TR2/3/3A Alloy valve cover--new twist

[mmgwhite]

Recent previous thread on changing from stock to alloy valve cover led me to go ahead and change it out.
I bought a polished version without the side vent from TRF
Arrived today but strangely won't fit. That is until you turn it around backwards with the oil fill port aft rather than fore.
On close inspection, it appears designed that way with the hold down holes drilled slightly off center such that you simply
cannot mount it with the oil fill cap to the front.
Is that normal?
Looks ok
functions fine. doesn't leak.
Any comments?

 

[TR3driver]

What part number did you order? It sounds like you have a TR4 cover, and AFAIK TRF doesn't carry alloy covers for TR3 any more. They even took the part number out of the data base.

 

[TomMull]

What part number did you order? It sounds like you have a TR4 cover, and AFAIK TRF doesn't carry alloy covers for TR3 any more. They even took the part number out of the data base.

Agree with Randall but If you can fit a vented cap on it, I can't think of why it wouldn't work. Tom

 

[PeterK]

When you find a vented breather cap to fit a TR alloy cover, please post it here. Never seen one for sale.

 

[mmgwhite]

I ordered part number VCTR41/CRK-
Guess I didn't notice it has TR4 imbedded in the part number.
Seems to seal nicely. It is pretty.
Will the engine vent satisfactorily out of the overboard vent pipe?
Does it require a vent from the top?
If so, I guess I should send it back and get the vented one or fix the original?
thanks for your replies

 

[TomMull]

When you find a vented breather cap to fit a TR alloy cover, please post it here. Never seen one for sale.

Never seen one either but never really looked. Quite common on hotrods and other cars of the period. Here's one for a Mini: https://www.minimania.com/part/FP27/Chrome-Oil-Cap-For-Fp26-Flat-Top-Alloy-Valve-Cover-Vented
Doesn't seem too sophisticated, a cap with a hole with some stuffing in it.
Cheers,
Tom

 

[TomMull]

Will the engine vent satisfactorily out of the overboard vent pipe?
Does it require a vent from the top?

Good questions. It's always seemed like overkill to me but most engines of that period had crankcase and valve cover vents. Also strange that yours has no provision for a vent. Didn't the TR4s have a nipple on the side of the cover to vent into the air cleaners or intake? And no lower vent?
Tom

 

[TR3driver]

Interesting. Their database says it fits TR2-4, but the online TR4 "Glove Box Companion" is fairly specific that it is for early TR4. Might be worth pointing that out to them, as I think it is probably a mistake in the data base.
https://trf.zeni.net/TR4-GB/index.php?menu=R&page=23

I don't know how important the top vent is. I've read articles that talk about incoming fresh air (to the crankcase) being important, as it helps flush out any vapors that can otherwise cause varnish and contaminate the oil. But how much of a difference you would actually notice without it, I can't say. However, it should be easy enough to add a vent if you want. You just need to drill an appropriate size hole and fit an aftermarket vent.

Here's a couple that look like they would work well (but please do your own research, I didn't look at them in detail).
https://www.summitracing.com/parts/edl-4405/overview/
https://www.summitracing.com/parts/knn-62-1160/overview/

 

[TR3driver]

Doesn't seem too sophisticated, a cap with a hole with some stuffing in it.

Seems hard to believe that little hole would do anything, on a TR3 with that big breather tube on the side. Even my 3hp lawnmower has a bigger vent than that!

 

[TR3driver]

Good questions. It's always seemed like overkill to me but most engines of that period had crankcase and valve cover vents.

Most cars today still use two ports, one connected to the PCV valve and one connected (usually) to the main intake air filter housing. The line to the air filter housing gets clean, filtered air for the crankcase during normal operation; but also serves as a vent line during full throttle operation (when the PCV valve can't suck out fumes). The connection to the main filter housing ensures that any vapors coming out still get sucked into the engine to be burned.

 

[BillyB62]

A couple of years ago I bought the wrong valve cover for my 3A which had a vent. I had seen (I think on this forum) where someone had installed the KNN vent filter as Randall points to in his post above from Summit Racing. I'm not sure if it does any good, but it looked better than just capping it.