Noisy Valves

[Alex6373]

Hi just a question about my non hydraulic valves in my 1973 vw Westfalia
The have gotten loud after i have used several tanks of high octane fuel .
I am wondering if this causes valves to become loud as they were designed to have lead to help them . I am wondering if i should just go back to regular fuel -lower cost - burns cooler ?
The valves have been checked and are around .006 so maybe its just me but they seam louder than before
I am using 10-30 oil and changed it to 20-50 hoping it would help but no .
Any suggestions as to how to quiet them down would be appreciated.
Thx

[timvw7476]

Thanks for the image ! Well, no, no thick oil is going to help.
I'm looking at the bottom of your '73. It had some decent valves & seats when new, & whatever is in there will be immune to lead-free gasoline.
What I'm interested in is your fuel pump. in 1973 that meant a manual one, hanging off the passenger side near the vacuum modulator I see in your image. Is it still there? Is there an electric pump instead? The best way to run a '73 dual carb engine case with an electric pump is too leave the fuel pump push rod in the case, it blocks & meters the oil flow to the right side cylinders #1 & 2.
I'd check to see if that rod is still in the case, it doesn't have to run a pump, just be there as a dowel of sorts....
The other thing is IF you have had no pushrod there, the rocker adjusters on the 1/2 side get mashed quite a bit, deformed & become difficult to just pass a .006" gauge through with consistent 'feel'. Also be ware the exhausts back then had an extra clearance for factory sodium filled exhausts. .008" was the recommended clearance for those. They better be long gone though..
EDIT: also forgot, the way to set valves is at ambient temp,.with a stone-cold engine. This way you can set a 'tight' .006" on everything with confidence. These engines are like balloons, once warm, you really can't set a valve properly. Good Luck with it!

[Wildthings]

The fuel should have nothing to do with the valve lash. Leaded fuel was an engine destroyer, so be glad it is gone. It would build up on the valves and valve seats and then a chunk would break off leaving a gap and a burnt valve would be the result. There were lots of other ways lead harmed engines as well. The weight of the oil should not effect the valve lash either.

One things that happens with valves is that the ends of the valve stems wear to a concave shape, which makes it hard to set the lash correctly using a feeler, gauge. If you have a 0.005" divot on the end of the valve stem and you set the lash with a 0.006" feeler gauge you will end up with a 0.011" lash and have lots of noise as a result. Low quality valve adjusting screws will also wear quickly causing the valve adjustment to be loose.

You can add lash caps or remove the rockers and use a Dremel to flatten the valve stem ends. You can also use math and a protractor to set the adjustment.

[Alex6373]

Wildthings
Thank you for your help understanding the posable cause . The heads were redone a while back however not too many miles since .
I will do a closer inspection regarding both the ends of the valves and more likely the valve adjustment screws - they probably need to be replaced .
Would you have a good reference for a replacement screw that are not junk .
I am located on Vancouver Island Canada so tend to deal with CIP alot . Whether good or bad .
Also had a question about waive washers should i replace these as they might be not keeping the rocker on the valve ?
Anyway thx

[airschooled]

It's easy to misinterpret exhaust leaks as valve noise. Do you have a video or the engine idling, plus a little throttle rev?

Robbie
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[Wildthings]

I have a very low opinion of CIPs. Bus Lab seems to have about the best quality one can find. There are two different sizes of valve adjusting screws used on a Type 4, both an 8mm and a 10mm, so if you find you need them then check to make sure what you actually have.

I will agree that exhaust leaks can mimic valve noises.

[Alex6373]

So after a think !
Decided to have a look under the bus .
I found some loose exhaust studs on the motor .
Decided to pull motor and check a few things .

I rebult the top end a few years back with 96mm A&A piston set , i thought i had purchased a 1800 motor 15 years ago when i dropped a piston on number three.

But these engine numbers are telling me that it was a 1700!.
My problem with this is the 96mm pistons slipped into the case !
I thought you had to get the case opened up for the step from 1700 to 1800?

[Alex6373]

So i increased the cc ‘s by 200 and thought i was just going from 1800 to 1900 and calculated wrong when setting this up !. I am open to suggestions .
The motor ran but was gutless , its a automatic and drives nice but a little more on some hills would be nice .

Also it is hard to start as it seems the timing is jumping around leading me to think that endplay was a factor , but upon inspection so far its very tight . So maybe distributer drive may be worn out?
When starting it sometimes backfires or is hard to start !

[Wildthings]

What do you have your timing set at?

Does your engine have a timing scale?

[Alex6373]

I have found out the problem .

The motor is a 1700 which has been machined out to except 1800 pistons .

When i installed the piston set i measured the deck hight and ….. then i installed

The cylinder head Shims ( finding out now that these are not used ) .

This caused my calculation to be out and have very low compression.

I will do more measurements and make sure i have no vacuum leaks .

I might have new shims (10mm) i think this will bring my compression up!

Thanks for everyone’s help !!!!!

[mikedjames]

If you put the distributor in just right, the drive dog just barely locks in place.

I once tried to help diagnose a T4 engine where the timing would suddenly jump, until we reinstalled the distributor , getting it down , I think the tinware interfered with it.

But that wasnt the only problem, it still barely idled but could rev up off load, but drove badly.

When the engine was finally stripped down, one of the head gasket rings was missing on one cylinder, so there were sealing issues.
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Ancient vehicles and vessels

1974 VW T2 : Devon Eurovette camper with 1641 DP T1 engine, Progressive carb, full flow oil cooler, EDIS crank timed ignition.
Engine 1: 40k miles (rocker shaft clip fell off), Engine 2: 30k miles (rebuild, dropped valve). Engine 3: a JK Preservation Parts "new" engine, aluminium case: 26k miles: new top end.
Gearbox rebuild 2021 by Bears.

1979 Westerly GK24 24 foot racer/cruiser yacht Forethought of Gosport.
1973 wooden Pacer sailing dinghy

[Alex6373]

I think there is a little confusion about what I have asked about .

There cylinder BASE washers to adjust deck hight , seal cylinders

There are in a type four vw 1700 by VW spec
Cylinder TOP Sealing washers .

These as I find out were eliminated by VW service bulletin!!!

Now if you have stock vw heads and cylinders maybe you still need them !!!

I have a set of new A&A 1900 big bore cylinders.

VW bulletin states not to use them , cylinder sealing washers as they lower my compression .

This is why my bus is hard to start …….low compression!

[Wildthings]

[Alex6373]

yes Wild things thanks !!