2 types of oil check valves ?

[A1quattro]

i have 2 iron 20v blocks with 2 different style oil check valves [that restrict oil flow to head ]. one has a long spring the other just a bung with a ballbearing valve . which is the best type or are they both fine

[quattro84]

Pics for reference?

[Billman]

The diesel ones use the long spring type. remember the other one is bolted in the block so they are not interchangeable between blocks of different type.

[michaels2s]

you can use both of them.
important is that they are in good condition.

[Billman]

Not in every block. The ball type is screwed with a torx in the block. the other one not.

[UrS4boy]

20VT (AAN, ABY and ADU) oil check valve info

i have 2 iron 20v blocks with 2 different style oil check valves [that restrict oil flow to head ]. one has a long spring the other just a bung with a ballbearing valve . which is the best type or are they both fine

Ours is the one shown below. Location, etc, and how you can crush it with an ARP main cap stud if you don't pay attention to detail is discussed in this post:

AAN Oil Pressure Sender, Switches, Wiring and Check Valves:

http://forums.quattroworld.com/s4s6/msgs/96161.phtml

[A1quattro]

great responce i have gone for the type fitted with spring ,as its going into the alloy engine block and all the oil ways had to be drilled [new block] , the spring type is smaller in diameter which is better for the alloy block . its stange that apparently spring type was fitted to diesel blocks as both my old blocks were 20v t . are there any casting numbers on block to confirm which block they are, i always beleaved one of the blocks was originaly from a rs2

[JariP]

Late 20vt blocks came with the spring type check valve. I have one very late block bought as a spare part and it has the spring type. No idea when the switch happened, I reckon somewhere around -95 or -96 earliest.

Regarding the check valve types, both of them are actually same kind of ball valves, the big outer spring only holds the valve body in place and there's a ball and another spring inside working as the restrective part.

[A1quattro]

following on from my original post regarding the 2 different types of oil check valves we fitted the spring type , on a new built engine . since day one its been blowing out oil and after removing the valve today and comparing the 2 diff valves closely it seems that the spring type , that we have has much bigger holes in the valve to flow oil to head [poss 3 times bigger ] we now beleave this has been causing far to much oil to flow into the head at high revs , so much so that oil has been blowing out of rear breather on the cam cover . has any one experienced this problem using the spring type check valve . apparently diesel blocks and very late 20vt blocks had these spring type valves

[UrS4boy]

The AEL 2.5L has a "valve", PN 046103175A, that might be the one that you are talking about. I can't find any photos. Any chance that you took some and could post them here?

The symptoms sounds like the problems that Popdemonic was having in Thailand with his UrS6.

[A1quattro]

the spring type has a narrower valve which dosnt scew into the block but is just held in by the spring when the oil pressure sender is fitted , the holes each end are more or less the same size as the screw in type valve but also it has 2 biggish holes which are open when valve moves which lets the oil directly to head .

[AndyP]

The AEL 2.5L has a "valve", PN 046103175A, that might be the one that you are talking about. I can't find any photos. Any chance that you took some and could post them here?

The symptoms sounds like the problems that Popdemonic was having in Thailand with his UrS6.

Photo's here:-

http://www.s2forum.com/forum/showthread.php?t=44641&highlight=valve

[A1quattro]

thanks , maybe the check valve not the problem then if its fitted to r2s , that's probley what block I got it from , could be just oil surge and the fact the oil drain holes from block face to bottom end are a bit smaller on alloy engine blocks ?

[UrS4boy]

thanks , maybe the check valve not the problem then if its fitted to r2s , that's probley what block I got it from , could be just oil surge and the fact the oil drain holes from block face to bottom end are a bit smaller on alloy engine blocks ?

An RS2 does not have an alloy block. It is the same cast iron block as the AAN and ABY.

[newsh]

Yeah but A1quattro's engine has an alloy block..