PCV installation

[Rut]

How about a 1275 PCV from a later model? I thought about finding a way to add a little more restriction to my air filter material (it's dry, new foam) and see if that would pull a little negative pressure. I don't know who the mfg of the oval, chrome, Weber air filter is, but I've never seen this type before...not K&N for sure.
Rut

 

[hooey]

if you have a bad oil leek you will never fix it by putting a PVC valve on the motor !!!fix the real problem !!!
but if your just trying to get your motor to have crank case vaccum there are ways, one is use a antibackfire valve like what you would have on a air pump and drill a hole in the ex
and put the valve in it so it works like a carb it will make vaccum and hook it up too your motor vent

 

[Rut]

I'm kinda leaning that way myself, I just wanted to exhaust all options that were cheap and easy before I have to pull the engine. When the motor was rebuilt and modified it was done by a very knowledgable person (checked with the PO) and he said it could only be the rear seal. That said, the benefits of a negative crankcase pressure can't be overlooked from what I've read (been doing a whole week!). I don't know if the crankcase vacuum would just bring the leak up to 'normal' standards. Thoughts?
Thanks, Rut

 

[Trevor Jessie]

Centering that top scroll cap is not a trivial task. I had my machinist do it when he did the align bore/hone on the mains. But when I was doing my final assembly I did some measuring with plastigauge (sp?) and found he had it offset to one side.
I then set about positioning it it myself. I think I got it correct. The car does not leak more than an occasional drop of oil. And this is a forced induction engine.

Since you do not have excessive crankcase pressure, I'm assuming the rings are sealing. Some negative crankcase pressure will help your problem, but it really sounds like something is amuck with that rear scroll.

 

[Rut]

Thanks again! I'm guessing that having been built in 2003 there may a few dry seals. I've used plastigauge before and found it reliable and easy to use. I'll probably go with a little negative pressure in the crankcase and pull the engine for a little re-do on the scroll/rear seal.
Thanks, Rut

 

[Gerard]

Gerard,
Thanks for the detailed reply. The shop that did the work in 2003 has a good reputation, but that doesn't mean they know a lot about this kind of car. I've emailed the po to find out if he has any ideas about the rebuild. If I need to pull the engine I would think that it's pretty straight forward. Do you think it would be worthwhile to drill and tap the boss on the manifold and connect the oil separator to it via a PCV? This would give me some negative pressure, but I don't know if it would correct anything. From what I understand, negative pressure in the crankcase is a good thing regardless. Also, the only oil I see at all is thru the transmission, not any on the oil pan.
Thanks, Rut

I'm attaching two pix of ways to vent. The first is a 1098 with a stock PCV and carbs. You will see that the PVC comes off the balance tube of the intake manifold and connects to the canister of the tappet cover. On a 1275, this canister was moved to the timing cover.

The second pic is of a 1275 with a single HIF44. The PVC is at the right side of the manifold and is attached to a vent on the carb. The other end is teed to the valve cover and timing cover.

It is also possible to add a vent off the mechanical fuel pup opening (or boss, if the casting is closed), but this is usually only done on large over bores or race engines. If you have a block with the pump casting closed, this is best done best done before the engine is assembled. That is the only vent that should be vented to atmosphere and should go to a catch can or have a small filter on it.

Since you have a DGV Weber, I'm not sure the manifold design is right from which to draw a vacuum line. (I have seen a good pic of your setup) However, when I have had DGV's in the past, there was a vent on the underside of the air cleaner. This is what you should probably use in your setup.

If you are only getting oil dripping from the drain hole on the transmission, it is pretty much a certainly that it the rear seal. but there is some possibility that it could be either a poor seal around the oil pump cover or that you may have a cracked rear mounting plate. I have seen many rear plates crack and they typically fracture between the oil pump cover and the opening for the crankshaft. If you had a fracture, you could have the kind of serious leak you describe. If either is the case, I'm sorry to say you will have to pull the engine and investigate the source.

 

[Rut]

Gerard, thanks for the insight and expertise! The DGV intake manifold boss (Pierce Manifolds) is directly below the carb on the outboard side and the oil separator is vented into the underside of the airfilter with no detectable vacuum. Pierce also makes a manifold for the Mini (1275) with power brakes and it has a threaded port on one side to attache the vacuum line. The car uses an electric fuel pump and the original is covered with a plate or 'boss'. This may be a good place to vent the engine as you note. When I pull the engine I'll inspect the rear plate, oil pump, scroll, and anything else associated with a possible excessive leak. As I said before, I'm just looking for a normal leak vs dumping the oil pan in an hour or so. I grew up with TR3s, 4s, 4As, and 6s in the '60s and early '70s along with Triumph Bonnivilles and I'm well aware of these leaks and I'm a good friend of Permatex. While the engine is out would it be advisable to exchange the smooth case trans for a rib case that I have? I really don't know the condition of either trans, but I understand that the rib case has better ratios than the smooth. Thanks again, Rut

 

[bigjones]

The car uses an electric fuel pump and the original is covered with a plate or 'boss'. This may be a good place to vent the engine as you note.

I'm thinking about this also.

Spridgetmania have the breather kit but I'm not sure if it fits my engine (1500). Meantimes, I've just gutted an old fuel pump to see if that would work:

Here it is, back in place:

Gases would escape through one of the pipes but oil would have to get past the membrane (with a 1/4" hole in it) and past the mesh filter.

Have to wait a day for the Permatex Ultra Black to cure before I fire up the engine. Also, I won't be driving the car until the replacement fuel pump (Airtex) arrives from Amazon. If there is an improvement in oil leaks I'll get back.

Cheers and good luck

 

[Rut]

Wow, I never thought of doing that! I look forward to your reply and wish you much success. I'll start looking thru the boxes the po gave me to see if I still have the old pump, if not I may just drill and tap the boss.
Thanks, Rut

 

[bigjones]

Hey Rut,

You're not talking about drilling into the cast iron, are you?

I don't think you are supposed to do that - the swarf stuff would end up in the sump and make a terrible mess of the bearings.

I think the engines prior to the 1275 had a plate you could take off but they never bothered drilling the 1275 as it came with an electric pump from the factory.

Cheers!

 

[sqbsprite]

I was very careful when I built my 1275 and I had the same oil leak. I never had a problem with my 948, but the 1275 is different. Mine had a plate for the mech. fuel pump and I am using a mechanical pump from my 948. I tried making a vent that bolted on in place of the pump and it did not help. I pulled the engine once and dropped the oil pan once and never found anything out of place. The end solution was to use the 1275 valve cover which has a very small vent on it. Then I connected one line from the original fitting for the stock PCV on the intake and ran that to the front timing cover. I put a small inline PCV valve in that hose near the front cover. The problem immediately went away. I too had no measureable crankcase pressure and no blow by. I am using stock SUs with the stock manifold. The fitting on the manifold is nearly 3/8". I thought that would rob too much vacuum, but it did not. If you drill your manifold and connect a line to the front cover, it may solve your problem. Oil will eventually get on your clutch plate if left as is.

 

[Gerard]

I think the engines prior to the 1275 had a plate you could take off but they never bothered drilling the 1275 as it came with an electric pump from the factory.

Not so. Some 1275's did come with an open casting for the a mechanical fuel pump, even though to the best of my knowledge, all Spridgets had electric pumps. the A-series engine is one of the most ubiquitous engines ever made and was used in over 90 different models, so it was likely provided for a different market or different car.

You ARE correct about not drilling the block. I had mentioned that in my previous post.

 

[Gerard]

Gerard, thanks for the insight and expertise! The DGV intake manifold boss (Pierce Manifolds) is directly below the carb on the outboard side and the oil separator is vented into the underside of the airfilter with no detectable vacuum. ...

While the engine is out would it be advisable to exchange the smooth case trans for a rib case that I have? I really don't know the condition of either trans, but I understand that the rib case has better ratios than the smooth. Thanks again, Rut

You might be able to drill and tap a vacuum port on the Pierce manifold then. Try using a 1/4" pipe nipple for ventilation, but restrict the opening to 5/64".

I don't think the smoothcase will handle the torque from the 1275, so yes, I would upgrade f it's a viable trans. Better yet, do a 5 speed. I can fix you up with the kit. I forgot you mentioned you had a smoothcase. Now I'm wondering if you even have the right backplate on the engine? It will make a difference.

https://gerardsgarage.com/Garage/Tech/5speedKit.htm

 

[bigjones]

...Not so. Some 1275's did come with an open casting for the a mechanical fuel pump...

Thanks for setting the record straight - hope I didn't cause any confusion.

Cheers!

 

[bigjones]

...Then I connected one line from the original fitting for the stock PCV on the intake and ran that to the front timing cover...

Did this affect the carb mixture? ie did you then need to richen it up a bit?

Also, what would happen if you left out the PCV valve?

Cheers!

 

[Rut]

Upon further inspection I find that the blanking plate is actually a casting in the side of the block. When the po said he removed the mechanical fuel pump I assumed he meant from the current engine in the car. He must have been referring to the original 948 and when I locate the block I'll check. I really had my hopes up on this one! Now I'm back to looking at a vacuum source and it looks like the best is the boss in the Pierce intake manifold. With all the info on this subject, will it hurt to buy a PCV, connect it to the hose from the oil separator and connect the other end to the new port on the manifold? I assume I need to use the same size nipple that would match up with the PCV just to make it one size hose? If this screws up I can always plug the hole in the manifold. Thoughts?
Thanks again, Rut

 

[jlaird]

How much oil. Think about the cap covering the oil pump. That was my first prob, the soder had cracked when I put a new pump that was too think in there.

I know, you gota pull the engine to check. I did it 7 times before I got a no leaker figured out.

 

[Rut]

Jack,
I think it's way too much oil for just a negative pressure problem so my next step will be to pull the engine. I cleaned out my shop and moved the car there today so it won't be in my wife's way so I have more time to work on it. I pulled the bonnet off with a pully system I set up and I have more access to the engine and all things Bugeye. She's up on jack stands too and I have access to the underside as well. I've got to buy something to pull the engine/trans and I need suggestions, used to do it at the farm with an old swingset. Since she was up in the air I decided to look at the brakes, boy what a mess! The lines are rusted and they broke apart while I was trying to remove the drums. The caliper cylinders are rusted and I will probably buy some rebuilt ones. Suggestions on any of the above?
As always, thanks for everyone's help.
Rut

 

[jlaird]

Go to Harbor Freight and buy an engine hoist. about 100 bucks. Works a charm.

 

[jlaird]

New line sets are available from Moss even. Drew for example had good results.