I second that!

I called him with a bunch of weird "ninja" questions.
These can be hard to answer!
He KICKED ASS!
I will have to hit him up when it comes time to make my choice.
I AM WAITING for SuperHawk too...
I like "The Hawk's" way of doing things!

Ah - the link to the Samba T4 pump rebuild is as in my thread. The author does a great job documenting a T4 pump rebuild.

https://www.thesamba.com/vw/forum/viewtopic.php?t=699156

I have a mill and would use a single point carbide drill capable of easily drilling the case hardened idler shaft so I would pin it a little differently but the method outlined here is perfectly plausible for those with only a drill press.

I didn’t touch on it in my thread but the main problem with larger gears like 30mm is that too much pressure will cause the oil cooler to bypass. This in turn creates overheating.

If running an auxiliary cooler with long hose lengths to the front of the car and back plus restriction of a an external thermostat - the 30mm pump would be fine.

I’m not going to comment too much on the Tangerine relief since I don’t know what pressure he has it set to. It clearly has a place if the engine relief bore is worn and/or if the spring has become weak.

I did a quick measurement of spring rate, distance between the relief passage and closed position and the piston size of my low mileage engine GA000099. I calculated it was something like 80-84 psi needed to bypass the cooler so I’m not worried about my relief valve opening prematurely when engine is warmed. Since that engine is not yet assembled I can’t comment on how accurate my calculation turned out to be. I will say that I wouldn’t hesitate to use the Tangerine relief replacement if I have any signs of unusually low oil pressure.

The bottom line is too much pressure isn’t good for stock cooler longevity and will blow out the seals / leak if pressure is too high. Where that system goes tilt is an unknown and why I’d like to eventually build up a pressure test rig - just for my own learning and verification of T4 pumps.

If running an aux cooler with hard plumbed fittings there would be no oil cooler seals to blow out.

You might look closer at that valve...

I was EXACTLY like you in my original assessment. Needed for damaged stuff!

My T4 core has a FLAWLESS relief valve bore.
The valve itself is perfect...
I was planning on reusing it till I saw the bit regarding changes to flow rate between cold and hot and how hot high pressure could do EXACTLY what you referenced.

One of the differences between the Tangerine valve and stock specifically addressed this issue.

At that point it became "must have at pretty much any price" for me.

The fact that it's less than a hundred bucks makes it easier to swallow.

I'll have to look at one closely when I purchase but that one design difference (if it works like it was described!) could be the WHOLE MOTOR in a worst-case scenario.
The Tangerine valve should have been that way the Germans designed it from the get-go in my book.

TRs getting my money!
At least once...

@vjb206

This is a rod modification you may want to consider.

Just looked through that. Thanks, cgnj!

Rod mods look fine (if you're reusing stockers)
I believe you should either have spray from a rod-based hole or dedicated piston crown sprayers.

Thier suggestions regarding shims/head fire rings should be taken with a grain of salt, especially if you're building a non-stock motor.

I believe you should choose your deck height via measurements during your build.
Just saying use a 1.6mm ring under the barrels is not enough in my book.
You should end up with the perfect spacing via dial indicator and only THEN should you look to what is available.
Choose what is closest, make your own, machine barrels, what every it takes to get close to your chosen deck height.

Deck height varies for different alloys. Forged with low silica will require more bore and deck clearance vs a hypereutectic cast piston.
Look to your piston manufacture for their suggestions.

The original clearance in the TSB (technical service bulletin) are WAY tight in my book.
Original bore to piston is from .00086" to .0015".
This is a "9 tenths" clearance!!!!
Less than a thousands for an air-cooled motor!
Freaking tight!
They had problems accordingly...

Cast I'd expect to be running at least .002" and more likely .0025".
I like tight quench motors and I'd run more that .035 but less than .040 on cast.
Forged would be higher. At least .004" P/C and .045"+ quench.

The rod idea has merit, the suggested deck height changing procedure is not really applicable to a "built" motor in my book.