ausmini • View topic - How much compression?

Board index » Mini Chat » Mini & A/A+ Series Mods

All times are UTC + 10 hours

How much compression?

Moderators: winabbey, simon k, poeee, Mick

Page 1 of 2

[ 17 posts ]

Go to page 1, 2 Next

Print view

Previous topic | Next topic

Author

Message

mini-dunger

Post subject: How much compression?

Posted: Tue Nov 06, 2007 8:21 pm

1275cc

Joined: Thu Jun 08, 2006 9:34 pm
Posts: 2372
Location: Adelaide

Hi all

1098 +.60, RE13, How much compression should I run? I would do exctly what Sir Vizard says but he is a bit vauge in his book. I have no issues using premium and a octane booster if need be.

Thoughts ?

Thanks guys

_________________

blokeinamoke wrote:

Yep Mokes are ugly - but Moke owners know that. Its like ugly women - she may be a dog but you know your going to get some :wink:

Top

drmini in aust

Post subject:

Posted: Tue Nov 06, 2007 9:01 pm

religious status

Joined: Fri Mar 19, 2004 6:19 pm
Posts: 39753
Location: near Baulkham Hills, NSW

You can use up to around 10.5:1 with an RE13.
My 1310 ran fine with one at 10.4:1.
It used to be 11.0:1, that was too high. Couldn't stop it pinging. :lol:

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R. :mrgreen:

Top

sgc

Post subject: Re: How much compression?

Posted: Tue Nov 06, 2007 9:04 pm

This space for rent

Joined: Thu Feb 08, 2007 12:40 pm
Posts: 5455
Location: Melbourne

mini-dunger wrote:

1098 +.60, RE13

What head you got there?

_________________
Simon

The adventures of an owner builder in the Tallarook Ranges

Top

mini-dunger

Post subject:

Posted: Wed Nov 07, 2007 7:04 am

1275cc

Joined: Thu Jun 08, 2006 9:34 pm
Posts: 2372
Location: Adelaide

its a 12g202 with 33mm inlets and 27mm exhaust valves + about 50 hours :shock:

_________________

blokeinamoke wrote:

Yep Mokes are ugly - but Moke owners know that. Its like ugly women - she may be a dog but you know your going to get some :wink:

Last edited by mini-dunger on Wed Nov 07, 2007 7:26 pm, edited 1 time in total.

Top

drmini in aust

Post subject:

Posted: Wed Nov 07, 2007 6:30 pm

religious status

Joined: Fri Mar 19, 2004 6:19 pm
Posts: 39753
Location: near Baulkham Hills, NSW

mini-dunger wrote:

its a 12g202 with 30mm inlets and 27mm exhaust valves + about 50 hours :shock:

I did the valves, those inlets are 33mm. :wink:

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R. :mrgreen:

Top

Smegger

Post subject:

Posted: Wed Nov 07, 2007 6:42 pm

848cc

Joined: Mon Jan 22, 2007 8:38 am
Posts: 490
Location: Carlingford, NSW

drmini in aust wrote:

mini-dunger wrote:

its a 12g202 with 30mm inlets and 27mm exhaust valves + about 50 hours :shock:

I did the valves, those inlets are 33mm. :wink:

_________________
Gareth.

Top

mini-dunger

Post subject:

Posted: Wed Nov 07, 2007 7:25 pm

1275cc

Joined: Thu Jun 08, 2006 9:34 pm
Posts: 2372
Location: Adelaide

thats what i said

_________________

blokeinamoke wrote:

Yep Mokes are ugly - but Moke owners know that. Its like ugly women - she may be a dog but you know your going to get some :wink:

Top

sgc

Post subject:

Posted: Wed Nov 07, 2007 7:28 pm

This space for rent

Joined: Thu Feb 08, 2007 12:40 pm
Posts: 5455
Location: Melbourne

Why such large inlets? I would have thought you'd get better performance with bigger exhaust valves than inlets... at least on a smallbore.. ?

_________________
Simon

The adventures of an owner builder in the Tallarook Ranges

Top

drmini in aust

Post subject:

Posted: Wed Nov 07, 2007 8:26 pm

religious status

Joined: Fri Mar 19, 2004 6:19 pm
Posts: 39753
Location: near Baulkham Hills, NSW

sgc wrote:

Why such large inlets? I would have thought you'd get better performance with bigger exhaust valves than inlets... at least on a smallbore.. ?

You have exhaust pressure to blow exhaust out. You have 1 atmosphere air pressure only to push it in.
GR uses these valves, and nobody I know gets better power from a smallbore with 202 head.

They are Morris 1100S/1275LS valves, with the exhausts turned down to 27mm and the seat face recut. The inlets are stock dia but have the heads backcut 30° same as Vizard suggests.
To use inlets this size in a 202 head it must be deshrouded severely, it looks pretty much like a 295 chamber when finished.
Here's one I prepared earlier (before polishing)-

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R. :mrgreen:

Top

Lillee

Post subject:

Posted: Wed Nov 07, 2007 9:03 pm

1360cc

Joined: Tue Jun 01, 2004 3:41 pm
Posts: 6858
Location: Special Tuning Sydney

10.5:1 is good enough, anymore and you will ping if you have bad fuel. I run 10.2:1 and when cold and on bad fuel I can hear her ping...

_________________
Lillee - 1969 Morris Mini K

Top

willy

Post subject:

Posted: Wed Nov 07, 2007 9:04 pm

1360cc

Joined: Mon May 03, 2004 6:46 pm
Posts: 13688
Location: ADL

I run 11.4:1
With 98 Octane fuel.
And a special cam :lol:

Top

drmini in aust

Post subject:

Posted: Wed Nov 07, 2007 9:05 pm

religious status

Joined: Fri Mar 19, 2004 6:19 pm
Posts: 39753
Location: near Baulkham Hills, NSW

willy wrote:

I run 11.4:1
With 98 Octane fuel.
And a special cam :lol:

And, I now know what cam it is.... :wink:

I've now got one too.

Chong, you aren't supposed to leave da fuel in da car for 3 months like you just did. It ain't 98 anymore, it's more like kero. :lol:

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R. :mrgreen:

Top

Lillee

Post subject:

Posted: Wed Nov 07, 2007 9:28 pm

1360cc

Joined: Tue Jun 01, 2004 3:41 pm
Posts: 6858
Location: Special Tuning Sydney

yeah as I said, bad fuel...

_________________
Lillee - 1969 Morris Mini K

Top

slinkey inc

Post subject:

Posted: Thu Nov 08, 2007 1:45 pm

1275cc

Joined: Wed Jun 14, 2006 9:45 pm
Posts: 4031
Location: Adelaide, SA

Sounds like a fun engine you building, Mini-Dunger.

_________________
1964 Morris 850, 1330 Supercharged - 81.8hp atws.
1975 Leyland Mini S 1100S powered - Nice and reliable.
1977 Leyland Mini LS - Project LS-T

Top

mini-dunger

Post subject:

Posted: Thu Nov 08, 2007 4:50 pm

1275cc

Joined: Thu Jun 08, 2006 9:34 pm
Posts: 2372
Location: Adelaide

Should be,

Everythings been lightened and made all nice so it should be nice.
Heres my head, I still have to press the guides in, smooth out the roof of the chamber and have the valve seats cut and about an inch milled of the deck.

excuse the paint I was using it as kind of a guide coat...its darkish in my shed

_________________

blokeinamoke wrote:

Yep Mokes are ugly - but Moke owners know that. Its like ugly women - she may be a dog but you know your going to get some :wink:

Top

Page 1 of 2

[ 17 posts ]

Go to page 1, 2 Next

Board index » Mini Chat » Mini & A/A+ Series Mods

All times are UTC + 10 hours

Who is online

Users browsing this forum: No registered users and 22 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

Jump to: