vw engine single relief and dual relief cases oil passages and modifications

[@Mikefngarage]

I realize I pointed to the wrong area on the return on the engine on the full flow system. I dont usually open that up myself I have the machine shop do it or buy the case already done.

[@vintagespeedshop]

You kind of got it right. The rear oil pressure relief valve (pump end ) is solely to control pressure to the oil cooler. When the oil is cold and oil pressure is high it bypasses the cooler to the main gallery, which also allows the oil to get up to operating temperature quicker. The front pressure relief valve (flywheel end) controls the overall main gallery pressure. On a single relief there is no control over the main gallery pressure so they used to blow oil cooler seals in very cold climates.

[@VWJawbreaker]

Single relief cases still work well for stock engines and mild performance engines as long as you don’t expect 9 billion rpms out of it. Also, doesn’t matter what case you’re using, the higher rpm you push your engine the shorter it’s life expectancies.

[@Mikefngarage]

for me it is just what am I investing to put in the case. Like stroker crank or ibeam rods expensive cam. Yea for stock parts it is fine. Low rpm great for that. someone could use a stock crank small cam and stock ported heads and do just fine. or put top end parts that can be transferred to more bottom end later

[@JWClassicVW]

Some great information, love hearing any and all historic information about VW.

[@Mikefngarage]

thanks for the comment.

[@felixlafuente9714]

The first relief controls oil temperature passing / surpassing oil cooler, feeding main gallery front to back when coldest and back to front at normal oil temperatures; and the second relief valve controls overall pressure of the sistem.

[@alistairclyne9362]

Hi Mike, thanks for this video. I'm now relieved to learn that my 1776 has got a dual relief case! However, I've got excessive end float so I'm in the process of stripping it. Just hope it can be saved .... anyway, thanks for such a clearly explained video!! :)

[@gilbertnowak5770]

The reason VW went with the Dual -Relief case is because in cold weather climates they had a problem with the oil being cold, the oil would become thick. When the engine starts with thick oil the presure would rise very fast causing the o-rings in the oil cooler to rupture. To eliminate this problem Vw desided on some 1500 and All 1600 cases to go with the dual- relief redesigned case. At the same time they changed over the the Aluminum oil cooler.

[@Mikefngarage]

yea I dont know if I would put a dog house on one. We may do another budget build with the one I have. I wouldnt want to invest machine work money in a single relief. maybe a line bore but not much more than that.

[@gazzafloss]

There is a point where increasing lube system pressure only leads to excess power drain on the engine and excess wear on the oil pump/pump drive. It's why modern engines run oils down to zero weight (0w-30w), admittedly running clearance are finer than older engines. Quality lubricants and we'll spec'd clearances are the engines friend.

[@JWClassicVW]

Good info Gary!!

[@Mikefngarage]

makes me think about something.... what about using synthetic oil in a single relief. might be a good experiment. thinner oil will move through the passages with less resistance. Might be up for that one.

[@gazzafloss]

@@Mikefngarage Yes Mike, a friend of mine here in Australia is into historic racing MG's, he's had problems wearing out the camshaft and oil pump "skew" drive gears because he had a high capacity oil pump He's reduced the oil pump capacity, now using full synth low weight oils with an accumulator charge system for cold starts, more delivered HP and no further problems with oil pump drives and relief valves. He said evidence showed that the large pump was loading the system up and running the relief valve full open and wearing the pump and drive gears.

[@FeveredMind]

Thanks for sharing. I am starting to learn about possibly building my own engine.

[@djambrosia]

The hoover mods were done to mitigate wear caused by running the engines at a constant high rpm in a plane. He was really pushing the limitations of the stock oiling system. In my opinion this mod is only really required for engines that are run really really hard, but it's an excellent upgrade that definitely works. One issue I always have in WBX and T4 engines is that the oil pump is a loose fit in the case requiring them to be o-ringed. Do T1 engines have the same issues with Schadek pumps?

[@Mikefngarage]

makes sense to me too. relieving some of the work from the center main could not hurt anything IMO. supply from the front cam bearing would be easily resupplied because it is really close to the pump.

[@JWClassicVW]

Never seen the use of an O-ring with the oil pump, that is very interesting. I never worked on a T4 engine.

[@djambrosia]

@@JWClassicVW The pump body is so loose in the case you can just pull it out by hand and wiggle it about. I o-ring each side of the inlet/outlet holes to prevent air cavitation and oil bleed off when hot. Gene Berg offers o-ringed pumps your side of the pond. Gives a 30% pressure improvement at hot idle. I think it's only an issue with WBX and T4 cases. You can also machine the front groove for an o-ring but you need to clearance the gears correctly as there is no gasket fitted.

[@Mikefngarage]

some of the early aluminum castings or machine work on the t1 aluminum case had issues with needing an o'ring added to the pump. and if the pump housing wore out it was also a fix. cant remember why that happened.

[@KoenigsTiger957]

Thank you for the great video!!!

[@Mikefngarage]

thanks for watching

[@JWClassicVW]

Yes another great Video Mike!

[@FixinBugsNStuff]

Nice video, I had to share in my description.

[@glotube1028]

Very cool mike, thanks, good job explaining it.

[@jacquelinechellis4036]

The small main oil galley is not going to suffer from low oil pressure due to its size but low volume especially to what it feeds. Higher pressure can push more oil to places harder to reach but also cause greater volume bleed off in areas that are loose like worn non cam bearing case. If oil pressure drops when engine warms up to a low level at idle but goes up as rpms increase it is close to good adjustment. If oil pressure stays high after motor is hot even at idle that would probably be too high of an adjustment. 10 lbs per 1000 is a good goal so as not to over pressurize the seals and cooler.

[@gabe5946]

Good explanation of how it works/ thanks

[@jimmywilkinson9190]

It seems like on a dual relief the front one by the flywheel, opens when it warms up. On mine you can hear it open up. Somewhere in a box I have a G.B. ball valve pump. It is used but they used a real VW pump to build it. I can not remember if it is a large hole or small.

[@Mikefngarage]

yea your right on that part of it I was a bit confused.

[@Mikefngarage]

I believe that spring has 2 actions. one pressure 2 heat and it releases the tension by one or the other so the oil cooler gets oil after warm up. FIrst bearings then cooler.

[@fakhroo5]

Love this. Thank u.

[@charlesgraham9954]

one of my pet peeves is someone that understood what u said but had to correct u on his way of saying a word, i don't keep people around me like that. I'll pronounce tomato how i want to.

[@redshirt-scotty]

that flow diagram you have at 3:50 i have found and scrutinized on thesamba and reference it in one of my own vids. are you the guy who posted that stuff?

[@Mikefngarage]

no I just used it for reference.

[@Friedfroglegs]

Thanks

[@OwhyeeVdub]

Oil passage should be a universal phrase. Hahaha😅

[@charlestait5303]

You must have lower pressure on one side of the cooler or you’ll have no flow!

[@amazeddude1780]

A galley is a nautical kitchen.

[@rickgaribaldi1474]

Quit repeating yourself and review what your going to say instead of ooh and ah and uh and you can try this or that stack to the facts and repeating yourself your boring

[@Mikefngarage]

maybe you should try making videos. Dont see any on your user name. then you might understand how hard it is.

[@robotbroken]

@@Mikefngarage - I felt like I gained a good understanding of dual relief oiling systems from this video, I didn't mind that anything was repeated. It just helped to reinforce certain points. I'm new to this channel, but have been around Volkswagen T1's for many years, but am beginning to take on more of my own maintenance and up-keep.Thank you for being so thorough!