Rebuilding 2.0L heads - Page 2

Mark Henry · 11-25-2002, 08:43 PM

Hey Todd

I got a fair bit of time on the engines, it's the winter (almost) up here and all nice cars are now in storage and the projects are underway. For the most part I have at least a couple of months.

This will be my third 911 'assembly job'.
Each time all of the machining has already been done. The first one I ever did was in the early 90's, for a chap that started one and then chickened out and got me to put it togeter. I can't remember if it was a 2 or a 2.2L. The second was for a auto painter, it was a 2.4L out of a '73. He had waited 3 years for some alcoholic German mechanic to put his engine back together. He was so happy to get his 911 back, that he did a primo base/clear body and paint job on one of my bugs. Again this one is suppost to have all the machining done , I just have to put it together. He's suppost to bring it over next weekend.

With these engines once you get over the 'Oh my god, its a 911!!" factor, they are remarkably simiular to the VW engines. Yes the cams are intimadating, but not too bad, you just take your time. Oh yeh, I needed the factory (sucked, but required) and a Haynes manual to figure it out. One day, I would like to do one of the bigger (later) sixes. (maybe for my 914, Hmmm, I wish)

One interesting fact is the intermediate shaft (sits the same as a cam on a T1 & 4, drives the cam chains) uses bug cam bearings, with the two copper coated double thrusts. These are the ones that Gene Berg sold for big bucks! (sorry but they are NLA with the copper coating, damn.) Totally the same, but they were short two small bearing halfs.

It will be a little while before I get to the 914 heads, but I will let you know how I make out. I have 8 heads, plus a couple of bus heads layed out on my bench in a row, looks too cool!

Mark

Jake Raby · 11-26-2002, 08:07 AM

Instaling a seat with .030 of interferance fit will crack the exhaust port so bad its not even funny, I would like to see him do it!!

I use .012-.013 interferance fit, but the key is to use seat material that is above and beyod the factory standard. Even @ .012 they are still tight as hell, and can crack an exhaust port if you are not careful on a 2.0 914 head, they are a weak area..

I don't even sell heads,(pain in the ass and can't make a dime on them!) but I'll tell ya that it is not a game to be played with. In most of my engines, the heads cost me more than all the shortblock parts put together....

Play with heads, and you lose big time, valve failures destroy more parts than all other failures combined, trust me.

Dave at Pelican Parts · Dave at Pelican Parts's Garage

Quote:

Originally posted by hardflex
Can you cut down the chevy titanium valves to whatever size you want?

PD

Uhhh, well it can be done. But I hear that Ti is a real b*tch to machine. As well as loving to gall on anything....

--DD

Jake Raby · 11-26-2002, 01:23 PM

TI Valves like RPM but TI is a strong, but soft material that will last about 1K miles on the street........been there and done that and spent 900 bucks on 8 valves!

todd914 · 11-26-2002, 02:31 PM

Jake, pay for the ticket down here and I'll show you how to make a seat press at .030 without cracking the exhaust port.The trick is to learn from people who have been doing heads and machine work longer than you've been alive. I am only offering my help and not putting others down who are trying to help another person with the experiences I have had. Some of us dont yet know everything and need other's help.

JWest · 11-26-2002, 02:52 PM

Uh Oh. Now Jake is going to have a hissy fit!

Jake Raby · 11-26-2002, 03:03 PM

Nope, no fit at all.........mine don't drop at .012, if they can do it more power to them...

as for age...I selll engines to people weekly that have been working on cars longer than I have been alive..They find me.

The day you stop learning is the day that you think you know everything, no one ever will....

Thats why I call my shop "Aircooled Technology" this is the 21st century of aircooled engine configuration/building and results.

todd914 · 11-26-2002, 03:13 PM

They also sell diapers to people that have been rebuilding motors longer than we've been alive.That doesnt mean much. Try this link for tit valves:
http://www.manleyperformance.com/vw-custom-valves.html

JWest · 11-26-2002, 03:17 PM

So Todd, do you rebuild heads for people?

Jake Raby · 11-26-2002, 04:02 PM

Todd thats exactly right.........

I like your signature line, it says it all.

todd914 · 11-26-2002, 07:03 PM

Yes I do James. I am an ASE certified Toyota tech in San Antonio. I've been doing this since I was 19. I also have worked at a friend's vw Machine shop here in town for the past 3 years on the side. Been doing Vw's since I was 15. Gotta love them aircooled...Jake, I like your motors; they speak for themselves!! Did you find that link helpful? I wonder why you have had such bad experiences with the tit valves. Every single person I know that have used them have been thrilled and hasnt had a problem with them. They use them in drag motors all the time but those arent really the pinnacle on longevity. Usually a rebuild per run.

Jake Raby · 11-26-2002, 07:09 PM

This was a drag race/street engine.....They are okay for engines that don't stay together for long and see really high revs, but for a street car they suck.

todd914 · 11-26-2002, 07:12 PM

Jake, what would you say is the best bang for your buck as far as valves go? Which have you found hold up the best? Which should one stay away from in your opinion?

Mark Henry · 11-26-2002, 07:22 PM

OK guys, were all here to learn.

I'm going to try several different press fits on scrap bus heads before I decide what I like best.

Manley valves are the good ol' boys, but I know Jake likes the SI valves (we're talking stainless now).
So who makes the best seats? Or can i make my own out of Cr-Mo ? 4340? Then flame harden?

FYI the reason I don't just send the heads to a US shop, is that the price for us poor Canadians, by the time we get it back, is almost triple what you would pay. Parts are about double.
So I have more than a few people hoping that I can pull this off.

Oh, does spell check work on this BBS? I can't get it to work, and I only have a few minutes most of the time, so sorry for the mistakes.

Mark

JWest · 11-27-2002, 06:34 AM

Quote:

OK guys, were all here to learn

Yes, that is what I was getting at with my rude little comment. It seems that some people like to pat themselves on the back and slam everyone else instead of just giving their opinion.

I am going out into dangerous waters here, but what annoys me about Jake is that he implys that eveyone else is lazy, sloppy, stupid and can't do heads right and he is the only one that knows how. BUT, he won't sell you heads. Also, if you want a REALLY nice motor, well, he only does one of those a year so he can't build it for you.

How is this helpful? All it does is frustrate us. The way Jake talks about the T4 would make you believe it is only good as a boat anchor unless all sorts of "magic" is performed on it so it will actually last more than 5 minutes.

From what I have seen on the web I do believe that Jake builds good engines and runs a reputable business, but I am often put off by the way he "offers" his advice.

OK, enough of that. This is only my opinion and all of you are welcome to disagree (including Jake!).

DDS · 07:35 AM

Hey Mark:

I went bonkers trying to find shops in the GTA to do my badly mangled 2.0 heads, first a bad one, then a decent one (Rob at Port Perry machine) then a great one (Leitner and Bush in Richmond Hill. Rob is a whiz at welding alloy and such and his prices are reasonable but he isn't tooled up for aircooled. Leitner was recommended by my cousin (Eng. chief of Subaru Cda works rally team, ex FF racer among other things). Bill Junior at Leitner is an aircooled enthusiast of sorts and was fixtured up to flycut and deck my heads. Seat crush was higher than specified, FWIW I have an article that I think was written by/with Mark Stephens performance that describes the process if you want a copy.
Are you the guy doing an engine for Mike Galloway? My flared yellow 914 is in his shop.

FYI I used 44 and 40 mm SS valves, single hd springs, had mangled exh stud repair and several cracks welded. First shop cracked head when installing exhaust valve seat. New seats, new guides, ported, flycut (50cc +.045" deck ht CC and bottom fin decked to clear top find on cyls. HD rocker studs from FAT, 911 adjusters.

I for one am extremely grateful for lots of good advice on setup on this BBS and especially from Jake - he's been a huge help to me, even though I haven't given him a cent - IMHO that's pretty generous for a guy whose knowledge is his stock and trade. I welcome divergent opinions and regard debate as instructive and illuminating, whether I agree or not.

gint · 11-27-2002, 07:32 AM

As long as we're on the subject...

What exactly does the term "flycut" mean in realtion to aircooled heads?

To quote JP, "Pictures would be gud."

Dave at Pelican Parts · Dave at Pelican Parts's Garage

Ain't got pics for you, but all it means is taking some material off of the area that the tops of the cylinders seal to. And possibly a bit more of the chamber to avoid having a "step". (Unless you're specifically trying to put a step in there.)

--DD

Jake Raby · 11-27-2002, 08:28 AM

James, if you don't like it, don't read it. I'm not here to make people think any of this is easy... Sory if I present myself as a jerk, many guys here know me and know I'm not a jerk, but I'm really into what I do and I don't care to share it with people, is that wrong?

There is a certain amount of magic, and non standard procedures required to keep these engines alive, and even more to make them last make power as well.

There is also a certain amount of luck with anything that is mechanical, and we have good luck with what we do. I will say that "Laziness" and sloppy work are two things that kill these engines just like crappy parts that we find all the time.

The TIV engines worst enemy is the wrong mechanic armed with a 13mm wrench.

Dave at Pelican Parts · Dave at Pelican Parts's Garage

I think it's probably easiest just to realize that it's just a style of interaction--and likely a survival tactic, at that! It takes a certain amount of arrogance to think that you can engineer stuff better than the teams of people they had working on these motors back in Germany--and it takes a lot of persistence (as well as some luck, and some talent!) to actually be able to pull it off.

A high proportion of the mechanics that I know that I feel are "excellent" have very specific ways of doing things. They usually aren't shy about letting you know if you do something that contradicts those ways. ("Those things are aftermarket junk--get them the h**l out of my shop!" is something I've heard from more than one of them.) If Jake comes off a little arrogant in his posts, consider the fact that it's probably well-earned. I'm betting that it's also a way to avoid some of the more simple/silly questions, and arguments about some of the more basic things. You'd be amazed at some of the questions people send to me....

...Hey, at least he isn't Br@d!!

--DD