engine and drivetrain Tii cam and header question

[bnam]

The 74 Tii that I bought came with an IE 292 cam and IE triple Y header and 9.5:1 pistons + heavy duty double valve springs.

It ran poorly, but Schatz & Krum has tuned it so it idles ok and when I took the slop out of the linkage with new bushings, etc it ran much better.

From what I've been able to search so far, the majority opinion is that the Tii K-fish works best with the stock cam as it can run rich at idle and lean above 3500 with a 292. I understand the options are to put in a Wes INgram linkage, remap the cone, or go stock.

My K-fish was rebuilt at some point by an expert in Redding CA (forget his name right now). I will try to see if he remapped the unit -- though I think the rebuild was done before the cam.

It's got me thinking about going back to stock. Is it relatively easy to swap back to stock? Engine currently has about 5-7K miles after the cams were put in.

What about the header? Is the header any benefit with a stock cam?

Thx,

Byas

[tlapham]

Since you have to ask i would probably say no... Although it can be done in an hour or so with the special tool to push down all the valves at once, and it keeps the rocker arms out of the way.

My tii also has a 292 cam, I don't really know what kind of horsepower difference it makes since i've never driven a stock tii, but it doesn't make sense to me. its not like these were slow or something, and a few extra ponies would make a huge difference...

I definitely have a hard time troubleshooting and tuning with this cam though, it seems impossible to make her purr at idle and keep it from pinging slightly above 4000 RPM at full throttle. So i live with a lumpy idle and hard cold starts. oh well.

[AustrianVespaGuy]

Just my personal biased opinion, but if I were in your position and not too worried about originality, I would consider removing your Kugelfischer setup and selling it (worth a lot of $ if it's complete and in good condition) and installing a Megasquirt EFI with an early 320i manifold so as to keep the tii 'look' (such as this: http://www.hbci.com/~tskwiot/2002.html). Since you've already got the internal upgrades I would wager that you would see EXTREMELY improved performance with properly tuned fuel delivery (which I think you are correct, the Kugelfischer probably isn't accomplishing with the modifications). I also think this wouldn't be any more work (and probably less) than tearing apart your motor internals in an attempt to return them to the stock condition. You would essentially loose the 'heart' of what makes your car a tii, but you would very likely gain a much better running car. Just some food for thought, and feel free to email if you have any Megasquirt questions (I run it on my normal 2002, but with 318 hardware).

-Carl

[bnam]

I've read a bit about megasquirt, but on this car I am interested in sticking to originality.

B

[markmac]

If you have a real deal tii which I assume you do, I am going to suggest, no, not, nyet, don't do it to any sort of changing to carbs, changing to megasquirt or anything else. Change the cam. Fairchild (Redding) probably did a stock kf rebuild. To be honest I have never heard of anyone being able to get a tii with standard single throttle intake to run right with a Schrick 292 cam - the various problems (lumpy idle etc.,) are consistent with anyone I have ever checked with or heard chime in and that is more than a few. The ALPIna A4 system with a 300 cam AND a correct ALPINA kf pump is a different story. Go back to a stock cam or a Schrick 284 - it is my understanding that the 284 works fine with stock kf pumps and gives you a little extra bite. A well dialed in tii with a stock cam often will run stronger than a modified version of the same. I can recall reading an article from Dave Redszus about tii's and that because of a variety of reasons kf pump problems, linkage, worn valves, guides, pistons, ignition etc., it wasn't uncommon for a tii to make 100 - 115 hp or so without the owner even knowing it. Fresh engine components + KF system in proper order + ignition = 130+ hp and a proper running tii.

www.alpinabmw2002.com

[bnam]

To switch back to regular cam, what parts would I need to get? Just a stock cam? Was the cam specific to a Tii or same as Carb version?

I am currently renewing all the Kfish parts. Pump was already rebuilt. Got new bushings in place plus a few new ball ends. Linkages adjusted to the correct length. New intermediate shaft. Good used throttle to replace my worn throttle. Rebuilt clamp. Will gasket match the runners and plenum. New gaskets, hoses, clamps, etc. Resynch the pump and throttle.

Replacing the current K&N filter set up with the original airbox and hoses.

Running a relatively new Tii distributor (though not the 74-only one with Retard). Wiring is good. Will check points gap, dwell, sparkplugs etc.

Will hopefully get all these done this weekend. Then enjoy the car, while I investigate what it take to get back to stock cam.

While replacing the cam will also plan to go back to stock tensioner vs. the racing tensioner that's on there now. And renew the gaskets to hopefully cure a leak from the bottom of the timing top cover.

Byas

[ray_]

Ooooh! those are fun to fix! Mine did that. If the head was milled, the top cover should have been also.

GL,

Ray

to hopefully cure a leak from the bottom of the timing top cover.

Byas

[markmac]

No diff bewtween an o2 and tii as far as stock cams go. One thing that often goes ignored - have a good look at your throttle body. After 28 years of wear and tear, often the throttle shaft bushings are toast and sometimes even the throttle plate has wear and tear. Something regularly and often missed. Even minor (very minor) things on a tii can mean the difference in running just good (or great) as you know. I think Redszus (PAR) used to match your distributor/ignition with the pump (not really sure what that entailed or was, but recall reading something about it once upon a time). Stu Krum is very good, so you are in good hands. I am hoping to steal some of his time this weekend as a matter of fact....BTW, I believe Wes Ingram can do bushings on tii TB's, he could probably even give you a few more MM's by boring it out a little and putting a little larger plate in, but then that might open another can of worms.

[markmac]

No diff bewtween an o2 and tii as far as stock cams go. One thing that often goes ignored - have a good look at your throttle body. After 28 years of wear and tear, often the throttle shaft bushings are toast and sometimes even the throttle plate has wear and tear. Something regularly and often missed. Even minor (very minor) things on a tii can mean the difference in running just good (or great) as you know. I think Redszus (PAR) used to match your distributor/ignition with the pump (not really sure what that entailed or was, but recall reading something about it once upon a time). Stu Krum is very good, so you are in good hands. I am hoping to steal some of his time this weekend as a matter of fact....BTW, I believe Wes Ingram can do bushings on tii TB's, he could probably even give you a few more MM's by boring it out a little and putting a little larger plate in, but then that might open another can of worms.

www.alpinabmw2002.com

[bnam]

Yes, I had my throttle looked at by an expert and am replacing with a good one.

[Pierre]

I have a 292 in my tii with 9.5:1 pistons and an airbox delete setup. The PO rebuilt and internally re-calibrated the KF to work with the mods. I have a stock exhaust all the way through. It pulls stronger than a stock tii from 4000 all the way to 6500. The torque is a little lower than stock at lower engine speeds as expected from a 292.

Fairchild or Redzus may be able to reconfigure your KF if you give them your engine specs so that the engine power can be extracted. Tuning the KF is also an art few know how to do right. But once they are set, they pretty much work for a long time with little interference.

[Armond]

I have spoken to Redzus a month ago about "re-configuring" a stock KF pump to "match" a particular cam/engine specs and he said it cannot be done. "No such thing" he says. Perhaps you can replace the cone? good luck sourcing one.

[markmac]

It is hard to say how a standard tii single throttle injected motor would work with a pump with a different cone (say an ALPINA A4 pump or pump cone). Since the air flowing through four throttle plates is going to be much different than one single throttle butterfly. No doubt it would work better than a standard pump that has been jacked around with but if I had to guess it isn't going to work as well as either a properly dialed in standard tii or a complete AlpinA A4 (with correct pump), both of which are things of beauty when dialed in. I separated my A4 system from my tii before I sold the car and it had a factory 300 cam, unbelievably bad with a standard pump - no idle less than like 3500 rpm, crazy power up after 5 on up to 6500+ although I am sure it was running way lean. That said a factory 300 is a bit of a different beast than even a Schrick 292. As I recall, Michael has his tii pretty well dialed in (with A4 injection) and a standard pump.

www.alpinabmw2002.com

[bnam]

I've never done (or had done) a cam swap. Apart from the cost of a standard cam -- any guidance on what I can expect (timewise -- and I can translate into $) for an experienced shop to swap out the cam? Just trying to figure out what I need to budget.

Thx,

Byas

[c.d.iesel]

Rremove and Rreplace cam shaft M10

remove cylinder head

clamp down rockers to R&R cam

optional work - pressure test head, skim head/resurface

attention to valve and seats

assemble

reinstall head

depends on your location in the country for labor rates

LOW = estimate just for labor? $1000

HIGH = estimate just for labor? $ 1900

you see - when you pay an expert for proper

R&R , you need to factor 30 year old car, replaceing

anything that is rusty, broken, weak. Things that

would make the car 'come back' because of leakage,

smoking, noises, poor performance. Doing the

labor yourself cuts the expense, and you are

responsible for any failures after the repair.

Let a shop do the repairs and you better be

dealing with people that will correct any mistakes

on their part. If you just insist that the shop

does a 'quick job- don't expect any guarantee that

everything willbe golden. IT'S A 30 YEAR OLD CAR.

And a quality shop will refuse to do a 'quick' job.

and your question about the exhaust header? - it's a non issue - -

BUT some can argue that the tii injection pump was developed

and calibrated to produce the correct air/fuel ratio, and smooth

power delivery across the entire rpm range with the original

air cleaner and cast iron exhaust manifold. Anything you

change from the 'stock' arrangement may effect the smooth,

progressive performance that the motor had when it

rolled off the assembly line.

BMW engineers had dynometers, injection pump flow test

benches. Do you ?