rebuild question

[silver2.0]

I am rebuilding my 1970 914 with a 74 2.0 motor right now. I am in the assembly stage, and I have 4 questions...

1. What type of sealant should I use on the base of the cylinder? I know Mr. Jake Raby had mentioned something before, but I can't for the life of me remember what it was.

2. When rebuilding the heads, I chose to install all new valves, springs, guides, adjustment screws, and keepers. I am having the valve seats 3 angle ground, and he suggested "touching" off the valves with a grinding stone to perfectly aquire my seat. Should I let him grind on my sodium valves, or opt to spend more time with my suction cup and some grinding compound?

3. The previous owner had the temp guage disconnected, can anyone tell me where the sending unit is?

4. What is meant by the term "3 stud head"?

Thanks for your help.

[lapuwali]

The head temp sender is next to cylinder 3, between the spark plug holes. I don't know where the oil temp sender is.

Real 914 2.0 heads (as opposed to Bus heads) have three studs holding down the intake manifold(s) on each side (only one between the ports). The 1.7 and 1.8 heads use four studs, two per port.

[Alfred1]

1. What type of sealant should I use on the base of the cylinder? I know Mr. Jake Raby had mentioned something before, but I can't for the life of me remember what it was.

Check out the post by "bottomend" in this thread http://www.shoptalkforums.com/viewtopic.php?t=61853&postdays=0&postorder=asc&start=15 .

[mikester]

The oil temp sending unit is on the bottom of the engine attached to a round plate commonly refered to as the taco plate. It is inserted into that plate at an angle.

[Dave at Pelican Parts]

1. Use your sealant of choice on the cylinder bases. I don't think it's hugely critical, as long as you get one that stands up to oil.

2. Depends on how much you trust the machinist to take off only what is needed. And also how much you want to avoid the extra valve lapping work.

3. The stock temp gauge is oil temp, as was mentioned. The sender in the head is a CHT sender for the FI system. It will not work with the common aftermarket CHT gauge, as the sender for the latter uses an entirely different principle. (It's a thermocouple instead of an NTC thermistor, if you're into electronics.)

4. Already covered. Note that the VW Bus 2.0 heads were also four-stud heads, so the only three-stud ones were 914/2.0 and 912E.

--DD

[silver2.0]

I have 2 more questions-
1. What are the threaded tubes that go through the sheet metal, and have caps on the end? Are they national pipe thread? Mine became somewhat gualded when they were removed, and I would like to replace them and run a tap down the hole. They look like some way of testing head temps or pressures??

2. What is a reasonable price to pay to have seats replaced? They are 2.0 heads, and both 3 and 4 intakes need to be replaced as they are smashed in really far into the cylinder heads.
I thought the valves were stretching, as I couldn't keep my valves adjusted right, but it must have been the seat. Where can I buy the seats?? Are they still available?? God I hope so.

[mike95125]

Scott, as for the NPT threaded things, do you have a 76 engine? It sounds like the smog pump ends (????)

[Bleyseng]

Sounds like you have the heads with air injection ports. They can be just blocked off or welder shut. If the seats are loose you must rebuild the heads as there is a real trick to install the seats so they don't come out again. Very close tolerances and they are a friction fit. Headflow Masters is the shop to do this or you will be paying to do this again is short order.

Geoff

[silver2.0]

I have no idea what year the heads are. The motor is from a 74 2.0. They are 3 stud heads, with sodium valves, but I am not sure about what year the heads are. They have been off before, because they are stamped, incorrectly I might add, with a firing order, or misorder in this case. Thanks for the advice. My bargin "project" is quickly adding up. I have already bought new springs, valves, keepers, and guides. Just these items alone were over $400. I just have to keep thinking about how fun it is to drive... those were the days....

[Dave at Pelican Parts]

Two heads, several cracks welded up, all new seats, all new exhaust valves, new springs, etc., was about $1300 from one or two places a few years back. Basically "return to stock condition" rebuild of some pretty beat up heads.

I wound up having the same work done locally for $1100 instead, by a shop with almost as good a rep.

From the sound of it, Head Flow Masters can do the same work for less--but it looks like he doesn't usually use the sodium-filled exhaust valves. ($$$!!)

If there are extra holes next to the outer intake studs, then you have 75-76 "smog pump" heads. Those are the air injection ports, and you can plug them with something (I hear Type I valve adjusting lugs work) or have them welded up. Welding obviously is a more permanent solution.

2.0 heads love to crack around the spark plugs, so figure at least a couple of those will need repairing. If the cracks are bad, they'll need to be cut out and welded up and drilled and tapped to spec again. If that's the case, have them drill for smaller plugs to cut down on the stress risers in the heads.

2.0 heads also love to crack on the short radius of the exhaust port. Those usually have to be cut out and welded up again.

If you have dropped several seats, chances are the heads were very significantly overheated. At a minimum, have all the seats done. Chances are pretty decent that some of the above cracks are there, as heat helps them start and spread.

Get the opinion of a good experienced machinist. One with experience with aluminum heads, definitely. One with VW experience, probably. One with 914 experience would be by far preferred.

--DD

[silver2.0]

Thanks for your valuable advice Dave, my heart sank when I saw $1300 dollars though. My wife will leave me before the car is done at this rate!

[Bleyseng]

Sounds like the PO got the engine real hot not having the temp gauge hooked up didn't help. Figure out the "Why". Was it really dirty with grime blocking the air cooling passages? Missing tin? Blocked oil cooler.
Or was it running really lean? If still Djet check all the FI parts to make sure they are all the proper ones for your year.
Just rebuilding and not figuring out the "Why" will bring you back around to the same question.

Geoff

[Jason Porter]

Where are you at Silver 2.0?

[silver2.0]

I am from spokane, wasington, and I know the reason it got hot. The PO did an engine swap, and didn't even bother pulling the tin off when he did this. The engine was PACKED full of leaves, and they were even all around the oil cooler, and in the fins. The cylinders still have their hone marks, and it ran really good, so I am lucky I guess that the valve went instead of a rod or something. I am doing a rebuild to be on the safe side, although I am keeping the old pistons and cylinders. Just replacing the rings. There is virtually no wear on the cylinder walls, and no lip at all. A new hone job and a set of rings, and the top end will be good to go.

[Jason Porter]

What is it about Washington state and teeners full of leaves and pine needles...hmmm

[silver2.0]

I bought it from California!!! By the way, I was just going to order my rings, and I measured my bores to confirm the size, and they measure 96 mm. Is that a bad thing? What does that make the displacement?

[Dave at Pelican Parts]

With the 2.0's 71mm crank, it makes a 2065cc engine.

--DD