More performance for Alpine Fastback?

[RootesRacer]

Are there any issues using the 2bbl intake with the engine canted?

Not if you cut the wedges from the 4 runners and re-weld like I said.

I'm not sure if hunters ever came with the 2bbl intakes with the angle already correct for the angled engine. I know of twin DCOE (alla H120) and twin stromberg CD150 intakes for the alloy head hunter. Lynx down in australia probably had some other nice options for that configuration as aftermarket.

 

[65beam]

fastback

one thing about the strombergs that came on the GT's here in the U.S. is that the intake manifold boted on top of the exhaust manifold . it has a copper gasket to seal the two and picks up heat for the fuel mixture . on my red car years ago i switched to a set of carbs off of a series 5 and used the GT intake . never could get them to run right . went back to the emission carbs after awhile . that was twenty years ago and since it was my everyday car ,i didn't want the problems .

 

[alpine_64]

Not if you cut the wedges from the 4 runners and re-weld like I said.

I'm not sure if hunters ever came with the 2bbl intakes with the angle already correct for the angled engine. I know of twin DCOE (alla H120) and twin stromberg CD150 intakes for the alloy head hunter. Lynx down in australia probably had some other nice options for that configuration as aftermarket.

Lynx did a single DCOE manifold for the hunter/arrow range. They are easier to get than the upright version here these days.

 

[RootesRooter]

Has anyone ever verified that late Series V and Arrow Range aluminum heads are identical? The manuals rate the fastback's 1725 several hp lower than the Series V. The reason may be that fastback heads have narrower intake ports than Series V heads - at least the early ones.

As far as the cast-iron headed version goes: a Tiger owner whose father used to own a Rootes dealership up in B.C. (Canada) said that Rootes-powered cars used to come back to the service dept a little too regularly for their liking. The exceptions were the cast-iron head 1725's in the Alpine Coupe and Arrow. Five mains and not so much heat made for durability.

Another hp bump might be to track down a set of twin carbs (Zeniths?) and manifold from an early, cast-iron head Rapier.

BTW, does your locality have any smog laws that a '69 might have to pass? The CDSE Strombergs barely passed the federal laws then in effect.

 

[V6 JOSE]

If you are thinking of using a V8, Why not use a Ford SB? It would be a lot easier and cheaper to source and buy. It will produce a lot more power and be easier to install. Everything to facilitate the conversion would be a lot easier to source too. A T5 transmission would be a perfect choice to complete the package too. Would make a great car.

The only reason to go with the the Rover V8, would be to have a Brit engine in a Brit car. If you were to go with the Buick version of that engine, (More available here) you would have even less power than the Rover version. A lot of work for not much benefit, IMHO.

Jose

 

[alpinefastback]

BTW, does your locality have any smog laws that a '69 might have to pass? The CDSE Strombergs barely passed the federal laws then in effect.

If the car is registered as a classic no emissions to pass.

 

[alpinefastback]

The only reason to go with the the Rover V8, would be to have a Brit engine in a Brit car. If you were to go with the Buick version of that engine, (More available here) you would have even less power than the Rover version. A lot of work for not much benefit, IMHO.

The Rover V8 is on average 100lbs lighter than the Ford SB. That's the reason I prefer it.
These cars were known as understeerers from the factory, so adding more weight to the front could make the car a really ill handler.

 

[RootesRacer]

Has anyone ever verified that late Series V and Arrow Range aluminum heads are identical?

Another hp bump might be to track down a set of twin carbs (Zeniths?) and

Yes they are undoubtedly the same head, difference being the cam.

I happen to have a an intake, exhaust and carbs for that motor, it was an SIII rapier IIRC.

Uses the 36WIP carbs like on the early alpine, but intake for the cast iron head.

 

[65beam]

fastback

keep in mind that to use other carb setups on these fastbacks may require a bulge in the hood due to clearance problems . there isn't much room between the hood and the front stromberg on a dual carb setup . it's real close !

 

[rootesrefuge]

Here's the intake and carbs. fresh off eBay Australia - item # 180329306378 .

Tempted to bid myself, but I only need carbs not the manifold. You'll still need an exhaust manifold, since the ports on yours won't match the alloy head. Oh, and I have a spare stock air cleaner assembly if you need one.

Jon Arzt
Omaha, NE USA

 

[alpinefastback]

Here's the intake and carbs. fresh off eBay Australia - item # 180329306378 . Tempted to bid myself, but I only need carbs not the manifold. You'll still need an exhaust manifold, since the ports on yours won't match the alloy head. Oh, and I have a spare stock air cleaner assembly if you need one.

Thanks for the info. I'm waiting to buy any engine parts until I'm sure which way I want to go.

 

[alpinefastback]

Mazda Miata 1.6 driveline

After considering many different ways to go about getting more performance from my Alpine fastback, the solution I like the best is an engine/trans from a Mazda Miata.

Here's why:
1. Inline 4, so it's the same form factor as the Sunbeam engine
2. Trans ratios match up perfectly with stock Sunbeam rear axle (although I will eventually get the rearend rebuilt with the 3.70 ring and pinion)
3. Should be about 40 lbs lighter than stock drivetrain based on internet research. So handling should improve.
4. 120hp, so about the same as an H120
5. Huge parts and aftermarket support
6. Add a turbo or supercharger and get an easy 150hp
7. 30mpg
8. Get a 5 speed with overdrive in the deal.
9. The cam covers look a bit like a Lotus twin cam engine, so it's actually reasonably attractive looking for a modern engine.

I'm curious what other thing about going this route.
I'm not looking to build a monster, just a balanced package that is fun to drive, economical and reliable.
I think anything more than 150hp in this car is kind of pointless since upgrading the suspension and brakes would require some serious re-engineering.

 

[RootesRacer]

After considering many different ways to go about getting more performance from my Alpine fastback, the solution I like the best is an engine/trans from a Mazda Miata.

Here's why:
1. Inline 4, so it's the same form factor as the Sunbeam engine
2. Trans ratios match up perfectly with stock Sunbeam rear axle (although I will eventually get the rearend rebuilt with the 3.70 ring and pinion)
3. Should be about 40 lbs lighter than stock drivetrain based on internet research. So handling should improve.
4. 120hp, so about the same as an H120
5. Huge parts and aftermarket support
6. Add a turbo or supercharger and get an easy 150hp
7. 30mpg
8. Get a 5 speed with overdrive in the deal.
9. The cam covers look a bit like a Lotus twin cam engine, so it's actually reasonably attractive looking for a modern engine.

I'm curious what other thing about going this route.
I'm not looking to build a monster, just a balanced package that is fun to drive, economical and reliable.
I think anything more than 150hp in this car is kind of pointless since upgrading the suspension and brakes would require some serious re-engineering.

First of all let me tell you the "H120" engine was actually 105 BHP.
Perhaps the plan was to make 120, but the holbay camming is for down low power, power is all done before 120 BHP is made. If all you want is 120 BHP then all you want from the holbay is the intake and its carbs (to put your own chokes and jets in).

Based on your criteria, Brian Holm (of this board) has done what you desire and then some.
He has taken a 1725 engine, fuel injected and turboed it, added a T5 5 speed and is very well beyond 150 BHP (if he would only dyno it).

There is a lot of potential in a 1725 engine, dont let anyone fool you.

 

[alpinefastback]

First of all let me tell you the "H120" engine was actually 105 BHP. Based on your criteria, Brian Holm (of this board) has done what you desire and then some. He has taken a 1725 engine, fuel injected and turboed it, added a T5 5 speed and is very well beyond 150 BHP (if he would only dyno it).

There is a lot of potential in a 1725 engine, dont let anyone fool you.

I don't doubt that I could get 120hp out of the 1725 engine.
But as far as I can see, the only thing tuning the existing 1725 engine has going for it over a Miata engine swap, is that it's more original.

For me, fuel economy, low emissions and easy to find spares outweigh originality.

The only thing that would prevent me from using the miata engine is if it requires major surgery to fit (which I need to do more research on.)

I also like that I get a 5 speed trans with the Miata and with a bolt on turbo kit can get 30 more hp without a lot of head scratching.

A low mileage 1.6 engine and trans are about $700, so it's cheap to boot.

If you think this swap doesn't make sense, for reasons other than originality, please tell me why.
Thank you for taking the time to post in my thread because I want different opinions to make an informed decision.

 

[RootesRacer]

Well it is your car but just about any engine swap will require you to do surgery, particularly to the trans tunnel. In the end the mods you do are permanent, its tough to undo an engine swap.

 

[RootesRich]

The Miata 1.6L conversion would be interesting to see but if it was my car, I'd swap the head to a SV, bolt on a modified S3/ IV intake with a Weber 38/38, get a Delta KB ground SV cam, lighten the flywheel and finish it off with a set of headers.

I would think all the upgrades could be had and modified for less than $1K (with some savvy eBay shopping) and take a weekend to install. Nice performance upgrade and good fuel economy.

No matter what direction you decide, you've got my encouragement.

 

[Jim E]

Or you copuld put a rotary in it

 

[alpinefastback]

No matter what direction you decide, you've got my encouragement.

Thanks, I'll keep the board updated when I make my decision.

 

[alpinefastback]

Or you copuld put a rotary in it

Rotary was one of the initial 3 engines I was considering:
Mazda Rotary
Ford 2.8 V6
Rover V8.

Then I read more about:
GM 60º V6
Mazda Miata

Good things about the rotary:
Easy mods for more HP.
Really compact and lightweight.
Smooth idle.

Bad things about the rotary:
Read that Tiger Tom did this conversion and had to modify steering to get it to fit.
Not very fuel efficient to start with and easy to make a gas hog with performance mods.

I haven't ruled the rotary out, but the Miata engine looks like it will drop in with very little surgery. Motor mounts are close to same location as Sunbeam engine.

 

[rootesrefuge]

Or you could do what I've been thinking about for my wagon.

The Talbot Sunbeam Lotus used a 2.2 liter Lotus engine, good enough in works trim to win the 1981 World Rally Championship. That same basic engine was also used in the Jensen Healey. The Jensen Healey happened to use a Rapier gearbox. So it shouldn't be too difficult to put a Jensen Healey engine into an Arrow range car, whether it be an Alpine, Rapier, or Hunter. I've heard of one swap in the UK, but haven't found any pictures.

But it sounds like fun!