The Triumph Dolomite Club - Discussion Forum

The Number One Club for owners of Triumph's range of small saloons from the 1960s and 1970s.
It is currently Thu Mar 28, 2024 12:34 pm

All times are UTC




Post new topic  Reply to topic  [ 7 posts ] 
Author Message
 Post subject: 1500 Bore Size?
PostPosted: Mon May 04, 2020 12:18 pm 
Offline
TDC West Mids Area Organiser
User avatar

Joined: Thu Sep 28, 2006 1:13 pm
Posts: 13316
Location: Over here...can't you see me?
What is the standard bore size for a 1500 please?


Top
   
 Post subject: Re: 1500 Bore Size?
PostPosted: Mon May 04, 2020 12:35 pm 
Offline
TDC Member
User avatar

Joined: Fri Oct 06, 2006 9:57 am
Posts: 669
Location: Auckland, New Zealand
Pretty sure it is the same as the 1300 at 2.9000in (+/-0.5thou). Max oversize is 0.020in. Extra capacity of 1500 is due to longer stroke.


Top
   
 Post subject: Re: 1500 Bore Size?
PostPosted: Mon May 04, 2020 12:51 pm 
Offline
TDC Member
User avatar

Joined: Wed Nov 15, 2017 3:35 pm
Posts: 956
Location: Filey, North Yorkshire
73.7mm or as above 2.9"
I'm running my 1500 engine at +60 overbore though... :-)

_________________
Image


Top
   
 Post subject: Re: 1500 Bore Size?
PostPosted: Mon May 04, 2020 12:55 pm 
Offline
TDC West Mids Area Organiser
User avatar

Joined: Thu Sep 28, 2006 1:13 pm
Posts: 13316
Location: Over here...can't you see me?
Thanks both.

Set of new standard pistons ebay bound shortly!


Top
   
 Post subject: Re: 1500 Bore Size?
PostPosted: Tue Mar 30, 2021 7:37 pm 
Offline
TDC Spares Officer

Joined: Sat Feb 18, 2012 11:43 am
Posts: 153
Location: Shaftesbury
Hi All

I am looking to buy some new pistons and rings for my 1500 rebuild...

I have contacted a supplier who suggest based on my measured bore size that I need +.0020” ones but I am not convinced...

Measured bore size is 73.74 on 3 bores and 73.71 on the other. Workshop manual says 73.65 nominal giving 0.06 to .09mm bigger.

Based on 73.59mm nominal piston (from the workshop manual) if I go oversize by .0020”. (.502mm) this would make the piston too big at 74.09mm...so too big..

I suspect he is thinking I am going to re-bore based on the wear, but apart from that they are in good condition.

Am I hopefully I can get away with standard pistons and an oversize piston ring.. or am I way out on my calculations...

_________________
Triumph Dolomite Club Spares Officer
Track day Sprint for track fun....
1500TC for summer time daily use...
Skoda Superb 4x4 for everyday use...


Top
   
 Post subject: Re: 1500 Bore Size?
PostPosted: Thu Apr 01, 2021 12:14 pm 
Offline
Future Club member hopefully!
Future Club member hopefully!
User avatar

Joined: Mon Jun 03, 2013 5:48 pm
Posts: 1635
Quote:
Hi All

I am looking to buy some new pistons and rings for my 1500 rebuild...

I have contacted a supplier who suggest based on my measured bore size that I need +.0020” ones but I am not convinced...

Measured bore size is 73.74 on 3 bores and 73.71 on the other. Workshop manual says 73.65 nominal giving 0.06 to .09mm bigger.

Based on 73.59mm nominal piston (from the workshop manual) if I go oversize by .0020”. (.502mm) this would make the piston too big at 74.09mm...so too big..

I suspect he is thinking I am going to re-bore based on the wear, but apart from that they are in good condition.

Am I hopefully I can get away with standard pistons and an oversize piston ring.. or am I way out on my calculations...
You've given them the measurement of the bore, they think you've given them the piston size hence them saying you need a bigger piston.

_________________
Some people are like Slinky's, they serve no real purpose in life but bring a smile to your face when you push them down the stairs.


Top
   
 Post subject: Re: 1500 Bore Size?
PostPosted: Thu Apr 01, 2021 3:41 pm 
Offline
Future Club member hopefully!
Future Club member hopefully!

Joined: Thu May 17, 2012 9:34 pm
Posts: 867
Quote:
Am I hopefully I can get away with standard pistons and an oversize piston ring.. or am I way out on my calculations...
No. You can't use oversize rings on standard pistons.
Based on your measurements your machine shops advice is correct, you need to rebore and then use appropriate oversized pistons.


Top
   
Display posts from previous:  Sort by  
Post new topic  Reply to topic  [ 7 posts ] 

All times are UTC


Who is online

Users browsing this forum: AhrefsBot [Bot], Amazon [Bot], Bing and 21 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Limited