BRM Head Installation help

My PD pump failed when a piece of the key that fits on the camshaft broke off and locked up my camshaft causing the timing belt to shear off the cogs and all four exhaust valves to bend. I replaced the valves. All of the valves guides seem to have the same amount of play and based on the spec, i decided not to replace them. I didnt lap the new valves because the valve seats looked perfect with no pitting (engine has 300k on it) The manual doesn't say how to properly install the head. Should I install the camshaft before I mount the head on the engine? If I mount the head to the block without a cam, obviously the valves are not open. I can rotate the crank to TDC and back off 90 degrees so the pistons are half way to TDC and put the head on and mount the camshaft, align the camshaft to TDC and rotate the crankshaft 90 degrees back to where it originally was at TDC. I just dont want to bend any exhaust valves again. Any help would be much appreciated.

That won't work... at least if I understand what you're proposing to do, because at if the cam is at TDC some valves will be depressed, which will prevent you from rotating the crank back to TDC.

My preferred method is to get the engine to TDC, bolt on the head *without* the cam, and then install the cam at TDC as well. No way anything will interfere that way.

That said, you could install the head/cam as one unit, with the cam locked at TDC. Same difference... I just like to have the head bolted down before I start torquing the cam bolts to the right torque.

Doing it the way Vince suggested will work, but may not actually be completely necessary.

I have just installed a Franko6 camshaft in my TDI. I did so by rotating the crankshaft 90 degrees counterclockwise from TDC, but installing the camshaft with the #1 lobes both pointed forward, installing the cam sprocket then rotating the cam back to the TDC position prior to rotating the crank back clockwise to TDC. My car runs great now, so this method must work. Contact Franko6 and take his advice if you want your car to work correctly.

I did it with the cam already installed. I would email or PM Franko6 for advice. Franko6 is the authority on VW cams and heads. John

Thanks guys, I'll talk with Frank. I was told it is possible to bend the rods when an event like this happens. I plan to buy a deck bridge + gauge to measure the deck clearance. If I see one significantly different from the other, I will know I have a problem.

No doubt many different ways to grease this cat... none more particularly "right" than the other IMHO.

The only real rule: move the crank by hand (rather than using the starter) and STOP AND THINK if you meet with any resistance. Grunting thru an obstacle is how things get bent.

I am running into an issue with the assembly. I installed the head and cam and locked everything at TDC and there is no compression. I am really stumped. My gut tells me I have a camshaft without the proper grind or incorrect lifters. Here is what I did:
1) Measure piston protrusion using a deck bridge -- everything is in spec
2) Bolt head to engine using a 2 hole head gasket
3) Lock crank at TDC, then rotate CCW 90 degrees so all of the pistons are roughly half way up the cylinder
4) Install the cam and lock at TDC so the first lobe is pointing towards the front of the car
5) Lock the crank at TDC. At this point cylinder #1 and #4 should be at TDC.

When I blow air in the glow plug hole of cylinder #1 at TDC with the cam and crank are lock, I can hear air coming out of the EGR tube. A lot of air, not like a whistle. This is a stiff breeze coming out. Initially, I thought I had bent the valves somehow so I removed the camshaft and then proceeded to blow air in each glow plug hole because without the camshaft, all the valves will be closed. The first cylinder I did was #1 and it cranked over the engine a little bit. I removed the hose and a burst of air came out so the valves are sealing. I did this to each cylinder and the all of the valves hold air just fine. If anyone has had a similar experience, I would greatly like to know what the solution is. I bought the AMC camshaft kit part number 666863K and the lifter part number is 668581 (black nitride). My gut feeling is the camshaft grind is not correct, the lifter buckets are too tall, or the valve seats is shot, but the car ran just fine before the exhaust valves collided with the pistons so I find it hard to believe the valve seats are bad or the valves have stretched on such a low revving engine. I also made sure the keepers were installed correctly and the camshaft bearings seemed to be the correct size because they sit snug on the camshaft.

How long after you installed the cam did you blow air into #1?

Where were the lobes for #1 when you ran this test? (need to ensure they were both pointing up)

greengeeker said:

How long after you installed the cam did you blow air into #1?

Where were the lobes for #1 when you ran this test? (need to ensure they were both pointing up)

Click to expand...

I waited > 30 minutes per the manual. For cylinder #1, at TDC the lobes do not point up. One lobe is pointed towards the back of the car, one towards the front. Not sure which is intake/exhaust. The first lobe from the camshaft pulley pointed towards the front of the car, while the second lobe pointed towards the rear.

They both should be pointing more-or-less 45 degrees of "up"... or at the very least not depressing either valve in any way... otherwise there's an issue with the initial timing belt install.

Are you at a point where you can put everything back to TDC and confirm the cam is not trying to depress either valve on #1?

what Vince said.

Vince Waldon said:

They both should be pointing more-or-less 45 degrees of "up"... or at the very least not depressing either valve in any way... otherwise there's an issue with the initial timing belt install.

Are you at a point where you can put everything back to TDC and confirm the cam is not trying to depress either valve on #1?

Click to expand...

Vince,

I originally put the belt on and spun it by had and it there was no binding. Now I have the rockers off and the belt off. The cam lobes are pointing at about 45 degree angles for cylinder number with respect to the plane on the engine. I have a picture, but not sure it will work with the link. If you have a gmail account, you can view it https://photos.app.goo.gl/4s6B5PnXYu5mMyaDA


I would like to add that there appears to be pressure on the lifters at TDC. I believe this is why the intake valves are openings up.

jreich said:

Vince,

I originally put the belt on and spun it by had and it there was no binding. Now I have the rockers off and the belt off. The cam lobes are pointing at about 45 degree angles for cylinder number with respect to the plane on the engine. I have a picture, but not sure it will work with the link. If you have a gmail account, you can view it https://photos.app.goo.gl/4s6B5PnXYu5mMyaDA


I would like to add that there appears to be pressure on the lifters at TDC. I believe this is why the intake valves are openings up.

Click to expand...

in that picture, your cam is at TDC. Is the crank also at TDC?

It is normal for the base circle of the cam to put pressure on the lifter. It should not be opening the valve however.

greengeeker said:

in that picture, your cam is at TDC. Is the crank also at TDC?

It is normal for the base circle of the cam to put pressure on the lifter. It should not be opening the valve however.

Click to expand...

Yes, I have the crank locked at at TDC. I am just really puzzled why the intake valves are partially open at TDC. The OEM cam was replaced at 145k with a BEW cam. The car currently has 280k miles on it. The fact that the valves sealed and held 75 PSI without the cam installed makes me think the seats are fine and the valves are not bent in any way. I am not an expert when it comes to this. I called Frank06 and he said could rebuild the head, but I am not really wanting to spend 2k for a car worth maybe 3k. I am not sure if they made different lifters for the PD engine or variations of cam profiles based on the engine. When I was eye balling the math, you have very little gap between the valves and pistons at TDC. When the valves are seated, they still protrude from the head and when the piston is at TDC, it sticks out of the head. The gap when you are at TDC between the valves and pistons has to be < 1mm I would suspect.

Yup, I'd agree that cam looks like it's at TDC.

If you can blow air out of #1 right now (confirming a valve on #1 is open at this point... and if there's no air with the cam removed... then yes I'd guess there's a wrong part in the valve train... most likely either the valve stem on the valves is too long or the lifters too thick. Could be the wrong cam too, I suppose.

If you've got part numbers of the stuff you ordered maybe post 'em up and see if the hive mind can confirm one why or t'other?

Vince Waldon said:

Yup, I'd agree that cam looks like it's at TDC.

If you can blow air out of #1 right now (confirming a valve on #1 is open at this point... and if there's no air with the cam removed... then yes I'd guess there's a wrong part in the valve train... most likely either the valve stem on the valves is too long or the lifters too thick. Could be the wrong cam too, I suppose.

If you've got part numbers of the stuff you ordered maybe post 'em up and see if the hive mind can confirm one why or t'other?

Click to expand...

Vince,
I didn't replace the intake valves, so I find it heard to believe they are bad. I bought the cam kit from IDParts.com along with the intervalves exhaust valves. The cam is from AMC part number 666863K. I looked it up and it looks like it is meant for BRMs. The lifters are also from AMC and that part number is 668581. They came in a box as a kit. I called IDParts and they don't seem to think the cam kit is wrong, but there are a limited number of variables. 1) wrong cam grind, 2) wrong lifters (or out of spec) 3) valve seats not in spec 4) valves too long. I don't believe I put the intake valves back in the head incorrectly, but even if i did, i don't see how the intake valves could stay open. I double check the valve keepers to make sure they were put in correctly. The car was running just fine before the tandem pump failed causing damage to the exhaust valves. I find it hard to believe the OEM intake valves (which were not replaced) are bad or the valve seats are so bad that there is that much air escaping. After all, without the cam the valves make perfect contact with the head and does not leak into the exhaust or intake ports. I can't easily measure the cam profile since I don't have the equipment. I have a cheap dial gauge caliper.

sptsailing said:

Doing it the way Vince suggested will work, but may not actually be completely necessary.
I have just installed a Franko6 camshaft in my TDI. I did so by rotating the crankshaft 90 degrees counterclockwise from TDC, but installing the camshaft with the #1 lobes both pointed forward, installing the cam sprocket then rotating the cam back to the TDC position prior to rotating the crank back clockwise to TDC. My car runs great now, so this method must work. Contact Franko6 and take his advice if you want your car to work correctly.

Click to expand...

Additional explanation. With the crank 90 degrees counterclockwise from TDC, all of the pistons are half way down their bores and you can turn the cam anywhere you want without risk of damage.
What you do is leave the crank at 90 degrees CCW, install the head, install the camshaft and set the lash for the injectors. Remember at this point, you can still turn the cam anywhere you like without damage.

After the injector lash is adjusted, you turn the cam any direction you like to TDC and pin it and then turn the crank 90 degrees CW and pin it and you are ready to install the T/B. Just like Frank explained it to me......................

So I looked again, and the valves are sitting below the valve keepers. That is definitely the problem. Dumb me Does anyone have a DIY head on valve spring compressor? Do you think I will need compressed air in the cylinder when compressing the valve springs? Even at TDC, the valve would probably drop 1-2 mm?

The top of the piston makes an excellent valve stop that should work to redo the keepers... just be gentle.

Worth a try at least, otherwise yup compressed air.

Well it worked. I bought a valve spring compressor that you bolt to the ends of the head. I was able to fix all the keepers and the car fired up!! The valves probably dropped 1-2mm when resting on the pistons, but the tool worked like a champ (cheap 20 dollar ebay china compressor). Time for a road test. I am slightly worried about the oil pump going through all of the metal shavings from the lifters. Is there an easy way to read the oil pressure?? I bought the mini can OBDII a while back, just never used it.

Oil pressure is not monitored by the ECU... not even the low pressure switch... so it can't report anything via OBD2.

A gauge plumbed in where the low pressure switch goes is really your only option in terms of getting actual readings.

When I replaced my cam due to failure and holing in one of the lifters, Franko6 advised me that the wisest thing to do would be to replace the oil pump as well. This of course requires removing then reinstalling the oil reservoir, which is an inherently undesirable activity, but I took his advice and did so. The old oil pump did show some scoring, but my neighbor, who an expert mechanic for the Coast Guard and their mechanics trainer for the C-130, inspected it and said it did not look bad.

sptsailing said:

When I replaced my cam due to failure and holing in one of the lifters, Franko6 advised me that the wisest thing to do would be to replace the oil pump as well. This of course requires removing then reinstalling the oil reservoir, which is an inherently undesirable activity, but I took his advice and did so. The old oil pump did show some scoring, but my neighbor, who an expert mechanic for the Coast Guard and their mechanics trainer for the C-130, inspected it and said it did not look bad.

Click to expand...

That's good to know. Franko6 mentioned that to me too. This is the 2rd camshaft to go into the car. The first was replaced at around 150k with a BEW febi, now at 280k with an OEM style BRM cam from AMS. When I pulled out the lifters, one was wearing through the metal, the rest just had spider cracks from the valves hitting the pistons. I've put almost 500 miles on the car since the head rebuild, so far so good. The fuel economy from the computer doesn't seem to be as good as before, but I need to calculate the actual MPG instead of looking at the computer. I am getting about 38 MPGs in rainy conditions according to the computer going about 70-75 MPH. I had the timing lined up pretty good so my torsion values are probably pretty close to the spec. As much as I dislike the bentley manual, it has a pretty good description on how to change the timing belt.

Glad to hear you got it up and running and that it was something silly/simple.

"torsion" being off just 2 degrees can have a major impact on FE. Even when I do them using all the tools and whatnot, I'll still find the torsion value quite a bit off and requires adjustment.