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Vanapplebomb
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Joined: November 03, 2010
Posts: 5411
Location: Holland, MI
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 Posted: Mon Jul 04, 2022 9:14 am Post subject: Type 4 case inspection and long term stability |
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It still amazes me that even after all these years, these old cases stay as true as they do.
While inspecting the case, I set it up on my mill using 123 blocks under the deck and probed the depth of the bearing saddles.
Note the Z axis reading on the mills DRO. Less than 4 tenths, or 0.0004 inches of variation.
I stoned off the burrs from the case parting line so that I can bolt it back together and check out the main bores for size and out of round.
Then I can repeat the exercise with the cam bore and see how out of whack the deck is relative to the plane created by the crank centerline and cam centerline.
I suspect the deck will be darn close and require very little correction, even after 50 years of use. I only measured 0.0008” of sag at the center of the deck, which is good, even for these cases. Usually the deck sags in a few thou. Being an earlier case, it is a bit stronger than later cases, but still, less than a thou of sag is good news. I would be surprised if I have to take more than 0.002” off each deck to clean it up. 
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1800 Type 4 Berrien 295
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bugguy1967
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Joined: January 16, 2008
Posts: 4341
Location: Los Angeles, CA 90016
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| Posted: Mon Jul 04, 2022 11:43 am Post subject: Re: Type 4 case inspection and long term stability |
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Excellent work! This is way over 99% of builders' heads. This should be the goal--the standard by which we as a group aspire to get to.
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Clatter
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Joined: September 24, 2003
Posts: 7544
Location: Santa Cruz
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| Posted: Mon Jul 04, 2022 12:37 pm Post subject: Re: Type 4 case inspection and long term stability |
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Nice work. Thanks for posting.
I’ve been lucky enough to work with a seasoned guy who has decked a bunch of these cases over the years.
How many thou it takes to get a cylinder register to clean up tells all about the condition of these.
A case that cleans up in a thou or two is a really good one.
Decent ones to use might go up to .003 .004. 005.
A few pretty beaten ones might take up to .008 to clean clear up.
You still won’t see a spread center main that lets light in or fails the ‘carbon paper trick’ at .008 or so.
After that it might get questionable.
Even at .008, a line-bore and back together with a stock motor in a Bus for many tens of thousands of miles now..
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modok
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Joined: October 30, 2009
Posts: 26787
Location: Colorado Springs
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| Posted: Mon Jul 04, 2022 1:39 pm Post subject: Re: Type 4 case inspection and long term stability |
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| bugguy1967 wrote: |
| Excellent work! This is way over 99% of builders' heads. This should be the goal--the standard by which we as a group aspire to get to. |
I'd say 95, 97%? there must A FEW
I've never been of the belief that the case mating surfaces need to be parallel to anything, rather the shape of the two halves just needs to match so they mate properly.
But they were flat to start, so, if they are within .001 of flat after 40 years thats always a very good sign.
And even within that there is a tolerance, can be warped slightly and still come together when the bolts are tightened.
It's hard to define that tolerance because it has a lot to do with shape and the bolt location, but lets say a few thou per cylinder is allowed.
I realized this year that, with subaru and wbx and vw cases, that it may be possible to bring the mains back into tolerance by working WITHIN that tolerance, meaning adjusting she shape of the parting surfaces 
Now that's some FRINGE science right there. |
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Vanapplebomb
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Joined: November 03, 2010
Posts: 5411
Location: Holland, MI
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| Posted: Mon Jul 04, 2022 2:12 pm Post subject: Re: Type 4 case inspection and long term stability |
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| modok wrote: |
I've never been of the belief that the case mating surfaces need to be parallel to anything… |
Same here. I could care less were the parting line falls. Only thing I care about is that the decks are parallel and equal distance to the plane formed by the centerlines of the crank and cam.
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1800 Type 4 Berrien 295
http://www.thesamba.com/vw/forum/viewtopic.php?t=487021 |
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modok
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Joined: October 30, 2009
Posts: 26787
Location: Colorado Springs
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| Posted: Mon Jul 04, 2022 2:21 pm Post subject: Re: Type 4 case inspection and long term stability |
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Cool.
I've wanted to setup some cases like that on a mill to blueprint the lifter bores. |
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Vanapplebomb
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Joined: November 03, 2010
Posts: 5411
Location: Holland, MI
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| Posted: Mon Jul 04, 2022 2:26 pm Post subject: Re: Type 4 case inspection and long term stability |
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| bugguy1967 wrote: |
| Excellent work! This is way over 99% of builders' heads. This should be the goal--the standard by which we as a group aspire to get to. |
Tabari, just so you know, you are one of the builders I aspire to.
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Vanapplebomb
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Joined: November 03, 2010
Posts: 5411
Location: Holland, MI
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| Posted: Mon Jul 04, 2022 2:46 pm Post subject: Re: Type 4 case inspection and long term stability |
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| modok wrote: |
Cool.
I've wanted to setup some cases like that on a mill to blueprint the lifter bores. |
Coaxial indicators are awesome. Stick it in back gear and watch the needle as it sweeps around. Move the table until the needle motion is at a minimum. Easy gets you within 0.0005” without too much fuss. I dropped mine, haven’t replaced it yet.
As far as lifter bores, I have always wondered about over-boring them slightly (not much meet there on a T4) and using a thin sleeve to restore tolerances. If you could make a 1mm wall (maybe 2mm) sleeve, you could use stock lifters and avoid some of the issues with mixing and matching T1 style lifters with T4 cams. Steel would be easy to do it with, but bronze would be a better wear surface… bronze works fine for bushing down to T1 lifters, but you are looking at an awful thin wall to work with T4 lifters. Who knows. It would be interesting to try on a junk case.
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Wreck
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Joined: July 19, 2014
Posts: 1218
Location: Brisbane
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| Posted: Mon Jul 04, 2022 2:53 pm Post subject: Re: Type 4 case inspection and long term stability |
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| nice work . It always amazes me why the type 4 gets such a bad wrap by some people , my 200 HP engine is built with a second hand case from a bus that is still standard on the bearing sizes . |
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modok
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| Posted: Mon Jul 04, 2022 3:02 pm Post subject: Re: Type 4 case inspection and long term stability |
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Oh yeah!
AMC C4 I run has a coaxial indicator built-in, gets fast with practice.
Should be no lifter bore problems with that case, but on some of these type-1 I wonder. |
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Vanapplebomb
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Posts: 5411
Location: Holland, MI
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| Posted: Mon Jul 04, 2022 3:39 pm Post subject: Re: Type 4 case inspection and long term stability |
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I doubt there will be lifter bore issues with this case, but that remains to be seen.
Jake Raby pulls a lot of weight in the industry…. To the point where he can just ream the bores out a few thou and have custom oversize lifters made for him. I don’t have that kind of muscle though. Best I could hope for is to over-bore and make a sleeve for stock sized lifters, short of just bushing down for T1 style lifters.
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raygreenwood
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Joined: November 24, 2008
Posts: 21518
Location: Oklahoma City
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| Posted: Mon Jul 04, 2022 3:42 pm Post subject: Re: Type 4 case inspection and long term stability |
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| Vanapplebomb wrote: |
| modok wrote: |
Cool.
I've wanted to setup some cases like that on a mill to blueprint the lifter bores. |
Coaxial indicators are awesome. Stick it in back gear and watch the needle as it sweeps around. Move the table until the needle motion is at a minimum. Easy gets you within 0.0005” without too much fuss. I dropped mine, haven’t replaced it yet.
As far as lifter bores, I have always wondered about over-boring them slightly (not much meet there on a T4) and using a thin sleeve to restore tolerances. If you could make a 1mm wall (maybe 2mm) sleeve, you could use stock lifters and avoid some of the issues with mixing and matching T1 style lifters with T4 cams. Steel would be easy to do it with, but bronze would be a better wear surface… bronze works fine for bushing down to T1 lifters, but you are looking at an awful thin wall to work with T4 lifters. Who knows. It would be interesting to try on a junk case. |
On very high mileage type 4 cases that were well cared for....I typically see about ~0.0005" to 0.001" of wear....IF they were in tolerance to start with new....but I have no way of knowing. I assume they were.
The other issue is that even good quality new lifters might be 0.0005" "different" though uniform in the set.
Does ~0.001" of wear ...on the high side but in tolerance make a difference on a type 4?
In my opinion yes i think it makes "some"....mainly in a little bit of extra noise and a little bit of variation in oil pressure when hot at highway speeds.....compared to cases I have run with known, slightly tighter lifter bore tolerances.
I will be trying not far off....an experiment with two sets of new lifters of honing the bores uniform (if needed at all)....and electroless nickel plating the two sets of lifters (except for the socket for the PR and the face and oil hole/groove).
That can bring the OD uniformly up to whatever I need, in final OD. After the post bake they will also be harder on the OD surface.
Ray |
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Vanapplebomb
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Location: Holland, MI
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| Posted: Mon Jul 04, 2022 4:19 pm Post subject: Re: Type 4 case inspection and long term stability |
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Ray, you are always full of cool projects and experiments.
One thing about wear, is once it starts, it accelerates. On a cam with gentle ramps, it’s not so bad. But on something with aggressive ramps like a web 494, it can really beat stuff out. The more slop, the more the lifter can edge load the bore and grind away at the wall. It starts snowballing once it goes. I have seen a couple 494 cams do this. It is why I have never run one, although it would be a lot of fun. Those quick lift moderate duration cams really bring out the T4 midrange torque.
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nextgen
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Vanapplebomb
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Joined: November 03, 2010
Posts: 5411
Location: Holland, MI
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| Posted: Wed Jul 06, 2022 6:53 pm Post subject: Re: Type 4 case inspection and long term stability |
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| Wreck wrote: |
| nice work . It always amazes me why the type 4 gets such a bad wrap by some people , my 200 HP engine is built with a second hand case from a bus that is still standard on the bearing sizes . |
I have no idea…
I have noticed that a lot of the strongest opposition comes from people with little to no direct experience with Type 4 engines.
I think a lot of the detractors are hung up on old wives tails from back in the day when T4 engines were adapted for busses. And I can understand that. After all, those were a bunch of inefficient, low compression, hot running engines… lousy tuning, the lot of them. They really were pulled off the scrap heap for one last rodeo, and modified in the worst way to do so.
It’s funny, look at the dates. In 72 the 1.7 was phased out of the 411, and shortly there after was phased out of the 914. Then magically, the 1.7 pops up in 72 for the bus. Same with the 1.8. It was phased out of the 412 in 74. Again, it magically appears in the bus in 74. 1976 was the last year for the original 2.0. Then again, in 76, the 2.0 magically pops up in the bus. Every time a worse reincarnation of the original engine.
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oprn
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Posts: 12730
Location: Western Canada
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| Posted: Thu Jul 07, 2022 4:48 am Post subject: Re: Type 4 case inspection and long term stability |
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| Vanapplebomb wrote: |
I think a lot of the detractors are hung up on old wives tails from back in the day when T4 engines were adapted for busses. And I can understand that. After all, those were a bunch of inefficient, low compression, hot running engines… lousy tuning, the lot of them. They really were pulled off the scrap heap for one last rodeo, and modified in the worst way to do so.
It’s funny, look at the dates. In 72 the 1.7 was phased out of the 411, and shortly there after was phased out of the 914. Then magically, the 1.7 pops up in 72 for the bus. Same with the 1.8. It was phased out of the 412 in 74. Again, it magically appears in the bus in 74. 1976 was the last year for the original 2.0. Then again, in 76, the 2.0 magically pops up in the bus. Every time a worse reincarnation of the original engine. |
Interesting observation but I hesitate to put the blame totally on VW. Remember that that is about the time they were waging war with the great California Emission Gods. Given a bit more time for development and an exemption like the US auto industry got for the "Heavy 1/2 ton" things could have turned out different.
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Vanapplebomb
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| Posted: Thu Jul 07, 2022 5:38 am Post subject: Re: Type 4 case inspection and long term stability |
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True, very true.
Now, keep in mind that this case is only supported by the front and rear of the deck, so these measurements may not mean a whole lot at this point, but it is interesting none the less. Having the case decked, then clamping down at the front and center would be more meaningful. Still surprisingly good for what it is.
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RWK
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| Posted: Thu Jul 07, 2022 6:30 am Post subject: Re: Type 4 case inspection and long term stability |
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Another easy and very accurate way to measure it is to put a test indicator in your spindle and bring down to web and zero it and the DRO, then bring down to the lowest bearing surface (sweep it) until it reads zero again and take reading on DRO, it's the method I use in all my CNC machines for measurements I may need for checking in machine. I have been using this method since the late 70s when DROs started to become common place in tool shops, still use edge finders for X and Y edge pick ups
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Vanapplebomb
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Location: Holland, MI
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| Posted: Thu Jul 07, 2022 6:58 am Post subject: Re: Type 4 case inspection and long term stability |
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That works well, and is also how I align the crank centerline with the X axis on the mill. I got it close with a dial indicator, and then switched to my test indicator. My test indicator is 0.0001” with a +/- 0.008 range, so super touchy to start with. Once it is close, it is awesome.
Any time I measure to the bottom of a bearing saddle I just lay a dowel pin on the surface, then come down with the spindle and touch off on the dowel pin. I put a gauge pin in the spindle to touch off with because it has a nice flat surface. Large borea get a big dowel pin. Small ones get a small dowel. Seems to find home easier that way. For example, the dowel pin I am using for this is 0.7502” in diameter. I just add that number to whatever the DRO reads when zeroed off another reference such as the saddle mating surface.
It turns the mill into a poor man’s CMM. 
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Clatter
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Location: Santa Cruz
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| Posted: Thu Jul 07, 2022 7:08 am Post subject: Re: Type 4 case inspection and long term stability |
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| Vanapplebomb wrote: |
| avoid some of the issues with mixing and matching T1 style lifters with T4 cams. |
You’re worried about the convex face of a type 1 lifter not being compatible with the taper of a type 4 cam lobe?
Or are there other issues I’ve never heard about?
Web will sell you type 1 lifters for use with type 4 cams.
AFAICT Type 1 lifter conversion not only gets you a good shot at sleeving,
It also allows higher lift, due to the bigger lifter face,
A better selection of lifters,
And best of all, lighter reciprocating weight.
Down-side is you can’t easily pull them for inspection anymore i guess.
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