if you want tiwn 40's like people suggested, these are for sale from a friend. PM if interested, if you want a price and i'll give you his number

Ok I just went and hunted thru some books and found that an 1 1/4 can apparently flow at 110 cfm.

So provided the rest of my calcs are correct if you ran 2X1 1/4's you'd run out of steam at 5,674 RPM assuming you had 100% vol eff... so its probably more like 6200 or something (don't know just guessing it depends on the head, the compression, the cam, etc etc)...

But it wouldn't be much of a screamer,, soooooooo.... yeah. I'd start with the webbers for sure simon.
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Man I wish I had a flow bench and dyno...

EDIT: sorry clutch-monkey.. you snuk up on me, I'm such a slow typer nice looking set up there

not trying to shoot anyone down here, but to maximize the big wad of cash your going to spend on a 7 port head and twin Weber setup you wouldn't want to put it on anything less that a hot 1275. Anything else and your selling yourself short

1098's are fine for turbo and supercharger setups, mainly because if you break one its no big deal, and because forced induction has almost limitless power potential

Last i head Graham Russel was getting 170 odd HP out of Gregs race motor using a 5 port head.

A well set up 1275 with a 5 or 7 port head will give you lots of reliable power

assuming you dont have endless recources i would be inclined to spend my cash on a bored 1275 with a hot 5 port head, it will poo on any NA 1098

boring and proven i know, but i would hate to be the guy with a ten grand, 7 port, 1098 that gets owned by hot 1275s

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--Insert legal disclaimer here--

haha thanks, they are off a datsun.. the guy offered to make me a manifold so it would fit the mini, i just thought it was overkill for a standard/mild 1275 hahaha, sounds like this guy would get much better use out of them

willy is looking at selling his GR stroker, and that engine is going to flog any 1098cc this forum has ever seen.... Why not ask him how much he's looking foe to sell it? You could potentially save yourself a decent whack of money.

At the end of the day, for an uber hot 1099 you're going to want disc brakes anyway; you'd be silly not to go for for a 1275 if big power is your goal.

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"I'm sorry, but a lack of planning on your part does not constitute an emergency on my part!"

I couldn't agree more. I personally (now this is just my opinion) have never seen the point in chasing hp out of a small bore motor. After the intial purchase of the block and head, the price of hotting the two up is pretty close,, but the difference is that at the end of the day it is cheaper and easier to get more hp out of big bore motor than out of a small bore.... The money it costs to max out a small bore would build a frecking hot 1275 that would still produce more power.

But the question was on a 1098,,, so I assume (oh no not that word again ) that there is probably a good reason that Xamph doesn't want to go to a big bore motor...

I have a friend who has recently done a 1100 blown motor and he swears by it... He reckons it was cheaper for him to get the hp he did (110) by supercharging it rather than going thru building a hand grenade N/A motor... and he loves the way it pulls from right down low with out having to wait for it to come on the cam...

Me, I'd go the N/A route and I wouldn't be chasing 110hp, I'd be chasing maybe 80hp for a road car... My reason for that opinion is that I reckon you can get a more reliable 80hp than 110... And I'm not into blown motors,,, I don't know,,, the idea feels kinda dirty to me,, kinda like cheating.. But that just me... don't let what I think change your mind

The reason I chase horses out of small bores is that's what I've got, and it's cheaper to bolt go-fast bits on (or in) than to replace the whole thing

Plus, for me there's a challenge in it too. Anyone can get 60 HP out of a big bore, but it's a lot harder to do with a small bore

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Simon

The adventures of an owner builder in the Tallarook Ranges

Yes, but a 7 port head and twin webers is not exactly cheap.

7 port heads are around the $3k mark, regardless of which one of the 3 on the market you go for
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Twin 40mm Webers are around ~ $600 to $800 secondhand.
Then you prbably need to get them cleaned up, replace a couple of seals, get th eright jets and linkages.....
Cam to suit

You're at the $4k mark pretty quickly.

Supercharger setup would probably be cheaper (initially).

Still, pretty hard to beat the sound of a Weber.

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1970 Mini Deluxe - 1275, Weber, Clive 346 cam, MS 4-pot slotted discs, Megajolt ignition Now with new improved Mambas... almost on the road
1966 Van with Traveller rear seat conversion
2008 Prado GXL
All in various states of repair...

it's expensive yes, but buy it right, buy it once, if you knwo what i mean
besides, provides a goal to work towards

i paid $200 for the twin cam head that`s sitting ontop of my small bore 998cc engine

& i paid $120 for the quad 40mm bike carbs,,, then it was just 4 bits of bent exhaust pipe , 4 short bits of hose, 8x hose clamps & it was running,,, even used the std mini throttle cable easy-peasy



sorry,,, i don`t mean to hi-jack the thread,,, just threw that up there as a cost comparison

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

A good point though Matt, given that availability of your Twinky kits and the proven power output, not to mention a much smoother running engine. Add a blower on to that.........

You'd have to be a bit silly to spend $3000 on a 7port wouldn't you?

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"I'm sorry, but a lack of planning on your part does not constitute an emergency on my part!"

A fully installed Twinky kit will stretch into the thousands though, by the time you factor the head, carbs, Matt's kit, machining, etc. into the bargain. The 7-port is bolt-on-and-go..

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Simon

The adventures of an owner builder in the Tallarook Ranges

No it's not, because the manifold/s would have to change. The standard five port manifolds aren't going to fit

But then I suppose you're going to up for manifolds for the twinky kit too......or do the carbs from the bikes fit?

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"I'm sorry, but a lack of planning on your part does not constitute an emergency on my part!"

Nice quote,, puts a nice slant on what I was getting at and totally changes the context... Now really I should be mad,, But thats impressive

I did go on to say that he probably had a reason... Like the cost of the purchase motor in the first place

Nothing quiet like the fun and hard work of pushing sh1t up hill with a tooth pick... But I do have to say, I'm always very impressed when someone pulls up in a small bore that will thrash the pants off a standard (or warm) 1275. Good on you sgc

And I'm still waiting for an excuse to try out a set of those bike carbs... I reckon they sound mighty interesting

And almost " secret squirrel " there is a " square " 850 with 50hp that will now be getting a 544 cam and twin 1 1/2 SU,s , very Formula Junior.

( no its not mine , but you will know the car when it overtakes you ! )



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