Very interesting. I'll probably do that setup. Looks like you have two different systems?
2240310 1972 BMW 3.0cs
- Thread starter boonies
- Start date
Scott,
it is one "system"
The table is set up with the following:
Buckets on the front row: cleaning agent (to be heated), then two rinse buckets. The rinse buckets were to be separated, one for the post zinc plating bath and then for post chromating bath.
I no longer use the bath, just a spray bottle to rinse the parts off as I take them out. I do pull the anodes when not plating and keep them in one of the front buckets.
If I ever re-make the top I will likely eliminate those front buckets altogether. I really don't use the cleaning agent bucket much either as I have an ultrasonic cleaner and a bead blast cabinet that do the work more effectively.
Buckets on the back row: Muratic acid bath, zinc plating bath, yellow chromate, blue/clear chromate
On the very back is the power supply for the zinc plating process.
it is one "system"
The table is set up with the following:
Buckets on the front row: cleaning agent (to be heated), then two rinse buckets. The rinse buckets were to be separated, one for the post zinc plating bath and then for post chromating bath.
I no longer use the bath, just a spray bottle to rinse the parts off as I take them out. I do pull the anodes when not plating and keep them in one of the front buckets.
If I ever re-make the top I will likely eliminate those front buckets altogether. I really don't use the cleaning agent bucket much either as I have an ultrasonic cleaner and a bead blast cabinet that do the work more effectively.
Buckets on the back row: Muratic acid bath, zinc plating bath, yellow chromate, blue/clear chromate
On the very back is the power supply for the zinc plating process.
So, I have seen some zinc chromate parts that are matte finish, and some that are very shiny. Ids that a result of starting with a polished part and then plating it? Even your cast parts up in post 75 and 77 look pretty shiny...
I add a brightener to the zinc bath. The zinc comes out very bright and the chromate is then bright as well. It dulls over time as a result of the oxidation process.
Last edited:
what happens if you ceramic coat the freshly zinc'd pieces ... will it stay 'bright'? curious ... if that is something we should do to zinc'd parts. thinking of things like the yellow zinc washers on the front of the car or pieces like the trunk latch or even door latches.
Not sure about ceramic coat, but possibly...anything that creates a barrier to the exposure to oxygen, water or petroleum products. So something like cerokote or similar. I like cerokote, but it is a PIA to drag out the spray gun every time i want to coat something so I don't always do it.
So far I am treating it as a future Lance problem or a problem for the next owner...
So far I am treating it as a future Lance problem or a problem for the next owner...
I nickel plated the door strikers and latches on my 635. Those held up
For sure it will inctease the life span of zinced parts if you coat them.
My local company even offers it as a service, it's called a "sealer".
That adds about 20% on the "salt spray test" results.
I expext that Ceracote will be a quite succesfull coating, as it is thin and thus likely doesn't tear up when tightening nuts and bolts. But that's theoretical. I will gladly accept practical experiences!
I need to vent.
I have been on the chase to get my coupe converted to triple Webers after my spring debacle with the air cleaner hold down (see earlier post).
I am now taking the Webers back off for the third or fourth time. Vacuum leaks between the manifold and the head.
rand new Weber 45 DCOE’s having lean backfire through the carbs at idle and no-load part throttle. I use starting fluid and find vacuum leaks when the engine is colder, but as it warms they improve slightly, but not sufficiently to resolve the lean backfire at part throttle.
The first installation the intake to head gaskets were dry. The next installation I checked the manifold sealing surface with a straight edge and then coated both sides of the gasket with Reinzoplast blue sealant.
Tomorrow I will pull off the carbs and manifolds again. I will get out the sheet of glass and sand the manifold surface across the glass to see if there are identifiable low/high spots (of course I cannot do that with the head itself) and remove them. Once the surface is checked I will coat new Victor Reinz gaskets with Gasgacinch (recommended by Top End Performance).
I am fighting the urge to go back to the down draft 38’s which ran flawlessly, but I really don’t want to do that. The hood doesn’t close properly because the air cleaner sits high due to the added height of the air cleaner adapters.
I guess the positive is that the work is getting faster as I am well practiced. Now, where did I drop that 12mm socket…no seriously, it landed somewhere on the sub-frame and I am going to need it!
I have been on the chase to get my coupe converted to triple Webers after my spring debacle with the air cleaner hold down (see earlier post).
I am now taking the Webers back off for the third or fourth time. Vacuum leaks between the manifold and the head.
rand new Weber 45 DCOE’s having lean backfire through the carbs at idle and no-load part throttle. I use starting fluid and find vacuum leaks when the engine is colder, but as it warms they improve slightly, but not sufficiently to resolve the lean backfire at part throttle.
The first installation the intake to head gaskets were dry. The next installation I checked the manifold sealing surface with a straight edge and then coated both sides of the gasket with Reinzoplast blue sealant.
Tomorrow I will pull off the carbs and manifolds again. I will get out the sheet of glass and sand the manifold surface across the glass to see if there are identifiable low/high spots (of course I cannot do that with the head itself) and remove them. Once the surface is checked I will coat new Victor Reinz gaskets with Gasgacinch (recommended by Top End Performance).
I am fighting the urge to go back to the down draft 38’s which ran flawlessly, but I really don’t want to do that. The hood doesn’t close properly because the air cleaner sits high due to the added height of the air cleaner adapters.
I guess the positive is that the work is getting faster as I am well practiced. Now, where did I drop that 12mm socket…no seriously, it landed somewhere on the sub-frame and I am going to need it!
Found the 12mm, somehow lodged safely in the little tray at the back of the front subframe!
All pulled apart, a fairly quick process. I then got out my glass panel with various grades of sandpaper affixed, sprayed them down with WD40 and went to work.+
I did find that each of the manifolds had some uneven surfaces on both sides, on the picture below you can see some of the bright surface that had not been touched by the sanding process. This is not as accurate as a machine shop by any stretch of the imagination, but should be much closer tolerance now. We will see...
All pulled apart, a fairly quick process. I then got out my glass panel with various grades of sandpaper affixed, sprayed them down with WD40 and went to work.+
I did find that each of the manifolds had some uneven surfaces on both sides, on the picture below you can see some of the bright surface that had not been touched by the sanding process. This is not as accurate as a machine shop by any stretch of the imagination, but should be much closer tolerance now. We will see...
the gasket should be able to seal any leaks now. Don’t give up on the triples!
Pittraider18
Well-Known Member
This is my next step too! I noticed how poor the casting was on whatever mystery manifolds I have that came with my spare M30. Need to level them out for sure.
That looks like a Karsundpartz manifold. Same as what is sold by Pierce. The castings are pretty rough!
It is a karzundpartz. Based on my “machining process “ I would urge others to do some work to dress them up before installation.
I have everything reinstalled, following the instructions for the gasgacinch product to let it sit for 24 hours. Fingers crossed…
I have everything reinstalled, following the instructions for the gasgacinch product to let it sit for 24 hours. Fingers crossed…
Yep. I'll be doing that unless I make my own manifolds. Thanks!!
I am tapping out.
I fired it up this morning after having all the carbs and manifolds off and I still have a vacuum leak on the front manifold at the connection to the head.
I am going to revert to the Weber 38/38 down-draft set up and get it running well as I explore next steps. I would love to have the side-drafts, but I have to get it running and put some miles on it again.
I fired it up this morning after having all the carbs and manifolds off and I still have a vacuum leak on the front manifold at the connection to the head.
I am going to revert to the Weber 38/38 down-draft set up and get it running well as I explore next steps. I would love to have the side-drafts, but I have to get it running and put some miles on it again.
I ordered gaskets and some other bits that I need for the installation of the stock manifolds last night. With a little time on my hands today I decided to dry-fit the first manifold, the one that seemed to be giving me problems. The face seemed to match up well, although I still need to see if I can fit a feeler gauge in between it and the head.
What I did find is that the mounting boss machining is not square. There is a difference of ~.75 mm from the top to the bottom on each of the mounting points and not square side to side. I am wondering if this taper could cause the manifold to not pull completely tight. My machine shop recommended another firm that could do the work squaring up the mounting boss to the mating surfaces.
What I did find is that the mounting boss machining is not square. There is a difference of ~.75 mm from the top to the bottom on each of the mounting points and not square side to side. I am wondering if this taper could cause the manifold to not pull completely tight. My machine shop recommended another firm that could do the work squaring up the mounting boss to the mating surfaces.
Oh Don't give up yet!
The Karszundpartz units are really rough. They could be helped by flycutting the mating surface. I have designed a 3D model that might work.
Super bespoke with your car's name part of the unit. I am probably going to get these printed in aluminum, cheaper and better quality than sand casting.
Last edited:
Thanks Scott, I am interested when you are ready. I was also looking at the intake manifolds from dbilas as an option.
Pretty good price on those!
Still trying to identify a cost effective way to fabricate my version. Xometry wants about $400 each for aluminum printed parts.
Most of the sand cast parts are going to be about like the Karsundparts and dbilas parts. Looks like the dbilas parts are SLIGHTLY nicer.
I think any sand cast part, and possibly a metal printed part will need to have the flange surfaces milled. I'll probably start there with the Karsundpartz units, just to get the car operational. That will be next year sometime.
I'll need to add a boss for the vacuum fitting... Has anyone explored if having one carb with the vacuum fitting causes any issues? Seems like as the brake booster cycles it would momentarily change the AFR for that one cylinder. If so, would it be better to spread that effect out across all six intakes?
In the meantime I ordered a set of three of the above units in ABS, to use as a fit-check. ABS was $53 for three!