dual relief case vw t1

[Zac Reish]

ok I know this is going to rank up there with one of the dumbest questions of all time, but how can you tell if you have a dual relief case. what is the advantage of this and the reason I ask is because i recently acqured a motor that may not be dual relief. Should this case be scrapped. I have heard they are not worth building high performance motors.

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[mightyjeep]

The only dumb question is the one not asked!

I am new to the 1600 class, so I dont know either. I think it is a great question. We all have those ?'s that we dont want to ask, but want the answer.

Brian

[DailyPedal]

Look at the bottom of the case, there are nickel-sized caps with a flat screwdriver slot facing toward the ground. If there is only one, it is single relief, two is dual relief. One plug is toward the front of the motor near the oil pump and the other is back by the rear main-flywheel. You can also do an internet search on the case number 71 and newer is dual relief. If it has 8mm cylinder studs, it is more than likely a dual relief. This is not failsafe as some cases have been rebuilt by VW back in the day and may not have factory serial numbers, or sometimes people install a variety of aftermarket gizmos that may confuse you...if you still are not sure, take some pics and someone will help...

[Co-Dog]

ok I know this is going to rank up there with one of the dumbest questions of all time, but how can you tell if you have a dual relief case. what is the advantage of this and the reason I ask is because i recently acqured a motor that may not be dual relief. Should this case be scrapped. I have heard they are not worth building high performance motors.

Next to the oil pump on the bottom of the case, you will see a something that looks like the top of a giant machine screw that you would need an equally giant flat blade screw driver to remove. There should be another one just like it on the other end of the case. If you have 2, it is dual relief. If you have one, it is not.

If I remember right (its been a long time since I've dealt with VW's), the one in the front relieves pressure between the crank and the oil pump and the one by the flywheel relieves pressure between the crank and the oil cooler.

When the oil is thick during a cold morning start, without the pressure relief you could blow out the aluminum plugs that seal the oil journals in the case. The second relief protects the stock cooler and seals.

Or at least something like that.

[partybarge_pilot]

The second relief protects the stock cooler and seals.

Or at least something like that.

Almost, the second one allows oil to bypass the cooler when cold. When it warms up and pressure drops, it lets the oil through the cooler.

[Zac Reish]

Thank you to everyone who replied. It does have 10mm studs indicating that it may be older. Near the oil pump there is the one relief with the large flat head slot. In the back where the second relief should be there is a hole. the hole does not go straight through it stops. Could i be missing the other relief screw? Also if this is in fact single relief, should I shy away from using the case for a rebuild or will it be fine?

[DailyPedal]

There is more to it than the size of the studs. How big of a motor do you plan to build? What is the bore (bearings) of the case? I would rather build a 10mm case with a standard bore than a 40-over 8mm case. Also look at how much money you want to spend.

[Zac Reish]

i haven't split the case yet. I would like to build (since the case and the heads are cut for 94's) a low compression 2275 so I don't have to spend a grip on race gas. Is this realistic? But again I have always heard steer away from the single reliefs, but what would happen if i did build a big motor with a single relief case? i have never heard from personal experience.

[07FJRog]

i haven't split the case yet. I would like to build (since the case and the heads are cut for 94's) a low compression 2275 so I don't have to spend a grip on race gas. Is this realistic? But again I have always heard steer away from the single reliefs, but what would happen if i did build a big motor with a single relief case? i have never heard from personal experience.

yes, that will be a good combo. I run a 2276 Dual relief at 9:1, on premium gas.

I also run a remote oil cooler with fan and a remote oil filter setup.

now if I could save enough $$ for EFI and get rid of the webers, it would be even better

[DailyPedal]

Have the case checked out really well. You say that the case has already been opened up. Then it was already built into a big bore, probably for 92s, not 94s. My guess is that the case has already been align-bored and will need to be done again...making for a less reliable motor in the end. Big strokers put a lot of stress on cases and a weak cases can collapse, lose oil pressure and take out a stroker crank and rods...all money down the drain.