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minormadmaniac Avatar
minormadmaniac Jacob Vipperman
Christchurch, New Zealand   NZL
So I want to make a Minor go fast (80-100 hp would be nice) without swapping engine. The first and obvious thing to do is to remove weight, and then to upgrade/stiffen the suspension to go faster through corners. But what can I do to the engine to make more power reliably? An engine needs four things: air, fuel, compression and spark. So more displacement increases the amount of air the engine can take in, a bigger carburetor allows more fuel into the engine, domed pistons or flycutting the head increases compression, and a full digital ignition system would give a stronger spark and a cleaner burn. What else is there to do? What's the biggest stroke and bore I can run safely before I start running into cylinder wall warping and other issues? Obviously I'll be going with forged internals. I'll probably be going with a small 948cc or so engine, and I'll be strengthening the drivetrain to suit.



Edited 2 time(s). Last edit at 2018-04-14 06:16 PM by minormadmaniac.

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minimarc Avatar
minimarc Bob Marcum
BREVARD, NC, USA   USA
I suggest you get a copy of David Vizard's book: Tuning an A Series Engine.

Good Luck on your effort.



Bob Marcum

1959 Bugeye
1960 Morris Minor Tourer
Ex vintage Mini racer

emjay Jim English
Marietta, PA, USA   USA
I second Vizard's book to get the top reference for many different engine mods. Beware there is a difference between race car power and streetable power. Of course there is a limit to carbs and distributors. Today's engine controls manage to get even more power out each year. You might want to look into fuel injection and electronic mapping of the ignition. There's quite a bit available for the B Series engine. There is some starting on the A series, but typically not for 948. The 948 is best suited for higher rpm due to the shorter stroke and a common mod is to bore it out to 998 or so to use 1098 pistons and rods.

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minormadmaniac Avatar
minormadmaniac Jacob Vipperman
Christchurch, New Zealand   NZL
I'm not really going for EFI, I like everything mechanical and want to keep it old school. I understand electronic everything is more precise, but it's just not as cool.

In reply to # 29515 by emjay I second Vizard's book to get the top reference for many different engine mods. Beware there is a difference between race car power and streetable power. Of course there is a limit to carbs and distributors. Today's engine controls manage to get even more power out each year. You might want to look into fuel injection and electronic mapping of the ignition. There's quite a bit available for the B Series engine. There is some starting on the A series, but typically not for 948. The 948 is best suited for higher rpm due to the shorter stroke and a common mod is to bore it out to 998 or so to use 1098 pistons and rods.

3mikey mike mitchell
Milwaukee, WI, USA   USA
If you're going to have a stout lower end why not go with a turbo . . More boost = more power.

0123 Mike D
Biddulph, Staffs, UK   GBR
In reply to # 29508 by minormadmaniac So I want to make a Minor go fast (80-100 hp would be nice) without swapping engine. The first and obvious thing to do is to remove weight, and then to upgrade/stiffen the suspension to go faster through corners. But what can I do to the engine to make more power reliably? An engine needs four things: air, fuel, compression and spark. So more displacement increases the amount of air the engine can take in, a bigger carburetor allows more fuel into the engine, domed pistons or flycutting the head increases compression, and a full digital ignition system would give a stronger spark and a cleaner burn. What else is there to do?

Powerful brakes
What's the biggest stroke and bore I can run safely before I start running into cylinder wall warping and other issues? Obviously I'll be going with forged internals. I'll probably be going with a small 948cc or so engine, and I'll be strengthening the drivetrain to suit.

pixelsmithusa Avatar
You won't get 80 to 100 HP out of a 948 without spending a great deal of money. Even then, you'll be stretching the engine to its absolute limits. At the very least you should start with a 1275, as it's a direct bolt-in swap. In stock form, the 1275 is almost double the HP and torque of a 948 and you have a much stronger crank with 2" journals. You'll get your greatest gains with a ported head, going to a single 1.5" (HS4) or 1.75" (HS6 or HIF44) carb and a tuned exhaust with long branch header. An MGB engine has only 15 more HP than a 1275, and most of that gain is going to be lost in the additional weight you'll add to the car. It's not a good swap. If you want to do a non-original engine swap, the Datsun A15 is also 75-80 HP, but greater torque still. It fits without a lot of modification, commonly available with a matched 5 speed, has an aluminum head and a 5 main crank. Another popular swap and well fitting engine is the Fiat Twincam. This is a hugely popular swap in the UK. The Fiat twincam pictured below develops 130 HP, and is also has a 5 speed gearbox.

A V8 Swap is going to require you to fabricate a custom chassis or modify one from an existing vehicle that will need to be shortened and narrowed to fit under the Morris. Many people have used the Chevy S10 chassis to make the swap, but it's a very extensive project that will require a long-term commitment and lots of $$ to complete.



Gerard

http://gerardsgarage.com/



Edited 1 time(s). Last edit at 2018-04-21 01:45 AM by pixelsmithusa.

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0123 Mike D
Biddulph, Staffs, UK   GBR
He'll learn more faster his way Gerard

thumbs up



Edited 1 time(s). Last edit at 2018-04-22 03:16 AM by 0123.

emjay Jim English
Marietta, PA, USA   USA
A nice short V-8. We need someone like Henry Ford to graph two A Series blocks together, a sweet 1896cc V-8 with slender rods and a whooping 74hp. Now that would be a novelty.

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