AJWatUC
4 posts
Joined: 29/10/2006 01:20:41
Location: Cincinnati OH United States
Will a 1.3 intake manifold with dual Carbs fit my 998cc
I have a 1976 Austin mini with a 998cc engine thanks for any feedback
Posted: Oct 29, 2006 01:58 AM
C. Barron
332 posts
Joined: 04/05/2006 21:28:31
Location: Mid Calder United Kingdom (Excluding channel Islands)
Fit, yes. Work, probably not without being set up properly.
A 998 would never need more than twin 1.5 su's, so if your 1300 manifold has twin 1.75's it would be more trouble than it's worth.
Assuming you've got twin 1.5's or 1.25's your only other outlay will be a new gasket, a apir of needles and possibly new dashpot springs. there's plenty of information in the Calvers corner articles to give you 'ballpark' needle selections but you'll never be sure to have the right needle without putting the car on a rolling road.
Chris
Posted: Oct 29, 2006 01:28 PM
thanks for the info. I'm not going to get it
Posted: Oct 29, 2006 03:13 PM
A standard 998 will run well on a single 1.5", when you consider that most factory 1275's also got a 1.5" carb as standard it's easy to see why.....
Posted: Oct 29, 2006 06:40 PM
John
1948 posts
Joined: 28/05/2006 16:49:46
Location: cambridge United Kingdom (Excluding channel Islands)
non cooper 1275 90's intake valve size?
do 1990's minis 1275's all have 1.4" intake valves as it says in hains manual or is it a mistake?
Posted: Feb 10, 2007 11:14 PM
Luke6040
210 posts
Joined: 17/11/2005 17:00:38
Location: Wolverhampton United Kingdom (Excluding channel Islands)
Hey
Iv bin having a good read trew my books and it looks like only the MG!300, 1300GT, and all 's' engines had the 1.4, if youv got a 1275 austin/morris, 1275 sprite, or 1275 mini GT its the 1 5/16" inlet.
Luke
Posted: Feb 10, 2007 11:53 PM
if its a series vizard book i know it doesnt show anything but 1300 gt and cooper s and mg metro with 1.4" valves. but that was first published in 80's and doesnt mention 90's 1275's anywhere in book.
Posted: Feb 11, 2007 12:20 AM
have you got the casting number, and i can tell you from that. cuz vizards book is a bit confusing with the sizes
Posted: Feb 11, 2007 05:58 PM
T. Perks
57 posts
Joined: 19/11/2006 09:21:16
Location: Wotton under Edge United Kingdom (Excluding channel Islands)
std 1275 inlet size was just atad over 33mm, whereas mg metro inlet valve is 35.7mm or 1.4", all ex were 29mm all with 9/32" stem except mg metro turbo which i think was 8mm and sodium filled.
Posted: Feb 11, 2007 08:54 PM
chears just bourt myself mg metro head :-) they dont have hardened valve seats do they?
Posted: Feb 11, 2007 11:09 PM
depends on the year i think it was 1989/90 when all heads came with hardened seats. What sort of mileage do yo do, as most seats seam to live fairly well with unleaded fuel not showing signs of recessing until probably a good 30-40000, course you dont really know the history of the head do you?.
Posted: Feb 12, 2007 11:22 AM
no dont know history, i do around 7k a year maybe more so il get hardened seats fitted and new valve guides il port it as well, not sure weather to go for bronze or cast iron. differnt people seem to have differnt views on life expectancy of both. in vizards a series he say bronze if hard alloy lasts better, but on here they recomend cast ones.
Posted: Feb 12, 2007 01:15 PM
if youre only doing 7k then i wouldnt bother using hard seats, in my rally car i dont use them and im sure it gets a harder thrasing than any road car, i also dont use any additives just the best shell optimax type stuff, as for guides use std iron guides for std valves and use alloy bronze for stainless valves, again on my mini i use bronze on the inlet and iron for the exhaust and no stem seal.
Posted: Feb 12, 2007 01:59 PM
yeah il still get inserts as will do high mileage eventually dont wanna have to strip it down in 5 years and have valves recessed into the head espeshally after thinning the seats slight while porting it. yeah i think il use cast iron valves guides with caps on intakes. you dont know if mg metro uses uprated springs do u?
Posted: Feb 12, 2007 04:15 PM
Not sure about the springs ive never measured poundage on any spose i'll get round to it eventually, remember to use the right springs though if the head is a n early flat type 12G940 then use the springs to fit that as they are different height to the newer 12G940 with the sculpted top face. But either will be fine with a std cam up to about 6500rpm, a little more if you have 1.5 rockers fitted.
Posted: Feb 13, 2007 01:09 PM
Iain
44 posts
Joined: 29/02/2008 12:23:18
Location: Aberdeen United Kingdom (Excluding channel Islands)
Removing heater air intake
Trying to remove the heater fresh air intake so I can replace the clutch, but find I can't remove the intake.
My car has the short section which turns thru' 90 degrees into the driver side wing before connecting to a length of flexible hose. I can't see any fixings after removing the flexible duct and don't want to use brute force in case I break the duct.
Any help please, thanks.
Posted: Mar 24, 2008 07:16 PM
minial
2 posts
Joined: 28/08/2006 14:00:08
Location: Peterborough United Kingdom (Excluding channel Islands)
hi
I'm just trying to reassemble the same parts.
the intake is just a tight push fit through the inner wing, its just a case of applied brute force to remove it.
i hope you can assist me, is there an elbow on this fitting where the flexible hose connects, its been so long since i dismantled it i can't work out how it goes back together. The flexible hose seems too stiff to bend through 90º and connect to the distributor box under the wing.
Posted: Mar 24, 2008 07:48 PM
Thanks for the advice, I wasn't sure if brute strength is all it needed.
On my car there is no 90 deg bend section inside the wing, the flexible duct turns thru' 90 deg at the end to attach to the spigot protruding through.
I know what you mean by the "flexible" duct being really stiff, but it does turn sharply through 90 degrees.
Posted: Mar 25, 2008 05:59 PM
Dutchy
10 posts
Joined: 16/03/2010 22:29:22
Location: Bentleigh East Australia
1994 SPI intake manifold modification
Does anyone know what will happen if i remove the deflectors inside each side of the manifold? i am thinking that they deflect the air & fuel a bit more evenly between the inner & outer cylinders.
Posted: Aug 18, 2010 08:25 AM
unclegee
1 posts
Joined: 06/10/2017 00:51:50
Location: Moscow United States
Mini Spares Intake Manifold
I have a 1988 Mini Mayfair fitted with stage I kit. I recently moved my little gem 12500 original miles from the US mainland to my home in Hawaii. I have never bothered to hook up heated manifold. Now that I'm in an extremely wet humid climate, I'm getting a misfire at highway speeds on very humid days. I attribute this to carb iceing. What is the correct routing of coolant hoses to the manifold. Seems everyone on the forum has an opinion no 2 the same. As a long time pilot, I can say with certainty, you can get carb ice on a 90 degree day as easy as a set 40 degree day. So in my case want heat all the time, not just when the heater valve is open.
Posted: Jun 03, 2020 07:13 PM