BEW, BRM, and ALH head gaskets

I dont have any handy, nor do I have any bentleys nearby. What are the primary differences between gaskets for each motor? is there any interchangability?

BEW and BRM should be interchangeable. ALH is most assuredly different! Using 2-hole gaskets as an example:

ALH 1.63mm
BEW 1.57mm (Same part number as BRM)
BRM 1.57mm

Cheers and good night!
-BB

But I'm wondering if the specs are strictly for thickness or if they have to do with ability to seal?

I'm wondering the same thing... Mine refuses to seal... It'll seal with a new gasket for a few weeks, that's about it..

Now that's a question I'm not sure on. Conjecture states that if BEW and BRM have the same part number then it's all the same. They are very similar engines, yeah water pump and cam are different, but the many other parts are the same. I also know you can slap a BEW head on a Passat BHW block. I wouldn't be surprised if a BEW head would work on a BRM. Anyone else have any input?

HMMM. You mean I am ahead of the crowd here?




That is an ALH with a BRM gasket on it. Differences are as follows:

1) thickness of gaskets in comparison with holes
2) Diameter of piston cutout ALH max is around 81mm I am showing a BRM with a 81.75mm piston in the hole.... IIRC 82.0mm would be really tight


Next to address sealing issues...

1) are you using arp head stud bolts? (old version I will not comment on the new ones until I use them)
2) Has the head and block been checked for warping? if it is warped that may be your problem
3) I am assuming you are getting leaking from Cyl 2-3 into the coolant bottle? This is very common and suggests to me that your cyl pressures are to high and you would benifit from a CR reduction... What boost are you running above 26psi substained?

shortysclimbin said:

Next to address sealing issues...

1) are you using arp head stud bolts? (old version I will not comment on the new ones until I use them)
2) Has the head and block been checked for warping? if it is warped that may be your problem
3) I am assuming you are getting leaking from Cyl 2-3 into the coolant bottle? This is very common and suggests to me that your cyl pressures are to high and you would benifit from a CR reduction... What boost are you running above 26psi substained?

Click to expand...

1) I have the old ARP's, which worked fine until RC5.. I have a set of the new ones, just need to get a new gasket before I pull it apart.. Stock bolts are a lost cause..

2) The head was perfect when I put it on last time, I have to check it when I pull it apart again.. I need to check the block again too.. It was good last time..

3) Last time it was all 4 that were leaking.. Enough to blow up my heater core, my coolant pressure cap was bad so the heater core gave out first.. Now with a good cap, I can empty the bottle with 2 runs from 0-100.. Sitting idle I get a steady stream of bubbles from the bleed line on top of the bottle.. Also about 3 seconds of full throttle I lose heat momentarily..

I'm running 28-30psi sustained and enough fuel to also sustain 1600EGT as long as I keep the pedal down.. I think I will definitely benefit from reduced CR... I'm waiting for a set of pistons to come back now...

I'm not sure that the PD gaskets are much better besides some small fitting advantages. I have all of them and catalogged the differences a long time ago. SO far, I see no reason to use the PD over the ALH unless the fitting warrants it. I am not sure that the sealing will be of more benefit, though the ones I have are a slightly different material than ALH.

Lower cr will likely help a lot.

ALH
1 hole 1.55mm 038103383al for 0.91 to 1.00 mm piston projection
2 hole 1.63mm 038103383am for 1.01 to 1.10 mm piston projection
3 hole 1.71mm 038103383an for 1.11 to 1.20 mm piston projection

BEW
1 hole 1.49mm 038103383de
2 hole 1.57mm 038103383df
3 hole 1.65mm 038103383dg

BRM
1 hole 1.49mm 038103383de for 0.91 to 1.00 mm piston projection
2 hole 1.57mm 038103383df for 1.01 to 1.10 mm piston projection
3 hole 1.65mm 038103383dg for 1.11 to 1.20 mm piston projection

BHW
1 hole 1.45mm 038103383cp
2 hole 1.53mm 038103383cq
3 hole 1.61mm 038103383cr




I'm currently running a 1 hole, compression reduced by about 1 full point as measured when assembling motor. Peak sustained boost 26lbs. old style ARPs....
I'm pressurizing coolant only on WOT runs. I can tool around town for weeks and not loose any. Both block and head have 6k miles on them after fresh rebuilt, machine shop verified flat.

I'm thinking I'm going to switch to a BEW 2 hole, new bolts, and give it a go.

oldpoopie said:

I'm thinking I'm going to switch to a BEW 2 hole, new bolts, and give it a go.

Click to expand...

Are you thinking the 0.02mm difference is going to drop your PCP enough that you don't have problems or are there other reasons for your switch?

My piston protrusion is currently .75mm, so lower than spec for a 1 hole. I dont want to specifically drop compression any more, but I figured an experement is in order.

Few things noticed about gaskets. AHU/AFN Elring is crap. Not good for even stock power. Reiz holds up with 2.5bar of boost and regular 12.9 bolts. In few IDIs it holds up with past 3bar.

With ALH style gaskets the difference isn't that big. I had 3 hole Elring and it held just fine with 2.4bar for a while. But PCPs were in whole different league compared to usual Jeff+17/22 combo. Nearly 300hp but only 480nm.

Ok, got a ALH and BEW side by side to compare.... Any thoughts on this?
It will bolt right up, but it looks like some of the oil/coolant passages are restricted differently in the BEW gasket vs ALH.
BEW on the left, ALH on the right.

I'm still planning on putting this bew 1 hole gasket in, but pending hernia surgery is likely to put it off a month or so. I was really inspecting the gaskets tonight and noticed something.
The ALH 2 hole gasket is made up of 3 layers, two outer thin ones and one thick center one.
The BEW 1 hole gasket is made up of 5 thin layers.

What do the holes refer to? I am running 26 psi of boost in my BEW with no HG problems. Should I expect it?

The holes refer to the thickness of the headgasket. Its on the edge of the gasket, visable from the front of the motor.

If you are not leaking, I'd not worry unless you really really really push it. Though for insurance you could hope ARP makes a kit to fit the pd, or order a set of ARL head bolts from boraparts.com

Any outcome to this? I've got an ALH at the top end of the 1 hole spec and no-one in town has 1 hole gaskets... I have BEW gaskets and could get a 2 hole ALH gasket.

If it were mine, I would use a 2 hole ALH gasket if it's right at the end of the 1 hole spec.. Looks like the 2 hole BEW is ever so slightly thicker than the 1 hole ALH so that might be an option too.. The coolant passage differences aren't too big of a deal.. Looks like they restrict it a bit by the back of the #4 cylinder.. I've seen different ways of messing around with coolant restriction to even out cylinder temperature..

That's the problem, its not my car, I'd definitely run the BEW gasket if it was mine. I re-measured and its a solid .036 which is definitely a 1 hole.

Ya .036 is at the low end of the 1 hole, so you'll have plenty of clearance.. I'm not sure if I've ever had any with that little protrusion.. Most of the ones I've had at the edge have been right on the edge of 1 and 2 hole..

Depends on how I measure it. I tried multiple points on the piston and when you rock the piston it changes, that is the average. When I use the parallel on the block method(set a ground parallel on the block set the gauge on it and zero it, then go up and down. that measures .037-.038

The place to measure is inline with the wristpin.. that eliminates the differences from rocking the piston.. A different method is to measure in 5 or 6 spots without moving the piston at all, then using the average of all the measurements..

dieselpower04 said:

What do the holes refer to? I am running 26 psi of boost in my BEW with no HG problems. Should I expect it?

Click to expand...

oldpoopie said:

Though for insurance you could order a set of ARL head bolts

Click to expand...

So if i got ARL head bolts, can i swap the head bolts 1 by 1, and if so, which order, or do i need to swap them by removing all BEW bolts then install all ARL bolts?

Evil-Diesel said:

So if i got ARL head bolts, can i swap the head bolts 1 by 1, and if so, which order, or do i need to swap them by removing all BEW bolts then install all ARL bolts?

Click to expand...

On a PD if it hasnt caused an issue I'd leave it alone.

JFettig said:

Depends on how I measure it. I tried multiple points on the piston and when you rock the piston it changes, that is the average. When I use the parallel on the block method(set a ground parallel on the block set the gauge on it and zero it, then go up and down. that measures .037-.038

Click to expand...

I fought this for a while with my rebuild (other end of the range though). Definately measure inline with the wristpin. It's a bit difficult but what i did was to measure each piston at both 3:00 and 9:00 write the measurements down, rotate the motor a full rev and repeat until you get three measurements within 0.001". One other thing was to make sure you always rotate the engine the same way and if you overshoot it go way back and try it again from the same direction. I like a nice tight piston to head clearance to minimize suish volume so if your measurements show a one hole that would be my choice. I'll take a look at the shop tomorrow as i might have a one hole (I think I had all sizes on hand at one point).

Thanks FUB.

I got a gasket already ordered. Its funny, I can overnight a head gasket, crank seal, crank bolt, and a lower roller stud from ID cheaper than I can buy a head gasket at a dealer.

Wrong

JUST LOOKED IN MY 2002 BENTLY HERE IS A PIC FOR WHAT IS LISTED FOR TDI alh SEE PIC NOW I AM ABOUT FED UP WITH TRYING TO FIND THE CORRECT GASKET

oldpoopie said:

ALH
1 hole 1.55mm 038103383al for 0.91 to 1.00 mm piston projection
2 hole 1.63mm 038103383am for 1.01 to 1.10 mm piston projection
3 hole 1.71mm 038103383an for 1.11 to 1.20 mm piston projection

BEW
1 hole 1.49mm 038103383de
2 hole 1.57mm 038103383df
3 hole 1.65mm 038103383dg

BRM
1 hole 1.49mm 038103383de for 0.91 to 1.00 mm piston projection
2 hole 1.57mm 038103383df for 1.01 to 1.10 mm piston projection
3 hole 1.65mm 038103383dg for 1.11 to 1.20 mm piston projection

BHW
1 hole 1.45mm 038103383cp
2 hole 1.53mm 038103383cq
3 hole 1.61mm 038103383cr




I'm currently running a 1 hole, compression reduced by about 1 full point as measured when assembling motor. Peak sustained boost 26lbs. old style ARPs....
I'm pressurizing coolant only on WOT runs. I can tool around town for weeks and not loose any. Both block and head have 6k miles on them after fresh rebuilt, machine shop verified flat.

I'm thinking I'm going to switch to a BEW 2 hole, new bolts, and give it a go.

Click to expand...

That's a definite misprint... The measurements in the picture are for a BHW..

I gave my copy of the mk4 Bently book away because of some pretty bad wiring diagram errors that cost me 6 hours of my time trying to diagnose a simple problem.. I usually find everything I need as far as wiring diagrams on Alldata or Identifix..

Anyone ever figure out why the different gaskets are the way they are?

Looks to my eye that the water ports are the only difference, and they've got similar area, just in different spots. The PDs run a tenth of a millimeter closer piston/head clearance; 0.51mm compared to 0.41mm, no idea why. Also from the information up there it's made up of similar thickness layers rather than the three different thickness layers of the ALH gasket (thick flat plate, very thin shim for which "hole number" it is, and two spring shims for sealing)

Makes me think the PD's got some better sealing properties going on, figuring they're all the same stamping stacked up 4 to the one hole, 5 to the two hole, 6 to the three hole, so the belleville washer made by the creases around the cylinders are all nested and therefore adding their spring rate together.

Got an ALH going together with 1.14mm protrusion, and that makes a PD 3 hole gasket perfect for the ALH figure of piston/head clearance. I'm thinking I'll go with the PD gasket this time, unless someone says that's a bad idea.

Go for it! I have rebuilt a few ALH engines and i always fit the 3 hole gasket and head bolts from ARL engine. Every car is in differet stage o tune and performs flawlesly!