diferent between 7a and 3b head

[aronmatic2]

do i have to make the holes for water collector?
what is going to hapen if i skip this job?
maybe the head is going to heat up.

[AnLe]

do i have to make the holes for water collector?
what is going to hapen if i skip this job?
maybe the head is going to heat up.

Yes, there is small change of cracking the head, but if cooling is in order and oilcooled turbo is used and the engine is moderate hp I might try to use it as it is. But any heavyduty or high hp engine is planned this is wrong place to save.

[aronmatic2]

Yes, there is small change of cracking the head, but if cooling is in order and oilcooled turbo is used and the engine is moderate hp I might try to use it as it is. But any heavyduty or high hp engine is planned this is wrong place to save.

that is what i think.
i hope, my car going to have more than 400 hp on the wheel.
i make the holes and install the water collector. but is not so easy.

[auditude]

that is what i think.
i hope, my car going to have more than 400 hp on the wheel.
i make the holes and install the water collector. but is not so easy.

I want to do this too with a 7A head I have. I have the head, the water collector, and even a 3B head I can (have used) for a reference.

[audiman]

I heard a rumour that the holes are inside the head already for the water collector on the 7A head, im not sure how true that is, you would have to drill it out to see :O

[RSCoupe]

I want to do this too with a 7A head I have. I have the head, the water collector, and even a 3B head I can (have used) for a reference.

Ken,

Javad's machine shop has a jig for machining the 7A head to accept the turbo water manifold. He quoted me $200 USD each (plus shipping) to have my heads done. I havn't decided if I'm going to do this, or come up with something custom.

[aronmatic2]

we have to make the holes exactly the same place with cnc driller.
its not so easy to locate.

[auditude]

Ken,

Javad's machine shop has a jig for machining the 7A head to accept the turbo water manifold. He quoted me $200 USD each (plus shipping) to have my heads done. I havn't decided if I'm going to do this, or come up with something custom.

Hi,

Yes, and thank you for the reminder. I remember when he first announced it. I couldn't find much about it on motorgeek when I checked last, but I do have the emails somewhere. I want to explore a local solution before having to ship it, but it's nice to know of that option.

I want to find a competent local machine shop to:
modify the 7A head to 3B cooling spec
enlarge the 7A bolt holes to accomodate larger studs/bolts
add oil squirters to an AAF block
modify AAF block to mate with 7A head (passages, etc.)
modify the AAF block to accept the Motronic timing sensors(!)

If possible, I want to use the 7A head with the AAF block, so that I have an untouched 3B long block for something else.

Regarding the CNC difficulty, I have heard that it should be no problem at all if you have the water manifold (collector) or even a turbo head to take measurements off. The reference would be the three studs for the common (2nd on the turbo, somewhat triangle-shaped) hole.

Unfortunately I have no connections in the automotive machine shop world, yet. At this point I don't know who to trust locally for this type of thing. I may very well go with the Javad option since he's running it with success.

Come to think of it, did Marc Swanson end up doing the same conversion to his 20v head? I don't remember if he started with an 7A, but I know he was looking for a water manifold (collector) at one point (now he's got it).

Thanks,

Ken

[audiman]

Christ that a bit of a project for the machine shop. good luck finding someone who can add oil passages to a cast block

[auditude]

Christ that a bit of a project for the machine shop. good luck finding someone who can add oil passages to a cast block

Hmm. My understanding is/was that the passages are there already, and the squirters just go into new holes that need to be made to tap into them. I assume they are the passages that feed oil to the main bearings. While not for this specific block, I have heard of folks adding oil squirters to motors without them.

I also would be surprised if the oil passages were different between the 2.5l gas and 2.5l diesel/tdi blocks, which I understand have the squirters from the factory. But then again, I've been surprised before.

Do you have information to the contrary?

Thanks,

Ken

[audiman]

No i dont have any info, you may be right. Guess there is only one way to find out!! Get the drill out!!

[Audi_CQ]

Hmm. My understanding is/was that the passages are there already, and the squirters just go into new holes that need to be made to tap into them. I assume they are the passages that feed oil to the main bearings. While not for this specific block, I have heard of folks adding oil squirters to motors without them.

I also would be surprised if the oil passages were different between the 2.5l gas and 2.5l diesel/tdi blocks, which I understand have the squirters from the factory. But then again, I've been surprised before.

Do you have information to the contrary?

Thanks,

Ken

No problem Ken, the oil passages are there Here's my modded AAF :

[audiman]

Well thats cool, i guess the old saying is true, "you learn something new everyday".

[audiman]

What is there originally then?? any pics before the machining?

[auditude]

No problem Ken, the oil passages are there Here's my modded AAF :

Thanks! That's a much clearer view than the one I had at the junkyard, pulling the squirters from an MC1 (10vt) there!

I'll print that out and bring it with me to the machine shop. It will be easier to do that than to bring in the 3B (altho' I'll probably bring it in anyway to be sure). I sure need a truck for all this stuff. I brought the 5 speed from the same 10vt car (fwd) home in the trunk of my 200q20v. I guess it wasn't so back tho'. An engine might be different. Or...

One question, what did the machine shop need to put those in? Did you give them some dimensions, or did they figure it out themselves?

Btw, on the non-oil squirter equipped blocks, my understanding is that they have the little flat blank areas just sitting there waiting to be used for them.

Thanks,

Ken