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Wed May 05, 2021 5:27 am

I am trying to fit heat exchangers on my Type 4 2.0 engine that I am rebuilding (for a bus). I am using 2l AMC Ham heads

Among 3 sets of heat exchangers I have one good set.

On the 1/2 side, the exhaust flanges foul of n the casting even with the studs removed.

The exchanger did fit on an old 1700 head. The exchanger isn’t bent.

One of my junk exchangers fit perfectly. The flanges and tubing sizes appear to be different. They are both OG VW. It’s hard to see the differences in the photo.

I have never read anywhere of differences in this type of heater boxes and was under the impression that they were pretty much interchangeable as the oval exhaust ports remained the same until he square port heads came out.

I was wondering if anyone else has dealt with this problem. It looks like clearancing the casting a little would allow it to fit.

Wed May 05, 2021 6:24 am

I have had problems with the studs fitting the holes.

All I did was elongate the holes in the header.

The only heads I ever worked with were stock.

Ray will be on this one soon I am sure and will have some answers.

Wed May 05, 2021 7:15 am

nextgen wrote: I have had problems with the studs fitting the holes.

All I did was elongate the holes in the header.

The only heads I ever worked with were stock.

Ray will be on this one soon I am sure and will have some answers.

Thanks. The studs are often a tight fit and it gets worse when they get dinged up. Mine are in good shape and came out of the heads easily. I used to install the heat exchangers after the engine was installed which often results in a bad seal. Glad I am checking them on the bench this time.

I have run these heads before with EMW j-tubes. The lugs for the studs have larger holes and are more forgiving to install.

Wed May 05, 2021 5:38 pm

orwell84 wrote: I am trying to fit heat exchangers on my Type 4 2.0 engine that I am rebuilding (for a bus). I am using 2l AMC Ham heads

Among 3 sets of heat exchangers I have one good set.

On the 1/2 side, the exhaust flanges foul of n the casting even with the studs removed.

The exchanger did fit on an old 1700 head. The exchanger isn’t bent.

One of my junk exchangers fit perfectly. The flanges and tubing sizes appear to be different. They are both OG VW. It’s hard to see the differences in the photo.

I have never read anywhere of differences in this type of heater boxes and was under the impression that they were pretty much interchangeable as the oval exhaust ports remained the same until he square port heads came out.

I was wondering if anyone else has dealt with this problem. It looks like clearancing the casting a little would allow it to fit.

Not really hard to see at all. The exchanger laying on top is a wider oval with fatter castings. The one on the bottom is a narrower oval...and looks more like a 1.7L heat exchanger.

What are the part numbers of the exhcangers you have? What are they from?

Ray

Wed May 05, 2021 7:56 pm

I couldn’t find a part number on them.
They are both marked 4 L on the side.

I know that they are both off buses and have the exact same tin for 73-74 buses. Everything I have read has said all the oval port exhaust systems are interchangeable. The other side fits without any issues. I can see that the flanges and tubing are slightly larger.

I thought that clearancing the heads would be ok. I haven’t finished but they just about fit. Never knew that there were differences in sizes between the same style of exchanger and tin.

Is doing this ok? I have been taping up a copper gasket to avoid nicking the port.

Thu May 06, 2021 3:47 am

The exchangers that don’t fit are stamped 021 286 B and C as well as GE.

Thu May 06, 2021 4:10 am

The exchangers that don’t fit are stamped 021 286 B and C as well as GE.

Fri May 07, 2021 6:57 am

Whoo.. Welcome to the club..!

Not sure if it's AMC heads or what.. But i could swear they have a different center-to-center measurement between the exhaust ports sometimes.

Check my 'cheap junk' thread again - there's a bunch of details about this..
Sometimes multiple solutions are required.

The two different size port flanges in this pic..
Could you measure them?
What do they look like if you set the same gasket on each?

I do know that the 411/412 small 'pre-heater' boxes came in a small and a large.

Perhaps that smaller set is from one of the early early 1.7s?
Notice no EGR port..

Fri May 07, 2021 9:46 am

Clatter wrote: Whoo.. Welcome to the club..!

Not sure if it's AMC heads or what.. But i could swear they have a different center-to-center measurement between the exhaust ports sometimes.

Check my 'cheap junk' thread again - there's a bunch of details about this..
Sometimes multiple solutions are required.

The two different size port flanges in this pic..
Could you measure them?
What do they look like if you set the same gasket on each?

I do know that the 411/412 small 'pre-heater' boxes came in a small and a large.

Perhaps that smaller set is from one of the early early 1.7s?
Notice no EGR port..

AS far as I know....no 411 or 412 ever came with internal cast fins on the HE's. The external sheet metal on 411/412 HE's is far too small for those finned castings.

I say I have not "SEEN" any. But.....there are no less six part numbers in my book.

411 and 412 through August of 1972 (as far as my parts book goes) had a few different part #'s.

(figure #5) 021 256 091 B -left hand ...to engine # V 0 100 000
021 256 091 C- left hand....FROM engine #'s W/Z/EA 0 000 001
(figure #4) 021 256 091 H- left hand....listed a M202 which is increased warm air heating from the fan shroud. So...its possible this one had internal work but it has a different shroud connection.

(figure #7) 021 256 092 B-right hand...to engine # V 0 100 000
021 256 092 C- right hand ....FROM engine #'s W/Z/EA 0 000 001
(figure #6) 021 256 092H- right hand....listed as M202

I also think that the 021 286 part number marks it as bus or vanagon.

When I google 021 286 091B....I dont get any HE's...so I think his part # may be wrong.

Ray

Fri May 07, 2021 10:06 am

Clatter wrote: Whoo.. Welcome to the club..!

Not sure if it's AMC heads or what.. But i could swear they have a different center-to-center measurement between the exhaust ports sometimes.

Check my 'cheap junk' thread again - there's a bunch of details about this..
Sometimes multiple solutions are required.

The two different size port flanges in this pic..
Could you measure them?
What do they look like if you set the same gasket on each?

I do know that the 411/412 small 'pre-heater' boxes came in a small and a large.

Perhaps that smaller set is from one of the early early 1.7s?
Notice no EGR port..

Thanks Clatter,

I did find my way back your cheap junk build (I often do). The outer diameter of the flange I’m trying to fit is like 1.25mm wider longways and .25mm short ways.

I have been clearancing the heads with a taped gasket in the exhaust port...just sneaking up on it; grind, check repeat. I have kind of gotten over my fear of modifying stuff to make it fit. Can’t avoid it unless you don’t care if it fits.

I found an old gasket that is thicker and rounder. There is wiggle room with both. Stock heads might have had more clearance but who knows really. Like body panels from different manufacturers; they’re just not gonna fit without some dicking around.

Anyway, I’m just about there. Gonna schmeer some grease in there and see how it squishes, grind accordingly using the CH standard.

Fri May 07, 2021 10:26 am

I have found the T-4 manifolds to be superior the T-1, once installed correctly.

I also like the bottom mounting locations vs the T-1 coming out each end.

Are you going to use them for heat?? Or just mounting them with the fins attached????

Recently there was post on removing the heavy fins. I was lucky mine were stock straight headers no fins..

Fri May 07, 2021 10:35 am

Yes, I’m using them for heat. I thought it would be “fun” to get the stock heat working again. I already have j pipes. I have repaired or replaced a lot of the tubes, heater tins and parts.

Fri May 07, 2021 12:58 pm

OK very nice job--- I am in Rockland County 35 north of NYC on the Hudson River.

Plattsburgh, Yes if you are driving in the winter, ha!!!! You are up near Canada.

I ripped out my heater channels and used 2" ( If I remember correctly ) Galvanized pipe bolted to the frame just for extra support.

Looks like you are going to run some heat thru yours??

Fri May 07, 2021 6:25 pm

I don’t drive in the winter and really don’t need the heat as I have a gas heater but I have been slowly finding all the pieces and thought it would be nice to have. Btw, I grew up in Rhinebeck and a lot of my family are from Poughkeepsie... both still considered upstate.

Sun May 09, 2021 9:15 pm

I drill out the flange holes 1 size or so. Then check their fit. If pipes need tweaking heat and a cheater pipe (appropriate size).

Once I'm sure they are straight. I use Loctite 518 on each side of the copper gasket. Then mate up the exchanger. Apply liberal amount of copper seize to studs.

After each heat cycle I'll check the torque ( (4-5 good cycles)

After that resist any temptation at re-torqueing them or risk pulling a stud/s.

Mon May 10, 2021 7:15 am

I believe if you are going to use anti seize, it is on the exhaust heads studs. Breaking a stud off on a head with the engine in the car, can go from simple to engine removal and on from there.