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Crankcase Ventilation

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BillHoltzman Bill Holtzman
Annapolis, Maryland, USA   USA
I recently acquired a 1973 Midget 1275. After going over it I noticed all of the emissions stuff is removed. A previous owner put a valve cover from a earlier engine on it, removed the charcoal canister, the PCV valve, and took the wye 3 hose connector off, and ran a hose from one carb to the other. My question is, should I put the wye fitting back on, the car runs poorly, with a high idle, and can stall from slight acceleration. From what you all can tell from pictures, is there anything that I missed that is incorrect or needs fixed?
Tell me what you think,
Bill Holtzman

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73midget Avatar
73midget Chris Edwards
Carrollton, Texas, USA   USA
i'd be more concerned with where the hose is from the oil catch can on the front timing cover. a 1275 should have a port coming off the front (looks kind of like someone welded a soda can on the front of the engine.). This should have a hose that goes to a y fitting with the cross over hose that you added. The system uses vacuum from the carbs to create a slight negative pressure in the crankcase which reduces oil leaks.

it's british, so it will leak either way... but without that negative pressure, it will GUSH.

BillHoltzman Bill Holtzman
Annapolis, Maryland, USA   USA
The hose from the oil catch can is not connected to anything. If I was to put the wye fitting back in and properly hook it up, would I slow the idle?
Thanks,
Bill Holtzman

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ice Avatar
ice Gold Member Larry Ice
Lawrenceville, GA, USA   USA
Bill, have you done a static tune up on the timing, points, valves before trying to get the engine running smoothly? If not, suggest you do that before putting much work into the carbs. Might also check if you have a vacuum leak on/around the carbs and intake.
If the Y connector is still attached to the carbs but not the vent on the timing cover for sure you have a pretty good sized leak.



Iceman

Atlanta GA

60 AH MK1
62 AH MKII
67 Midget
71 Midget

geezer Avatar
geezer Silver Member charles durning
Magee, Mississippi, USA   USA
1958 MG Magnette ZB "Chick Magnette (sold)"
1967 Morris Minor 1000 Saloon (2-door) "Marvin"
1974 MG MGB GT
The "Y" fitting is on the atmospheric side of the throttle plates. That will not affect the idle but it will affect the mixture which can affect the idle. Other things that can affect the idle is ignition timing as well as the throttle stop screws, sticky throttle cable, vacuum leaks, etc..



Who's version of right are we talking about? When you get 10 LBC owners in a room you'll get 12 different answers.

westfield7 Silver Member Michael Wooten
In the path of Totality, SC, USA   USA
1983 Westfield Seven "Green Car"
Completely off topic, but that is a very interesting use of color.

matmire Avatar
matmire Matt Meyer
Studio City, California, USA   USA
after verifying correct valve lash clearance, timing, spark, etc. These are the things I can think of based on your photos...


-I think I would reconnect the "Y" fitting, at least to take some of the non-stock variables out of the equation. FYI, your car would not have had both a PCV valve and a "Y" fitting. It was one or the other. 2 different solutions to crankcase ventilation.

-It appears your car is using manifold vacuum for the distributor advance. If your front carb has a vacuum nipple (just behind the float bowl) make sure it's plugged. That would be a big vacuum leak. (hopefully your dizzy is actually a manifold vacuum version)

-The front float bowl venting tube appears to be disconnected. And as I understand it, the vent tubes need to run always downhill from the bowls, not over the top of the carbs, and with no peaks and valleys. That way, if the carbs flood the fuel will flow out fully and not sit in any "valley".

-I think I would remove that hose clamped "plug" in the intake manifold and seal it properly with a correctly fitted plug. (mostly just to tidy things up, but it could be another source of vacuum leaks)


of course, that all leads to tuning the carbs.

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BillHoltzman Bill Holtzman
Annapolis, Maryland, USA   USA
Thanks everybody for the helpful and detailed advice, this should get me on my way! Not my color choice, the idiot before me did that...

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