engine and drivetrain Tii Head Build Advice

[Inka_Ryan_02]

I have just received my brand new head blank for my ’72 tii. It came with new seals and guides. I plan to swap out the remaining parts from my original head which has a 292 cam. I purchased new valves and seals, but plan to reuse my double valve springs and rocker arms. I have a few questions that I hope you could answer:

 

Do new valves need to be lashed?

 

Can I reuse my rocker arms with confidence? What metric do I use to determine if they’re still good?

 

Are double valve springs overkill for a 292 cam and should I buy new stock springs or are my double springs ok?

 

Lastly, what is the best machine shop in San Francisco for the assembly? I have contacted Terry Tinney, but I do not have a car and the shop is at least an hour away. I can’t carry 50 lbs of heads on the bus to the shop.

Thanks for the advice.

[Preyupy]

The valve seats in the head need to be checked to make sure they are concentric with the guides (the factory is not great at this) the valves and seats need to be cut at the same angle. The dual valve springs are ok but probably more than you need with the 292 cam. You have them so go ahead and use them. If you are going to reuse your rocker arms and camshaft make sure the rockers go back on the same lobe they have been running on. If you are planning on doing track events with this car make sure you have GOOD rocker arms ( there are a lot of aftermarket rockers out there that are absolute crap) You could always ship the heads to Terry, he would be my choice down there.

[hanksjim1]

How's that 292 working with your kfish on your Tii?  I have read a lot of threads that say 285 or so max for good drivability.

[Inka_Ryan_02]

So when you say the valve seats need to be concentric with the valve guides are you saying that the guides are not always centered within the seat? How do they fix that? Also, should I plan on having machine work done to the seats and valves? 

 

Thanks

Edited September 27, 2013 by Inka_Ryan_02

[Inka_Ryan_02]

Well, the 292 cam when set up right really screams at the high end. Its a lot of fun.  I have had problems at times getting the engine to idle smoothly and tuned right. Recently I replaced the rods to the pump and butterfly. I think  a lot of the sloppiness was from the rods being bent from prying off the ball joints and changing the actual length, which made the tuning...well incorrect. I am at the point now where everything has been replaced and I am hoping that the new head will take the car to the level it should be at.

Edited September 27, 2013 by Inka_Ryan_02

[AceAndrew]

 ( there are a lot of aftermarket and OEM rockers out there that are absolute crap)

 

Edited this little bit.  But all very good points.

 

What dual valve springs do you have?  If Schrick then I'd personally change them out to some heavier duty single valve springs if your planning on having the engine last for a long time.

[Inka_Ryan_02]

Geez, I don't remember who manufactured them ( I bought them in '92), I know they're not schrick. They may even be CHEVY...My uncle was heavily involved with drag racing and was familiar with all of the race shops in LA. He helped me to get the engine machined and setup. He also got me a set of +1 forged aluminum pistons from ARIAS ($350), which I think they do not normally make anything for BMWs. The engine ran great and produced a lot of power, but corrosion got the best of the 40 year old head.

 

Are you saying the double springs cause more wear on the rocker arms?

Edited September 27, 2013 by Inka_Ryan_02

[Preyupy]

Well, the 292 cam when set up right really screams at the high end.

I'm not sure what your definition of "really screams" means but I have been running a 316 in my car for over 15 years and the new engine has a 336 in it. The load on the rocker arms is not a problem as long as you are running some added Zink/Phosphorus in the oil (ZDDP additive) the worst thing that can happen is if you float the valves at high RPM, YOU WILL BREAK ROCKER ARMS!!! I only use factory rocker arms unless I am running the high strength racing rockers $$$$. The aftermarket rockers are crap. If you are going to do any track events or like to spend a lot of time 5000rpm and above you need to be careful.

[Inka_Ryan_02]

Thanks, Preyupy, but you did not answer my other question about the seats and valves you brought up earlier. And the valve seats/guides.

 

Regarding your comment about "screaming", the car certainly pulled a lot harder with the cam than stock. Next time I will confer with you on the appropriate adjectives that I can use to describe my performance.

 

Lastly, I see that you have a turbo and a 1600, which car is the 316/336 cam in. Or is it in the M5? Should I assume its not  the turbo because of the K-pump? If it is the turbo, how'd you modify the pump to cope with the cams?

[tlapham]

My tii has a 292 (previous owner) and although it idles a bit lopey, puttering around in parking lots is a bit jumpy, (but I also have some sort of PO racing clutch to thank for that) it does scream when you open her up. 0-100 is dangerously easy. (5-speed helps, too)

 

I have driven a 2002 with weber 32/36 and it was pretty fast, but never a stock tii...

Edited September 27, 2013 by tlapham

[Preyupy]

Sorry, forgot about the seats. If you talk to any machinist they will want to make sure the valve seats are concentric with the guides. The way they do this is run a pilot in the guide and touch the seats with the cutter and make sure everything is right. I would never take a new valve, and a new head and just assemble them assuming the seat and valve face are the same angle or that the factory got the guide and seat right on (THEY ASSUME someone will check it before they assemble it.

To answer your other question, the 1600 has had a 2 liter in it since 1978 (300 cam 10:1 comp ratio and 40 DCOE's) Then in 1988 I built another 2 liter (316 cam 12:1 comp ratio with 45 DCOE's + LOTS of head work ie full Hemi domes etc) I just finished another 2 liter (actually 2012cc, 336 cam 12.8:1 comp ratio, Big valves, even more head work. 45mm ITB's, electronic FI forged steel rockers, dry sump) The Turbo is restored to completely stock, except for the Bilsteins and MiniLite wheels.

[TobyB]

Wow- I didn't think a new head casting was available...

 

and as to valve springs, if you stick with the  stock rev limit (or a little under),

stock springs are ok for a 292.  If they're in good shape.

 

 

t

[cjeria]

Lastly, what is the best machine shop in San Francisco for the assembly?

 

Hi Inka, did you find a reliable machine shop in or around San Francisco? I also live in SF and I need to have my cylinder head and engine rebuild. Thanks.

 

- C 

[Ringworm02]

I had my head assembled by Terry Tinney in Livermore:

 

http://www.terrytinney.com/