers. The 911 needs the beef; on a 1500 it's unnecessary overkill. Use the money where it's needed.

See my thoughts in *** under your queries.

Sun Mar 25, 2012 7:12 pm

I just got the case back from RIMCO, and they installed case savers, but I have to go down to 8mm studs from 10mm. I had the crank, fan, flywheel, and rods balanced as well.

Sun Mar 25, 2012 7:22 pm

thom wrote: I just got the case back from RIMCO, and they installed case savers, but I have to go down to 8mm studs from 10mm. I had the crank, fan, flywheel, and rods balanced as well.

Why did they choke you down to 8mm studs? :?

Sun Mar 25, 2012 7:44 pm

Tram wrote: thom wrote: I just got the case back from RIMCO, and they installed case savers, but I have to go down to 8mm studs from 10mm. I had the crank, fan, flywheel, and rods balanced as well.

Why did they choke you down to 8mm studs? :?

Dunno. I sent the case with the instructions to install case savers, and this is what they gave me. I was surprised as well, but I figured they had a reason. On my 36hp/25hp cases, they drilled and tapped for the larger ones. Maybe they're getting cheap?

I will say this: my experience with RIMCO this time around was not as smooth as it has been in the past. For instance, they sent the case, crank and rods back, but didn't tell me what they'd cut them to. I asked them if they coud pop the oil plugs and really clean the case; they guy said "Sure!" on the phone, but didn't do it. There was a little note on the receipt saying they only clean the case enough to machine it. So what's the $45 to "clean and inspect" the case? I went back and looked at the work order, and it's not real clear on the studs; it says "replace customers inserts same size" - there were no inserts to begin with, and two of the studs had already pulled. I could have gone down to ACE hardware and bought the little inserts myself and saved $130.

Mon Mar 26, 2012 7:50 am

the factory went to 8mm studs for a reason

Mon Mar 26, 2012 7:57 am

Since when do you have to machine the case to go from 1500 to 600? I sure didn't.

1641 type 3 - do-able, but won't last more than a couple seasons

Mon Mar 26, 2012 11:45 am

Slow 1200 wrote: the factory went to 8mm studs for a reason

And that reason is???

(no, seriously, I don't know)

Mon Mar 26, 2012 12:42 pm

thom wrote: Slow 1200 wrote: the factory went to 8mm studs for a reason

And that reason is???

(no, seriously, I don't know)

Cheaper cost, less metal used, less chance of pulling out (although they all got case savers too). They also expand better, matching the cylinder expansion.
IF it really bothers you so much, I'd take the case back to them, and explain that it originally had M-10 head studs, and I wanted (and paid) for them (the M-10 case savers), not having M8's put in, since you had already pulled a M-10 stud out. And that IF they're going to install M-8's, then they need to supply the studs as well, since you've already got the M-10's.

I actually prefer the M-8 studs myself, and IF they had done that to my 71 case, it wouldn't have bothered me a bit. :wink:

Mon Mar 26, 2012 12:59 pm

thom wrote: Slow 1200 wrote: the factory went to 8mm studs for a reason

And that reason is???

(no, seriously, I don't know)

8mm studs will expand at the same rate as the cylinders do. Thus the head torques stay constant and you don't pull studs out of the case.

The 10mm studs to now expand as much and the torques go up dramatically as the motor gets hot and the studs pull from the case.

Mon Mar 26, 2012 4:47 pm

Nate M. wrote: thom wrote: Slow 1200 wrote: the factory went to 8mm studs for a reason

And that reason is???

(no, seriously, I don't know)

8mm studs will expand at the same rate as the cylinders do. Thus the head torques stay constant and you don't pull studs out of the case.

The 10mm studs to now expand as much and the torques go up dramatically as the motor gets hot and the studs pull from the case.

Do you have any actual documentation of this?

Not to be argumentative; this may be why they did it, as opposed to just a cost cutting measure. It's just that I've never seen any such info- and, in my personal experience, the only studs I've seen pull out of the case are the later 8mm ones. These seem to be the only engines that suffer from "loose heads" as well.

I'd like to see some factory info stating this.

Mon Mar 26, 2012 4:50 pm

Erik G wrote: Since when do you have to machine the case to go from 1500 to 600? I sure didn't.

1641 type 3 - do-able, but won't last more than a couple seasons

The parts suppliers keep trying to tell me they'll fit, too, but in my experience, the 1600 cylinders are just slightly too big. I think that likely the 1500 cases you've not had a problem with have been opened up already.

Mon Mar 26, 2012 9:20 pm

Tram wrote: Nate M. wrote: thom wrote: Slow 1200 wrote: the factory went to 8mm studs for a reason

And that reason is???

(no, seriously, I don't know)

8mm studs will expand at the same rate as the cylinders do. Thus the head torques stay constant and you don't pull studs out of the case.

The 10mm studs to now expand as much and the torques go up dramatically as the motor gets hot and the studs pull from the case.

Do you have any actual documentation of this?

Not to be argumentative; this may be why they did it, as opposed to just a cost cutting measure. It's just that I've never seen any such info- and, in my personal experience, the only studs I've seen pull out of the case are the later 8mm ones. These seem to be the only engines that suffer from "loose heads" as well.

I'd like to see some factory info stating this.

No factory documentation that I can think of. However my experience with the 8mm/10mm studs has been exactly the opposite of yours then; cause I almost never see a stripped out 8mm case saver, but I've seen more stripped out 10mm case holes than I care to think about. There would definitely be an issue if the 8mm studs were threaded directly into the magnesium case, but all 8mm studded cases have case savers from the factory.

There's no money savings or cost-cutting when you consider adding case savers for use with the 8mm studs is WAY more expensive than just screwing in 10mm studs w/o like they used to do. I've never seen a case w/ 8mm studs w/0o CS installed. . . That leaves the only logical reason was thermal expansion and head torques.

Without documentation though, we'll just debate it for eternity. . . :wink:

Mon Mar 26, 2012 9:54 pm

Nate M. wrote: Tram wrote: Nate M. wrote: thom wrote: Slow 1200 wrote: the factory went to 8mm studs for a reason

And that reason is???

(no, seriously, I don't know)

8mm studs will expand at the same rate as the cylinders do. Thus the head torques stay constant and you don't pull studs out of the case.

The 10mm studs to now expand as much and the torques go up dramatically as the motor gets hot and the studs pull from the case.

Do you have any actual documentation of this?

Not to be argumentative; this may be why they did it, as opposed to just a cost cutting measure. It's just that I've never seen any such info- and, in my personal experience, the only studs I've seen pull out of the case are the later 8mm ones. These seem to be the only engines that suffer from "loose heads" as well.

I'd like to see some factory info stating this.

No factory documentation that I can think of. However my experience with the 8mm/10mm studs has been exactly the opposite of yours then; cause I almost never see a stripped out 8mm case saver, but I've seen more stripped out 10mm case holes than I care to think about. There would definitely be an issue if the 8mm studs were threaded directly into the magnesium case, but all 8mm studded cases have case savers from the factory.

There's no money savings or cost-cutting when you consider adding case savers for use with the 8mm studs is WAY more expensive than just screwing in 10mm studs w/o like they used to do. I've never seen a case w/ 8mm studs w/0o CS installed. . . That leaves the only logical reason was thermal expansion and head torques.

Without documentation though, we'll just debate it for eternity. . . :wink:

Case savers were installed for 8mm studs because they pull out was always my understanding. No OEM cases came with case savers that I ever saw, but lots of crate exchange engines did.

Tue Mar 27, 2012 8:03 am

The 73 bug engine I used to run in my 65 Notch has case savers, and it's never been opened up, that I know of. I've had it for over 14 years now.

Tue Mar 27, 2012 8:05 am

Tram wrote: Erik G wrote: Since when do you have to machine the case to go from 1500 to 600? I sure didn't.

1641 type 3 - do-able, but won't last more than a couple seasons

The parts suppliers keep trying to tell me they'll fit, too, but in my experience, the 1600 cylinders are just slightly too big. I think that likely the 1500 cases you've not had a problem with have been opened up already.

Russ converted my high compression 1500 with a 1600 flat top piston kit. Know him, he probably used Mahle parts when he did it. I think he sold the old pistons and cylinders to a 1500 club member. 8) He did that mainly so the engine could be run on today's available gas. :shock:

Tue Mar 27, 2012 8:12 am

Tram wrote: Erik G wrote: Since when do you have to machine the case to go from 1500 to 600? I sure didn't.

1641 type 3 - do-able, but won't last more than a couple seasons

The parts suppliers keep trying to tell me they'll fit, too, but in my experience, the 1600 cylinders are just slightly too big. I think that likely the 1500 cases you've not had a problem with have been opened up already.

no. Specifically a 1500s case that I took the domed pistons out of and ran 1600 Mahle P's and C's. Come to think of it, a 64 1500N motor too, I definetly was the first to pull those motors apart

Tue Mar 27, 2012 8:24 am

Tram wrote:
Case savers were installed for 8mm studs because they pull out was always my understanding. No OEM cases came with case savers that I ever saw, but lots of crate exchange engines did.

The upgrade at the factory was from 10mm w/o CS to 8mm w/ CS. I've been playing with these cars since the late 70s and have yet to see an 8mm case without CS. . . Where this probably became economically justified was through the lack of warranty repairs that had to be done at the dealerships.

8mm studs w/o CS makes no sense. . . They pulled regularly when using 10mmx1.5mm threads. What engineer would then say, "lets use 8mmX1.25mm threads to solve a stud pulling problem."??? That reasoning flies in the face of reason. But an upgrade to case savers to retain the large thread in the case while going with a smaller diameter stud which can expand at a more similar rate as the cylinders, thus reducing the pulling on the threads is genius. Well maybe genius is a stretch, but it's a really good idea. :wink:

Tue Mar 27, 2012 1:34 pm

Nate M. wrote: Tram wrote:
Case savers were installed for 8mm studs because they pull out was always my understanding. No OEM cases came with case savers that I ever saw, but lots of crate exchange engines did.

The upgrade at the factory was from 10mm w/o CS to 8mm w/ CS. I've been playing with these cars since the late 70s and have yet to see an 8mm case without CS. . . Where this probably became economically justified was through the lack of warranty repairs that had to be done at the dealerships.

8mm studs w/o CS makes no sense. . . They pulled regularly when using 10mmx1.5mm threads. What engineer would then say, "lets use 8mmX1.25mm threads to solve a stud pulling problem."??? That reasoning flies in the face of reason. But an upgrade to case savers to retain the large thread in the case while going with a smaller diameter stud which can expand at a more similar rate as the cylinders, thus reducing the pulling on the threads is genius. Well maybe genius is a stretch, but it's a really good idea. :wink:

I pre- date you by a couple years, but I've seen the later cases with no savers. And- I have no idea what you mean by a "lack of warranty work" at the dealers- there was plenty. It just goes with the territory.

Anyway, we can go round and round. What I want to know is if the factory truly went to 8mm studs because they expanded more evenly with the cylinders and heads, or not.

Tue Mar 27, 2012 2:15 pm

Quote: No OEM cases came with case savers that I ever saw, but lots of crate exchange engines did.

I have an original VW service bulletin (in Swedish) dated may 1973 saying that the 1600 engines in Type 1 and 2 are getting thinner studs mounted in threaded sleeves (case savers).

It also says that the studs and case savers can be service installed in older crank cases. Type 3 is only mentioned in the list with part numbers for the updated crank cases.