crossflow 1100 to 1300
deep blue - 21/6/11 at 06:25 PM
I have an 1100 cross flow engine and a striped bottom end off a 1300gt both are 711ms.
I intended to fit the 1300 rods and perhaps the cam to the 1100 engine, gain a few ccs.
Then memory being fallible i got to thinking 25+ years ago my mates 1100 ex army estate was no slouch, and i just cant remember if there was a lot of
difference to my 1300 estate regarding torque and general drive ability day to day.
We both hated the small engines at that time and went straight for the 1600s to drag trailers and such like about a little better.
Now in a small light kit car with a low 4.7 to 1 final drive and standard 14inch tires. will the Difference going to 1300cc be still worth wile
bearing in mind i will be using this engine in a classic trials car. ultimate hp is handy but flexibility and trickle ability coupled with quick
response is probably more necessary.
Should i up the capacity as suggested above or put my effort in to a head mod/ cam and whatever to try and bring the 1100 in to line. my 1100 is
at the moment essentially a nice running if some what lack luster engine. Which way to go in your opinions?
And finally as for a 1600 this is not an option i want to consider with this project dispute the obvious potential advantages.
myke pocock - 21/6/11 at 07:22 PM
I have to say that if its the Marlin that the engine is going in then you MUST fit the 1300 at the very least and then do as much to it as possible
within your budget. I would be going for a mild road cam, 4 branch manifold, DGAV/DGV carb and do some smoothing out work on the head. All that
shouldnt cost you too much as you will, with a Marlin, be up against some serious engines. We have a club member who occasionally trials and
PCT's his 1380 Marlin that has twin Webers etc and it goes well in Class 0 Classic Trialling.
ianclark1275 - 21/6/11 at 07:29 PM
im using a 1300 with a gt cam, its quite low compression i think, but you cant beat extra cc's
but is the block hight the same on the 1100 ans 1300? you surely need crank and rods together if blocks the same?
nice to see your using classic power!
IC
deep blue - 21/6/11 at 09:08 PM
quote:
Originally posted by ianclark1275
im using a 1300 with a gt cam, its quite low compression i think, but you cant beat extra cc's
but is the block hight the same on the 1100 ans 1300? you surely need crank and rods together if blocks the same?
nice to see your using classic power!
IC
That is not how i understood it, the 1300 as longer con rods but the crank throw is apparently the same, In the normal 1300 the pistons have either
a larger bowl or are slightly taller from the gudgeon pin to the crow not had the head off this 1100 to see the difference . Put it this way a 1300
with 1100 pistons is supposed to give a compression ratio around 10.5 to 1. Now if the smaller piston bowl stifles any potential gain from the
increase in compression due to its reduced bowl size i could not hazard a guess, the more enlightened amongst us may know the answer to that.
myke pocock i hear where you are coming from with the get the cubic centimeters, my heart told me this initially. But i have no background to tinning
small fords like this and the capacity increase is not vast so i thought i would ask the question if anyone had ever bothered to tune 1100s to any
degree. .
spiderman - 21/6/11 at 09:25 PM
1100 stroke = 53.29mm
1300 stroke = 62.99mm
You will need 1300 crank to give increased capacity. The reason for longer 1100 conrod is to run the piston further up the bore to give a comp ratio
similar to the 1300 as the block heights are the same. May be able to run 1300 crank with 1100 con rods to give increased capacity and higher comp
ratio. Obviously need to make sure piston rings do not rise above block deck height also make sure that any ridge wear in the bore is removed to stop
the rings binding at increased height.
1100 con rods are longer than 1300 ones according to my haynes manual.
[Edited on 21/6/11 by spiderman]
[Edited on 21/6/11 by spiderman]
deep blue - 21/6/11 at 10:30 PM
quote:
Originally posted by spiderman
1100 stroke = 53.29mm
1300 stroke = 62.99mm
You will need 1300 crank to give increased capacity. The reason for longer 1100 conrod is to run the piston further up the bore to give a comp ratio
similar to the 1300 as the block heights are the same. May be able to run 1300 crank with 1100 con rods to give increased capacity and higher comp
ratio. Obviously need to make sure piston rings do not rise above block deck height also make sure that any ridge wear in the bore is removed to stop
the rings binding at increased height.
1100 con rods are longer than 1300 ones according to my haynes manual.
[Edited on 21/6/11 by spiderman]
[Edited on 21/6/11 by spiderman]
Thanks for that i do in fact have a 1300 crank as it happens the impression i got was it was the rods and pistons only to convert to 1300 from
1100.
It is in fact off the linked site below i got this info if i read it properly , if you look on the link below then the last line on the tinning
the 1100 paragraph gave me my assumptions i posted above. here is the link. http://www.locust.org.uk/knowlegebase/xflow/xflow.htm
[Edited on 21/6/11 by deep blue]
spiderman - 21/6/11 at 10:43 PM
cubic capacity is the swept volume of the piston.
bore x stroke = cubic capacity.
So with the same bore you need a longer throw on the crank the longer rods are just to keep the compression ratio at approx the same, roughly 9:1
unless its a low comp motor which is around 8:1.
u2u sent.
I,ve read the link you posted up and I can see why you beleived that rod and pistons increases capacity but they are wrong as you cannot change the
laws of physics.
[Edited on 21/6/11 by spiderman]
[Edited on 21/6/11 by spiderman]
deep blue - 11/11/11 at 06:20 PM
Just an update for those who replied to my post and of course anyone else interested. I fitted the 1100cc crossflow standard apart from a home made
single su adapter short term. And decided to rebuild the 1300GT modifying it a little cam manifolds carbs etc.
I checked the crank and got new shells and rings for the good std bores and pistons, cleaned everything in sight and tarted it up a little
aesthetically.
The gt cam was in ok condition but i noticed a cam on an auction site that was listed as an A1 profile
i looked for info on A1 profile but could
find nothing about it , so guessed if it was indeed a A1 it would probably be a shade hotter than a stock ford GT and May be what i need in a trials
car, So i took a gamble and purchased it, it looks different to the cam i took out of the 1300 so can only hazard it may well be a A1 but by no means
certain. Any advice or your thoughts on this aspect of my build i would be great full for help here.
I am now looking at modifications to the head and induction and exhaust manifold choices carbs etc. I have at my disposal several carb options i
am not too sure about which one to go for and again would appreciate any advice from those in the know on these choices, let me explain what carbs i
have. i have a pair of dellorto 40s i need a manifold for and jets but are good clean carbs .. I also have a set of complete Honda CBR 600 carbs
again in good condition and a steel plate profiled off the inlet manifold gasket of the 1300. Or last but perhaps not least use this plate and make a
twin su carb set up from one of two pairs of sus i have in my cupboard one set off a spitfire 1300 the others off an MGB.
Now i am open to sujestions here as to what arrangement you all may feel i would be best choosing, but please bear in mind the nature of the
beast i am trying to create, it will be running at odd angles up steep inclines on rough for want of a better word roads, and torque and flexibility
along with smooth running throughout the rev range is desirable.
And finally 1...heads, will a fiesta 1117cc cossflow head fit my old type 1300 711M block or are they different, i was trying to get a head off a
breaker that would run unleaded reliably without modifications.
And 2... what mods should i do to my eventual head to improve practical performance.
PHEW! sorry i never realised i had so much i needed answers to. Thanks in anticipation .
D Beddows - 11/11/11 at 06:39 PM
1100 rods in the 1300 block and a set of lotus twin cam pistons would have been the way to go 
add a 224 cam, a 1600 GT head and a set of twin
40's and you've got a decent budget crossflow screamer that would sound awesome! - it was a serious engine conender when I was still
building a kit car, I had all the bits apart from the 1100 con rods which I never managed t get hold of for one reason or another.....
[Edited on 11/11/11 by D Beddows]
britishtrident - 11/11/11 at 07:00 PM
Sorry guys but time for reality pills
The facts are
You need 1300 crank and 1300 rods to give 1300cc.
1100 pistons in a 1300 engine will raise the compression ratio but it won't change the cubic capacity.
But for the piston rings to survive the bores will need properly honed to get rid of the ridge at the top of the bore and glaze busted to create
a surface rough enough to retain an oil film and let the rings bed into
deep blue - 11/11/11 at 07:48 PM
Thsnks for the replies folks, and i apologize for this but the 1100 to 1300 original question is all sorted out now, If you look at the link to the
locost engine build page and read that info it was indeed wrong and states just rods if you look.
Spider sussed this and indeed saw exactly how i had been mislead by info on that page. So again sorry, ignore my original request, but please
please comment on my last post on my 1300 rebuild there lays info i really do need help with thanks again.
deep blue - 11/11/11 at 07:54 PM
quote:
Originally posted by D Beddows
1100 rods in the 1300 block and a set of lotus twin cam pistons would have been the way to go add a 224 cam, a 1600 GT head and a set of twin
40's and you've got a decent budget crossflow screamer that would sound awesome! - it was a serious engine conender when I was still
building a kit car, I had all the bits apart from the 1100 con rods which I never managed t get hold of for one reason or another.....
[Edited on 11/11/11 by D Beddows]
Can you elaborate in much more detail on this twin cam 1100 rodded engine, for example exact components needed what head etc to achieve your idea, or
any links to any further info on this conversion/ build.
Confused but excited. - 11/11/11 at 08:51 PM
quote:
Originally posted by deep blue
quote:
Originally posted by D Beddows
1100 rods in the 1300 block and a set of lotus twin cam pistons would have been the way to go add a 224 cam, a 1600 GT head and a set of twin
40's and you've got a decent budget crossflow screamer that would sound awesome! - it was a serious engine conender when I was still
building a kit car, I had all the bits apart from the 1100 con rods which I never managed t get hold of for one reason or another.....
[Edited on 11/11/11 by D Beddows]
Can you elaborate in much more detail on this twin cam 1100 rodded engine, for example exact components needed what head etc to achieve your idea, or
any links to any further info on this conversion/ build.
Mr. beddows did not say "twin cam 1100 rodded engine". He said use the pistons from a twin cam engine together with 1100 rods.
All the info you need is in this thread.
Hmmm, got a 1300/711, a big valve head, Kent fast road cam, GSXR TBs but never though of fitting 1100 rods.
Dear Santa. . . .
Mike Wood - 30/8/19 at 05:51 AM
Hi
If I wanted to convert a 1300cc Crossflow to 1100cc engine, how would I do it please? (1100cc pistons and rods plus a rehone of the cylinder bores to
remove the step? or would I need a 1100cc crank too?) I am just musing on how I could make my new 1300cc project hillclimb car into a budget Sports
Libre car for under 1100cc (1100cc and over Sports Libre now needs a National A licence, under 1100cc just needs a Non-Race National B licence); the
other way to go would be IVA to run in road car classes and then engine size is not a licence issue.
And when we say '1100cc' Crossflow, is that under or over 1100cc and what on overbores? Does an 1100cc Kent Crossflow have 1,117cc as
standard, so I would need to work with 997cc bits to build a sub 1100cc Crossflow?
Thanks
Mike
[Edited on 30/8/19 by Mike Wood]
[Edited on 30/8/19 by Mike Wood]
[Edited on 30/8/19 by Mike Wood]
[Edited on 30/8/19 by Mike Wood]
Memphis - 31/8/19 at 04:28 PM
quote:
Originally posted by Mike Wood
Hi
If I wanted to convert a 1300cc Crossflow to 1100cc engine, how would I do it please? (1100cc pistons and rods plus a rehone of the cylinder bores to
remove the step? or would I need a 1100cc crank too?) I am just musing on how I could make my new 1300cc project hillclimb car into a budget Sports
Libre car for under 1100cc (1100cc and over Sports Libre now needs a National A licence, under 1100cc just needs a Non-Race National B licence); the
other way to go would be IVA to run in road car classes and then engine size is not a licence issue.
And when we say '1100cc' Crossflow, is that under or over 1100cc and what on overbores? Does an 1100cc Kent Crossflow have 1,117cc as
standard, so I would need to work with 997cc bits to build a sub 1100cc Crossflow?
Thanks
Mike
[Edited on 30/8/19 by Mike Wood]
[Edited on 30/8/19 by Mike Wood]
[Edited on 30/8/19 by Mike Wood]
[Edited on 30/8/19 by Mike Wood]
I've just had to re-register as I forgot my login details, but have posted on here many times.
Unfortunately there is no such thing as "budget" motorsport these days; just expensive and less expensive!
To build a competitive 1100 Sports Libre crossflow engine will cost you thousands! To make any power from such a small capacity needs revs revs and
more revs! (Upward of 10,000rpm). It would require forged steel rods, forged pistons, an extremely well ported big valve head with lightweight rockers
and titanium caps etc. A standard 1100 crankshaft would probably be OK at such a short stroke. And then you'd need a very close ratio 5 speed
gearbox (preferably 6speed) to get it to the very low ratio rear axle. It all costs a lot of money. And you'd still end up being trounced by the
bike engined cars weighing 100kg less.
So, if you can't beat them; join them! Forget about the crossflow and put a sub-1100cc motorcycle engine in it. For the cost of a decent gearbox
you can install a modern bike engine with 180+bhp as standard, which (with a baffled sump), will reliably produce that power all day long, all season
long.
But you don't need to go into Sports Libre. Most championships now run a class 3 for modified kit cars. You can run virtually anything you like,
on slicks, and don't need to be road-legal (although you will need an RAC MSA passport or whatever it's called these days). This is the
class for the bike engined kitcars. You could run a crossflow; but it would be hopelessly uncompetitive unless it was a megabucks all steel 1800. It
just doesn't make sense to go down that route. Being comprehensively beaten is no fun at all.
Many years ago I stuck a GSXR1100WP Sidecar GP engine into a hillclimb/sprint Mallock clubmans car. It was an absolute missile; quite a bit faster
than with the all steel 1700 XFlow that was previously in there. It's the way to go.