View Full Version : Alloy Valve Cover

06-02-2013, 04:13 PM
I'm planning on buying an alloy valve cover, and had a few questions before I pull the trigger. 1. Does the regular cork valve cover gasket work with these? 2. Have you had to drill any holes in the cover or filler cap in regards to the PVC system?

Trevor Jessie
06-02-2013, 04:23 PM
Yes I use a rgular cork gasket. I didn't need to drill any holes for my application.

06-02-2013, 06:44 PM
My must have list would include: the cap opening on top having the proper fitting for an OEM vent cap...The bottom would have gasket guides on the inner rim to help keep it in place..

06-02-2013, 08:31 PM
And glue the valve cover gasket to the valve cover. Worked well for me.

06-03-2013, 11:35 PM
Stiple the corner's of the valve cover with a center punch before you glue it in place. Lots of little indentation's will help hold the gasket where it usually pulls away first.


06-18-2013, 09:46 PM
Jim, as mentioned the regular cork gasket works just fine. And, so does gluing it on. I glued the gasket to the cover, then smear a thin film of grease to the side that contacts the head and it makes it real easy to remove the cover without damaging the gasket. A rap with the palm of your hand and the cover pops off with the gasket intact. Some covers come with a vent tube, but if not, just make sure you use a vented cap.
I see you are in Atlanta. You may not be the club type, but we have an active MG club. If interested, see: www.peachtreemg.com (https://www.peachtreemg.com)
If not, I'd still like to meet you. Always nice to meet other Midgets in the area. I'm in the Grayson area.

06-19-2013, 11:36 AM
A friend put this Edelbrock (4211) breather on his 1275. Been thinking about modifying mine this way (with the notion that breathing is good - and I can still set up PVC through the oil separator to the intake manifold). This breather requires drilling an assortment of holes through the side of the cover.

06-19-2013, 11:55 AM
I would use a vented cap or a standard 'breather' that fits the oil fill hole before I modified my alloy cover. It does the same thing for less money and work. My experience is that the oil separator on the timing cover connected to a good vacuum source, pcv valve or vented carbs and a NON vented cap gives the most negative crankcase ventilation to control the rear scroll seal oil leak. Just my experience, but easy to test out.

06-19-2013, 12:03 PM

06-19-2013, 10:19 PM
I had sort of the opposite experience, with more issues when I had an unvented valve cover. They seemed to go away after I put a vented cap and a small breather on the cover. I don't think you can have too much crankcase ventilation - seems like anything you can do to keep the crankcase pressue down will help keep from blowing oil out. Of course, this is just anecdotal. Would be interesting to actually measure crankcase pressure (and maybe oil loss!) with different set-ups.

06-20-2013, 01:30 PM
Theoretically you want to minimise, but not eliminate the venting. The crankcase should have a source of vacuum, either a draft tube, or from the intake manifold or carbs. Vacuum should be applied to the block side covers, timing chain cover, or both. Then the valve cover should either have a vented cap or a vent pipe that is connected to the carb air filters or it own dedicated filter. The vent should have a small hole on the order of 1/8" or smaller (I need to look up the right size).

The vent is sized to regulate the vacuum on the crankcase. No vent = too much vacuum, vent too big = no vacuum.

I spent a lot of time reading about this stuff to minimise leaking from my 948. The engine is not back in the car yet so I don't know how well it works.

06-20-2013, 02:08 PM
i don't know if the issue is the same for the 948 as it is for the 1275, but I would guess it is. My 1275 started off with a Weber on a Pierce manifold and an alloy valve cover, vented. It leaked like the Exxon Valdez! The only vacuum source was the timing cover oil separator piped to the underside of the air filter assembly. I drilled and tapped the manifold boss and connected the oil separator to it via an elbow and the leak went away, but the engine pulled too much vacuum and it smoked like crazy. I reduced the size of the hose going into the manifold and finally found a decent balance, but still not satisfactory. I moved to the early SU HS2 setup using a pcv valve and the leak got better, but not stopped. I closed off the oil fill on the valve cover and all of the vacuum from the pcv valve was able to slow the leak even more. I replaced the early HS2s with later ones that have the built in vents using the y pipes from the oil separator. Better still, but not perfect with a few drips remaining. I resealed the valve cover to reduce any air leaks and that slowed the rear leak even more with no smoke. I imagine this engine will always be a leaker, but it is much more manageable with the later SU HS2s.

06-20-2013, 11:58 PM
Correct PCV and good, well set up, scroll seal on the rear of the crank is necessary. But, you can always expect a little dripping.
The stock cap should fit the alloy valve cover if its the one commonly sold on e-bay.


06-21-2013, 08:54 AM
A friend put this Edelbrock (4211) breather on his 1275.
27763 The engine builder of my new 1275 put one of these on. He says he does it to all his rebuilds. It looks good opposite the Weber DGV .
my two cents

06-23-2013, 01:28 PM
Thanks Lads! I'll probably purchase an alloy cover within the month. My pressed sheetmetal one is allowing too much oil seeping around it when topping up, plus it looks blah. @ Jack...we've actually met before at a couple of shows, and on Ray McCaleb's garage tour back in 2008. I was a member of the Peachtree club but dropped when time to renew because of limited time to put toward club events. Some years I can make a couple of events, others like this year I can't even make it to a single one due to other obligations. Appreciate the offer and the invite though!

06-23-2013, 02:43 PM
X2 on comments above re gasket prep. I like cork. I use a stock plastic vented cap. I like the look of the "T" nuts.
You might need to notch it if your head has too many studs. This one had to be notched in the front a bit for a Longman GT head.
I also vent from the old fuel pump site and the front cover. No PCV or gulp valve. Minor drip after a run. No biggie.
Excuse the nasty dirty condition. This was during an intake change-over.

06-23-2013, 05:37 PM
Jim, as to oil seeping from the valve cover during topping up, I have noticed (and I hope this is a general observation and not a problem only I have!) that the 1275 head percolates oil very slowly and when changing oil, if I pour it in too fast, it will fill up the valve cover until it slowly drips through. So, if you do have an ill fitting gasket, it could leak out then. Pour slowly!

Sorry I didn't remember you. I have trouble remembering what I did yesterday, much less in 2008! But, I do remember the garage tour. FYI, Ray is getting out of the LBC business now, just sold his Midget under construction, including all parts and an engine Hap built for it, on ebay.

06-24-2013, 05:37 PM
I think part of the oil seep when filling is a faulty gasket, and some warping of the sheet metal valve cover. Fingers crossed an alloy unit with new gasket will resolve.

No worries on remembering. I have trouble nowadays getting into a room and remembering what I went in there for.

I'd heard Ray was getting out of LBCs, and saw his Spridget project on Ebay a while back. I suspected he may lose interest when he bought that BMW M3. Do you know if he still owns the white Midget & TR3?

06-25-2013, 03:55 PM
Nope, think they are both gone. Think he is now into building R/C model planes!