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914World.com _ 914World Garage _ One step forward, two steps back...
Posted by: JOEPROPER Jan 29 2018, 06:15 PM
So I got my '75 2056 back from the machine shop and began dressing it up. I tested and cleaned some fuel injectors and found that I have 4 good ones. 
As I got to fitting the cooling tins, I found that the cylinder heads are on backward. CHT sensor is supposed to go on the 3-4 side... 
I think I've seen this problem on here somewhere but can't find it now. The immediate concern is the wire location for,the CHT sensor. I'm thinking the only correct way to fix is to take everything back apart and switch cylinder head sides.
If I had ample time to work on this, I wouldn't be so frustrated. 
Posted by: Dave_Darling Jan 29 2018, 06:23 PM
You can also cut a hole in the left-side cylinder tin and fab a wire with connectors on the end that will let you plug the HCT into the correct plug of the FI wiring harness.
That's less optimal, but it evidently does still work.
You might also be able to drill and tap the correct size hole in the now right-side head.
--DD
Posted by: Mikey914 Jan 29 2018, 07:02 PM
#3 is the hot one so, best off it, but some imput is better than no imput.
Posted by: JOEPROPER Jan 30 2018, 07:58 AM
You can also cut a hole in the left-side cylinder tin and fab a wire with connectors on the end that will let you plug the HCT into the correct plug of the FI wiring harness.
That's less optimal, but it evidently does still work.
You might also be able to drill and tap the correct size hole in the now right-side head.
--DD
Thanks for the suggestions. I will look at the 3-4 cylinder head and see if i can drill and tap it. I guess if I mess it up, I can look into that HAM cylinder GB that's floating around here.
Posted by: theer Jan 30 2018, 08:24 AM
That's a bummer. Agree with Mark, though: #3 is the hot one.
Are the heads really identical except for the CHT threaded hole? I never looked that closely... intakes? exhaust ports?
Anyway, by the time you drill & tap you can have switched the heads. It's not that hard, especially on a new build and if you still have with the engine out and the tin off.
There you go: free advice - it's worth exactly what you paid for it.
Good luck.
Posted by: Mikey914 Jan 30 2018, 11:55 AM
That's a bummer. Agree with Mark, though: #3 is the hot one.
Are the heads really identical except for the CHT threaded hole? I never looked that closely... intakes? exhaust ports?
Anyway, by the time you drill & tap you can have switched the heads. It's not that hard, especially on a new build and if you still have with the engine out and the tin off.
There you go: free advice - it's worth exactly what you paid for it.
Good luck.
Other than the probe threading I believe so.
Posted by: Racer Chris Jan 30 2018, 01:02 PM
IMO its not worth trying to drill/tap the other head. Cut a hole for the wire in the other tin and extend the wire.
Which head it goes on makes no difference to the FI brain as it's only a warm up enrichment device. Once it's above a certain temp it has no more influence on the fuel mixture.
Posted by: JOEPROPER Jan 30 2018, 06:01 PM
IMO its not worth trying to drill/tap the other head. Cut a hole for the wire in the other tin and extend the wire.
Which head it goes on makes no difference to the FI brain as it's only a warm up enrichment device. Once it's above a certain temp it has no more influence on the fuel mixture.
That's what I did. I don't have a 10mm x 1.0 tap anyway...
Posted by: malcolm2 Jan 30 2018, 06:22 PM
IMO its not worth trying to drill/tap the other head. Cut a hole for the wire in the other tin and extend the wire.
Which head it goes on makes no difference to the FI brain as it's only a warm up enrichment device. Once it's above a certain temp it has no more influence on the fuel mixture.
I was thinking warm up only too. So it is not the end of the world, just not perfect.
HAM reworked my 1.8 heads and He forgot I was using FI and closed up my hole.
So I had the same issue, but caught it before installation. So I did the drill and tap thing on #3. I think I got the drill and tap from the same place. The tap is limited so the hole really needs to be the correct size.Posted by: r_towle Jan 30 2018, 06:53 PM
I would just pull the heads and swap them.
rich
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