Return to Website

Welcome to the Austin Seven Friends web site and forum

Please read "Change forum" post!

As announced, board is switched to "view only" - mode until closure for backup.

Link to the new forum: http://www.austinsevenfriends.co.uk/forum

Forum: Welcome Austin seven Friends
This forum is locked and posting is not allowed
Author
Comment
Special Engine

Dear all,

I'm Alex, from France. (sorry, nobody is perfect). I try to rebuild my Rosengart Engine (same Austin Seven).

I have a block. This block was bore for piston +40 but I need to bore again (+60 !!) because it's not clean.

I have an idea. I prefer to add cylinder liner than piston +60. Possible ?
When I check online catalogue in A7 shop I can't find the external size of cylinder liner.
And the internal size ?

My idea, is to use my block, add cylinder liner, use Renault 4 pistons, Renault 4 con-rod and phoenix cranckshaft ( 1-5/16 inch ).

Thanks for your answers.

Location: Bretenoux (Lot 46) France

Email  
Re: Special Engine

hi,

when you say the block hasnt cleaned. is this due to poorus spots in the bore.

also arent renault rod for 1 1/2 cranks.

tony

Location: huncote on the pig

Re: Special Engine

From memory most of the liners I have fitted were 140 thou oversize - internal should clean up at standard.

In addition to Tony's comments, all of the blocks I have seen with Honda Pistons had to have 40 thou removed from the height of them.

Why are you thinking of using Honda pistons?

Email  
Re: Special Engine

Hi Ruairidh,
Alex says Renault 4 pistons and rods.
Steve V.

Location: Polegate, East Sussex, United Kingdom

Email  
Re: Special Engine

Thanks Stephen - too much sherry it would seem

Hic!

Why are you planning to use Renault 4 parts?

Email  
Re: Special Engine

Quote: Ruairidh Dunford
Thanks Stephen - too much sherry it would seem

Hic!

Why are you planning to use Renault 4 parts?

Location: Polegate, East Sussex, United Kingdom

Email  
Re: Special Engine

I've just rebuilt an engine that was fitted with +50 thou pistons. They were JP from Australia and were able to supply new +50 thou rings for the same price as any other size available in the UK (although import duty bumped it up). I couldn't source +50 thou rings from the UK.

I understand boring out to +60 thou can be leaving the liners too thin and so was happy to be able to just fit new rings.

Re: Special Engine

I would like to use renault parts because I have a stock of Renault 4 pistons and conrod.
They are compliant with phoenix crankshaft 1"5/16.

And the conrod from phoenix are really to expensive.

Best regards,

Email  
Re: Special Engine

I understand Alex - I shall be back in the workshop in the new year and can measure a liner for you then, if nobody else does so before then.

Email  
Re: Special Engine

Hi Alex. I thought the R4 pistons were either 56mm (Early) or 58mm.
Many over here used to use R4 pistons and rods.The earlier R4 rods had a 38mm journal size which is compatible with the 1 1/2" pheonix crank (which uses R4 shells)
Liners, Westwood liners list WCL 128 as 55,88 bore and 58.98 outside.
or WCL2 57 bore and 61 outside.
Many here have used the 58mm Renault pistons in a 7 block without problems,I have used a linered block bored to +060 but normally +040 is the recommended limit.
I wouldn't use the larger liners at 61mm they weaken the base of the block and the top face too much.

Location: Channel Islands

Email  
Re: Special Engine

Dear all,

Thanks a lot for your responses.

If I understand :

Currently, my block have got piston +040 but I have to bore more (+060).

Instead of bore again, I can bore to adapt cylinder liner from Westwook.
After that I bore the cylinder liner to adapt Renault 4 pistons in size 58mm (????? the liner is now really "thin" no ?).
For con-rod, I can use Renault 4 rods with size 38mm
For the crank, a phoenix crank in size 1"1/2.

Right ?

Location: Bretenoux (Lot 46) France

Email  
Re: Special Engine

I wonder if your recommendation isn't this configuration :

Bore my block to use Renault 4 piston without (!!) liner.
Use Renault Piston in size 58mm and Renault rod size 38mm and a phoenix crank 1"1/2.

Right ?

My aim is to use my car only on the road but with honorable performances. In add to this configuration I plan to use a specific head cylinder, camshaft, sump and oil pump.

Thank again you for your help

Location: Bretenoux (Lot 46) France

Email  
Re: Special Engine

Use the R4 rods 38mm and 1 1/2" phoenix crank yes.
I thought there was a 56mm piston made for export market R4's,maybe someone can confirm this?
I would have the block bored to suit the 58mm pistons,If it is ok,no porosity use it.If you need to liner it you may need to consider using Austin or rosengart rods and readily available smaller pistons if the 56mm R4 pistons are unavailable.
There is not enough metal in a standard block to reliably use the oversized liners in my opinion.

Location: Channel Islands

Email  
Re: Special Engine

Dave, I believe the early Renault 750/4 pistons are 56mm. I am running a set in one of the specials in a standard bore block. Someone who knows more will probably be able to give chapter and verse.

Regards,
Stuart

Email  
Re: Special Engine

Quote: Alexandre BILLAUD
I wonder if your recommendation isn't this configuration :

Bore my block to use Renault 4 piston without (!!) liner.
Use Renault Piston in size 58mm and Renault rod size 38mm and a phoenix crank 1"1/2.

Right ?

My aim is to use my car only on the road but with honorable performances. In add to this configuration I plan to use a specific head cylinder, camshaft, sump and oil pump.

Thank again you for your help



That, Alexandre, is exactly the configuration of the engine currently in my 1929 Chummy. It has done over 10,000 trouble free miles since being built from a collection of parts. (should point out, splash lubricated 11/2" Phoenix crank.)

Good luck with your project.

Ian Mc.

Location: Shropshire

Email  
Re: Special Engine

I understand Alex - I shall be back in the workshop in the new year and can measure a liner for you then, if nobody else does so before then.

Get your own FREE Forum today! 
Report Content ·  · Web Calendars   Online Photo Albums   Free Blogs   Free Guestbooks 
Powered by Bravenet