Jump to content
mvliotta

tii engine rebuild and 5 speed swap

59 posts / 2951 viewsLast Reply

Recommended Posts

Will be using this thread as I go through the engine rebuild and 5 speed swap for Liesl, my ‘72 tii.

 

The real hard and dirty work started today with engine removal. 

 

Here is the valve train before the head came off. Lots of nice shiny bits as this was done by the PO less than 20k miles ago. 

50DF344E-B78D-4226-A2C3-5C4A090032A0.thumb.jpeg.5627ad92c2c07d13faff3a3bf29c8a11.jpeg

 

Out came the bottom end once it got freed up from the trans....not shiny as was probably never rebuilt. 

 

C0E0303F-B034-4E3E-ACAD-82FF525843EB.thumb.jpeg.513968d3ffc11cd4e230bf26378f1dd3.jpeg

 

Top of pistons with lots of carbon build up. Deck looks good otherwise... I think?  No issues with the head gasket. 

What say you wizards? Anything else catch your eye?

BA165A4C-A9CC-4120-93B2-CD01D8181D38.thumb.jpeg.1be0db43b15397abdb74172df86dde4b.jpeg

 

2F8E3A02-0E27-40F6-BF82-A714136CA063.thumb.jpeg.d3765ad9f6a237341988877da840c930.jpeg

 

Engine on a stand till next wknd, when it will be further stripped down. Pistons and rings will come out then and then will figure out next steps!!

 

A3AD0706-2CC4-4F45-BD5D-3608FDD7D1C2.thumb.jpeg.adabaf40f7896605b444138d7d6648ac.jpeg

 

Vince

 

 

  • Like 2

Share this post


Link to post
Share on other sites
(edited)

Ooo la la, Vince: your Ceylon is showing!
 

This is great! There appears to be a lip in the cylinders from the top rings, but — to cut to the chase — the machinist’s measurements will determine whether you will be boring for oversize pistons, and, if so, to what oversize?

 

I forget your car’s VIN, but I’m assuming it is an example with a 121 head, as suggested by the bathtub-top pistons.

 

Best regards,

 

Steve

 

 

 

Edited by Conserv
  • Like 1

Share this post


Link to post
Share on other sites
1 hour ago, Conserv said:

 

Oo la la, Vince: your Ceylon is showing!

 

Yes, she is a temptress, this one. Part of her mystique is the tri-color engine bay!

 

And, yes, 121 head. Once I get the pistons out, will be scratching my head about whether to go to higher compression. The stock 264 cam was replaced when the top end was done, so leaning toward keep it as it’s in great shape. 

 

Vince

  • Like 3

Share this post


Link to post
Share on other sites
(edited)
 

 

Once I get the pistons out, will be scratching my head about whether to go to higher compression. The stock 264 cam was replaced when the top end was done, so leaning toward keep it as it’s in great shape. 

 


Vince,

 

Whether to choose 9.5:1 or 10.0:1 is a personal choice. There are multiple threads on here discussing the subject. The primary “risk” associated with the 10.0 ratio is pre-detonation and run-on. Many 10.0 ratio users say they’ve never had a problem (they could detect) as long as they run 93 octane gasoline. A few have said they can use 91 octane without a problem — I’ll admit I question their credibility, or at least their awareness of pre-detonation with 91 octane...  I don’t want to ever worry about having to find 93 octane gas — although it remains available at every Sunoco station — and I’m simply not aware of any great power increase flowing from the .5 bump in compression ratio, so I’m happy at 9.5:1. Others are only happy at 10.0:1.

 

Non-stock camshafts in tii’s are even more controversial and supporters of hot cams in tii’s are less common, the rationale being that the Kugelfischer pump and system were designed around the stock camshaft. Conceptually, the pumps can be modified to deliver the higher volumes of gas demanded by a hotter cam, but there is great deal of vagueness surrounding these Kugelfischer mods, precisely who is qualified to perform them, and how they affect the tii’s overall performance and power band. Even long-time ‘02 tuning shops such as Korman’s recommend keeping the stock camshaft if you’re keeping the Kugelfischer injection.

 

You will find people, generally, but not always, technicians with less knowledge of and experience with tii’s, assuming that a hotter cam is always better. I’d be wary of these people unless it’s absolutely clear they’re aware of, and have successfully addressed, the hot cam-Kugelfischer mis-match! Thus, if an experienced Alpina technician told me, “Yes, the mis-match has always been a concern and here’s how we have addressed it for nearly 50 years,” I’d probably feel comfortable about that person installing a hotter cam in my tii. Remember, despite being old technology — even in 1972 — the stock Kugelfischer injection, when set up by a tii whisperer, is remarkably smooth and powerful across a broad power band. You don’t want to f**k that up! 😉

 

Best regards,

 

Steve

 

 

 

 

Edited by Conserv
  • Like 2
  • Thanks 1

Share this post


Link to post
Share on other sites
 

Whether to choose 9.5:1 or 10.0:1 is a personal choice.

 

Was hoping you would chime in, Steve!

Your knowledge continues to amaze. 

 

Don’t think I’m going to mess with the head. It’s had rockers, stock cam, valve seals (etc) replaced, and the head resurfaced relatively recently. Just going to clean things up. 

05AE4EB5-FD38-46AD-821B-B6A3F435B8D9.thumb.jpeg.86e983e0333c7f29e4f142f9381d5450.jpeg

 

As for the pistons, well, I’m thinking along the lines of upgrading compression to 9.5, as you recommend. Also, for ref, I have an early stock KF pump. 

 

Have to see what’s going on with the cylinders, of course, but where does one find 9.5:1 bathtub pistons, if I go that route? Do I order forged ones from Ireland?

 

Oh, and forgot to mention that I’m running a header (BavAuto one, I think), if that makes any difference at all. 

 

Vince

  • Like 1

Share this post


Link to post
Share on other sites
(edited)

Hello FAQers,

From various sources, seems like it’s a good idea to replace my oil pump as it is probably original. 

I’ve been searching around and W&N has stock ones. Will ask tmrw if it comes with sprocket. 

 

Looks like the other option is to go with an e21 oil pump and change the pick up? 

 

Thoughts?

Edited by mvliotta
.

Share this post


Link to post
Share on other sites

E21 and change the pickup unless you have extra $$$ you don't mind parting with. FWIW I went with the W&N Mahle's first overbore in 9.5:1 for my rebuild. My machinist smiled when I brought him the pistons.

  • Like 2

Share this post


Link to post
Share on other sites

Thanks Adamha. 

 

Just got off the phone with W&N. 

 

They have the stock oil pump and sprocket for basically the same price as the e21 version that can be found elsewhere, so will just get the stock one. 

 

As for tii pistons with a 121 head (bathtub), the only ones they have are those with a 10:1 compression ratio at the second oversize (+0.5mm). 

 

Will reevaluate once I pull pistons and check out cylinders. 

Share this post


Link to post
Share on other sites
(edited)
 

 

... As for tii pistons with a 121 head (bathtub), the only ones they have are those with a 10:1 compression ratio at the second oversize (+0.5mm). 

 

Will reevaluate once I pull pistons and check out cylinders. 


Good strategy, Vince!
 

Step one: figure out what size oversize your engine needs.

 

Step two: look around a bit — there are still lots of NOS pistons kicking around.

 

Best regards,

 

Steve

 

Edited by Conserv
  • Like 1

Share this post


Link to post
Share on other sites

I would add, and will always add, balance it.  It's worth it.

 

Personally, aluminum flywheel is worth the cost.  Get that balanced with the rest of the lot.

  • Like 2

Share this post


Link to post
Share on other sites

Measure the head thickness, and then cc it for good measure.

 

You buy pistons that have a compression spec on them, but that's at stock 

head volume.  If your head volume is different, the compression ratio will be different.

Both head and valve thickness alter it, as will how deep the valves have been set into the head.

Takes about 30 minutes, once you've worked out how, and made your plexi plate, and then

redrilled the holes a few times to make it work better....

Also, break the sharp edges on the head where they protrude into the

chamber.  Don't put a big radius on- just a fine one, 1/32" is enough.

Helps no end with hot spots.

 

Likewise, cam overlap plays a big part in lower- rev detonation, as it affects static

compression ratio.  A modern, dual VANOS BMW head claims 10.5:1 compression,

BUT it can easily alter that by changing the relationship between the intake and exhaust 

cam, reducing overlap if the engine starts detonating, as well as pulling timing, richening mixture,

and turning on your seat heater.

So while there are a few 'number' cams that everyone uses, cams can be ground in thousands

of ways that work well....  but stock will always be safe with a tii.

 

As to that fuel delivery cone in the KF pump... 

Well.  It's a miracle of steam- age ingenuity and hard, practical science.

I want to replace it with an engine computer, and have electro- mechanical injection!

 

t

off the rails.  Needs a beer.

  • Like 2

Share this post


Link to post
Share on other sites
(edited)

Thanks for the encouragement and info thus far, gents!

 

Today, Paul (Guru who is guiding me through all of this) and I spent a few hours stripping the block. 

 

Found that the oil pump chain was pretty loose, but otherwise, everything was intact. 

027C59AC-A61B-4D18-ABC8-667F66459EB3.thumb.jpeg.c873f739dad89bd04e8d8ed2e1f07c9f.jpeg

 

The exciting part part was pulling the cylinders and crankshaft and measuring. 

 

Confirmed that pistons and block came with this car and the bottom end was never rebuilt. No rebore on the cylinders and crankshaft journals (?) are within original spec. 

 

A3DB523A-875C-46DF-B353-094288B19A89.thumb.jpeg.dc7c9e0db824cf5ab0ae97d352d71aa2.jpeg

 

11975765-24C5-4E26-B659-47C26F9678AB.thumb.jpeg.e1962bc5c59e146e90143b922b7ca10e.jpeg

 

Now the pistons!

 

16EA9365-B2FC-481C-9C63-CD4BEEB94870.thumb.jpeg.6a0d7b2a25a92fb0a92c3bce491857c9.jpeg

 

Some wear on each piston with matching wear in the cylinder. Bet the rings are worn down as well and was

the cause of my smoky deceleration. 

 

Also confirmed the head had a minimal resurface done as that measures in at 129mm. Will keep the top end as is with refreshed stock cam, rockers, etc. 

 

Time to decide between piston options and corresponding work on the block. Here is what I’ve been considering and out there for the 121 head...

 

Option 1: Mahle 90mm (+1mm) pistons with 10.0:1 CR widely available

 

Option 2: Mahle 89.5 (+0.5mm) pistons with 10.0:1 CR from W&N

 

Option 3: Custom forged pistons, probably 89.5 (+0.5mm), probably 9.5:1 CR from Ireland Engineering

 

Option 4: Something I have not thought about or found

 

Decisions, decisions. 

 

Please share your opinions!

 

 

0C4A1291-2EEC-481F-B614-DB357549B52A.jpeg

Edited by mvliotta

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.




×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.