Jump to content

Welcome to the brand new 205GTIDrivers.com website! We hope you'll enjoy it! Read the full notice here.

  • Welcome to 205GTIDrivers.com!

    Hello dear visitor! Feel free to browse but we invite you to register completely free of charge in order to enjoy the full functionality of the website.

wld

Liner/piston class matching

Recommended Posts

wld

I just got (for an unbeatable price) a set of NOS Goetze 8v liners to use in the mi16 (D6C) that I'm starting to rebuild in few weeks. The engine was working when the car was taken off the road several years ago, so I plan to reuse the D6C pistons.

Problem is that the new liners are "A class" 83.00 to 83.01mm and the pistons are C class (82.983-82.997mm), as stamped on them. The engine is still in the car, so measuring them is not an option at the moment. I used an endoscopic camera to read the markings.

Engine has around 200.000km so the pistons are worn, but will they be worn enough not to seize when hot?

Anybody can shed some light over this?

Thanks

 

 

Share this post


Link to post
Share on other sites
wicked

They only wear at the crown of the piston usually, so still I would not just drop C pistons in A liners. 
You can hone the liners to give them a bit more clearance, but would not do that until you take the engine apart.

If they are not reusable, you have to find other pistons and most pistons are B class.  

Share this post


Link to post
Share on other sites
dcc

Potential to fit some new pistons with bigger valve cut outs for more lift :)

Share this post


Link to post
Share on other sites
wld
3 minutes ago, dcc said:

Potential to fit some new pistons with bigger valve cut outs for more lift :)

Not what I had in mind (or bank account) :D

Bodywork and paint will eat most of the budget. It's a street car (BX 16V), destined to be registered as an oldtimer, so it has to be reliable and without any visible mods. I have a Stage1 camshaft from Peter Taylor, so I'll probably use it as nobody cares, and they cannot measure it.

Share this post


Link to post
Share on other sites
wld
6 hours ago, wicked said:

They only wear at the crown of the piston usually, so still I would not just drop C pistons in A liners. 
You can hone the liners to give them a bit more clearance, but would not do that until you take the engine apart.

If they are not reusable, you have to find other pistons and most pistons are B class.  

Thanks!

Is honing possible without the expensive fixture needed for clamping them tight?

Share this post


Link to post
Share on other sites
wicked

If you want to over bore liners to larger size, you do, but for honing not. 

Share this post


Link to post
Share on other sites
DamirGTI

For re-bore and hone yes , you do need the liners clamped down with an fixture/plate .

 

For liner deglaze , no need for fixture/plate .

 

 

D

Share this post


Link to post
Share on other sites
petert

If you're honing out half a thou, you definitely need a fixture which reproduces the compressive load(s) of being clamped in position.

 

What does this mean?
"I have a Stage1 camshaft from Peter Taylor, so I'll probably use it as nobody cares, and they cannot measure it."

Share this post


Link to post
Share on other sites
wld
3 hours ago, petert said:

What does this mean?

"I have a Stage1 camshaft from Peter Taylor, so I'll probably use it as nobody cares, and they cannot measure it."

That must have sounded weird :) unless you read that I want it to be registered as a classic car.

In my country, and many others in Europe, the car has to be completely original to get the classic car papers. Of course, it can be restored, but without any modifications. According to the rules, even the camshaft has to be stock, but the people checking the originality have no way of knowing, or measuring that. Of course they have no way of checking the pistons, but I'd rather not spend the extra cash, as the bodywork, paint and fixing the hydropneumatic suspension of the Bx will be a big chunk and I'm not loaded...

Share this post


Link to post
Share on other sites
DamirGTI
7 hours ago, wld said:

In my country, and many others in Europe, the car has to be completely original to get the classic car papers.

 

Same here .. no way of passing an MOT if the car has been modified , suspension not so much but (different type) engine fails instantly . And to make it road legal with say larger engine needs special certificate , the amount of paperwork needed , time , money and effort to do so is just outrageous - slow complicated to the bone and expensive ... if you even pass at the end , got the certificate .

 

Eastern Europe :wacko:

 

D

Share this post


Link to post
Share on other sites
petert

Yes, that Stage I profile still has a smooth idle when used with a standard exhaust cam. It's a magic combination.

  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×