More performance for Alpine Fastback?

[alpinefastback]

As I have posted in the General Chit-Chat section, I am the new owner of a 1970 Sunbeam Alpine fastback.
From all the British articles I've read about these cars, I was expecting that my car had an aluminum head, even though it had a single carb.
I've since learned that for the North American market the base model Alpine got the same 1725cc engine block, but to save costs, it got an iron head.

So my question is, what can I do to get more hp from this engine?
I've read that the dual carb manifold from a Alpine GT won't work on my car because the #2 & #3 intake and exhaust ports are reversed.

Would one of the Weber DGV carb/manifold setups work on my car?
http://cgi.ebay.com/ebaymotors/New-Sunbeam-Alpine-Weber-32-36-DGV-Carb-Kit-and-Filter_W0QQitemZ250311845862QQihZ015QQcategoryZ10076QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Are there other cams available for the iron head engine?
If carbs and cam are available for this engine, is it worth the cost, or should I just try to find an Alpine GT (Rapier) aluminum head and factory dual carbs?

I know engine swaps are a touchy subject around here, but finding the parts to keep my car all Sunbeam might prove to be difficult, so I'm open to ideas for an engine swap as well.
I've read from this thread:
http://www.sunbeamalpine.org/forum/showthread.php?p=62349&highlight=rotary#post62349
that the Ford 2.8 V6 and Mazda rotary have been swapped into these cars, but both require mods to clear the steering.
Any thoughts on a Rover v8? All of these engines are around 300lbs, so they shouldn't alter the handling too much.
I've looked under the car and see how the drag link is the problem.
Creating a lowered drag link and possibly modifying the sump would probably solve the problem. Is there anything else I'm missing?

Thanks for your replies,
Jeff

 

[Chuck Ingram]

As I have posted in the General Chit-Chat section, I am the new owner of a 1970 Sunbeam Alpine fastback.
From all the British articles I've read about these cars, I was expecting that my car had an aluminum head, even though it had a single carb.
I've since learned that for the North American market the base model Alpine got the same 1725cc engine block, but to save costs, it got an iron head.

So my question is, what can I do to get more hp from this engine?
I've read that the dual carb manifold from a Alpine GT won't work on my car because the #2 & #3 intake and exhaust ports are reversed.

Would one of the Weber DGV carb/manifold setups work on my car?
http://cgi.ebay.com/ebaymotors/New-Sunbeam-Alpine-Weber-32-36-DGV-Carb-Kit-and-Filter_W0QQitemZ250311845862QQihZ015QQcategoryZ10076QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Are there other cams available for the iron head engine?
If carbs and cam are available for this engine, is it worth the cost, or should I just try to find an Alpine GT (Rapier) aluminum head and factory dual carbs?

I know engine swaps are a touchy subject around here, but finding the parts to keep my car all Sunbeam might prove to be difficult, so I'm open to ideas for an engine swap as well.
I've read from this thread:
http://www.sunbeamalpine.org/forum/showthread.php?p=62349&highlight=rotary#post62349
that the Ford 2.8 V6 and Mazda rotary have been swapped into these cars, but both require mods to clear the steering.
Any thoughts on a Rover v8? All of these engines are around 300lbs, so they shouldn't alter the handling too much.
I've looked under the car and see how the drag link is the problem.
Creating a lowered drag link and possibly modifying the sump would probably solve the problem. Is there anything else I'm missing?

Thanks for your replies,
Jeff

Jeff
If I remember rightly (it was a long time ago) the 2.8 fits quite easily in the fast back engine compartment.Motor mounts I made up and using the ford /capri donuts it was not hard.I modified the tranny mount to fit.A ford drive shaft was found and of all the luck it was the right length and as we had fitted the 8 inch Ford rear end so how easy can it get.
You are right about the steering arm.we made /modified a drop link to clear.
We never modified the sump.Due to finishing school and getting married he let he car sit.we finally parted it out after the rust took over.It was a fun car and seating for four was an asset.I do think a Rover V8 would be a good swap as it is basically a buick engine and there are performance parts available.
But then as I'm partial to the 302 i think I would go that route.Being me I would build another front end as I have just done.And of course a Ford 8 inch rear You probably can use front wheel drive wheels and you may not need to do any work for clearance
as I mentioned it was about25 years ago so yes it is a long time to try and remember
Remember to enjoy the journey
Chuck

 

[alpinefastback]

Chuck,

Thanks for the reply. the 2.8 V6 seems like it would be a good way to go since it seems for you it dropped in without too much fuss.
Ideally I'd rather keep it stock, but if I can't get adeqaute performance from the Sunbeam engine, a swap might be ideal.
If I choose to swap a motor in I want to make sure it's one I won't regret. The Rover V8 is appealing because well it's a V8 and an Alpine Fastback with a V8 rumble would be undeniably cool.
I like the 302, I had a 68 Mercury convertible (now my father's) with one, but don't you think it would be a bit heavy for the Alpine?

When you said you built another front end?
You created new front suspension and steering under the 302?

Thanks
Jeff

 

[65beam]

fastback performance

keep in mind where the front axle and center line of the front wheels is . i had this discussion with tiger tom several years ago. he found it very hard to install any other motor without making the car dangerous to drive due to position of the axle setting at the back of the alpine motor. yes, chuck installed the other motor ,but after many years of the quirky steering and handling of these cars,it would scare me . there is only one adjustment to the steering and that is toe in . so be careful what you change .

 

[alpinefastback]

keep in mind where the front axle and center line of the front wheels is . i had this discussion with tiger tom several years ago. he found it very hard to install any other motor without making the car dangerous to drive due to position of the axle setting at the back of the alpine motor. yes, chuck installed the other motor ,but after many years of the quirky steering and handling of these cars,it would scare me . there is only one adjustment to the steering and that is toe in . so be careful what you change .

I'm not sure I understand. The issue is that fitting a different motor tends to put too much weight ahead of the front axle?
When you say the "position of the axle setting at the back of the motor" are you talking about the drag link?

I agree that this isn't the best handling car.
The steering seems to quicken the closer you get to full lock.
Tiger Tom went with a Mazda rotary in his car, correct?

 

[65beam]

fastback

take a look at the fastback versus the alpine . you will find that the motor mounts on the fastback are on the side of the motor and not at the front of the motor . the actual frame points for the mounts set forward of the axle ,moving the motor farther ahead . the bellhousing of the fastback actually sets in front of the firewall compared to the alpine plus chrysler had to make a longer bellhousing and longer input and out put shafts for the trans . tom spent many hours checking demensions of motors and weight distribution prior to installing the rotary . he also had to go with a rack for steering along with other modifications . he and i discussed the installation of a V6 and he advised against it . weight distribution is a problem with these cars if you start modifications plus take a look at the front suspension . there isn't much there . the steering doesn't get tighter, the wheels are changing planes is my best way to describe the steering . look at the angle of the front struts . almost vertical. i have found the cars to be quite nice the way they are since i can run the speed limit anywhere i go . of course speed and more power doesn't mean anything to me . i never get in a hurry . if you want a better running 1725 , throw away the cast iron head ,cam,and the carb . install an alloy head and matching cam, change to an intake and carb for the alloy head and do the upgrades to up the horse on the motor . it will be faster . i really adore the fastbacks and have for many years . they are a very comfortable car on a long trip .

 

[alpinefastback]

Bob,

Do you know where I can find an alloy head?
I know I'll also need a different exhaust manifold for the aluminum head. Does anyone make headers for this engine?

Thanks
Jeff

 

[RootesRacer]

Bob,

Do you know where I can find an alloy head?
I know I'll also need a different exhaust manifold for the aluminum head. Does anyone make headers for this engine?

Thanks
Jeff

Be sure to research all you need, its more than the head and exhaust.

Intake, cam, rockers, pushrods, gaskets thermo housing ETC.

If you go the alloy head route, do yourself a favor and get the solex 2bbl intake (SIII/SIV alpine). You will not regret it.

There are several sources of new headers, Sunbeam specialties, and Bill Atalla makes one (which likely will require some mods).

The earlier series (SI-SIII alpine) headers will fit.

The stock SV cast exhaust manifold is a pretty good flowing exhaust all things considered.

 

[RootesRich]

Allow me to ask a dumb question, but isn't the Fastback's engine tilted?
If so, I can't see how the S3, IV and V's intake and exhaust will work without modification.

 

[RootesRacer]

Allow me to ask a dumb question, but isn't the Fastback's engine tilted?
If so, I can't see how the S3, IV and V's intake and exhaust will work without modification.

Thats a good point.

In the case of the exhaust, thats simple plumbing work.

In the case of the intake, you do just the opposite of what folks have been doing for years to put a holbay H120 intake on the vertical alpine engine, and that is to cut wedge shaped slices from the intake, bend and re-weld.

 

[65beam]

fastback

rootesracer is right about having to cut the earlier intakes to mount them so they are level. the problem with trying to use either rick or bill's exhaust is clearance with the frame rails due to the slant of the motor and the position of the starter and steering box .it would be easier to make them from scratch . you also want to retain the fastback's thermostat housing since the top radiator hose is on the right side instead of the left as on the series alpines . the fastback radiators are also a three row which helps with cooling . if you decide to go the alloy head route , you might want to consider one of the early 1725 heads that have double valve springs since the heads on the fastbacks have single springs .

 

[alpinefastback]

If you go the alloy head route, do yourself a favor and get the solex 2bbl intake (SIII/SIV alpine). You will not regret it.

I take it that is one 2bbl carb as opposed to twin single barrels?

 

[alpinefastback]

if you decide to go the alloy head route , you might want to consider one of the early 1725 heads that have double valve springs since the heads on the fastbacks have single springs .

Is there a link and/or book you can recommend where I can learn about the differences in the Sunbeam engines?
Are all 1725cc engine blocks the same except for the mounting points?
So far, it seems I want an early alloy head with the double valve springs. Which series did these come in?
And I want the 2bbl Solex carb and intake from an SIII or SIV?
Are there cam grinds that have better power without driveability suffering?

 

[RootesRacer]

Is there a link and/or book you can recommend where I can learn about the differences in the Sunbeam engines?
Are all 1725cc engine blocks the same except for the mounting points?
So far, it seems I want an early alloy head with the double valve springs. Which series did these come in?
And I want the 2bbl Solex carb and intake from an SIII or SIV?
Are there cam grinds that have better power without driveability suffering?

On 1725s, the blocks are functionally identical, but ONLY the latest series alpine SV 1725 blocks will have the block cast and tapped for the side mounted motor mounts which you will need. Series alpines mount to the front of the motor by a plate that goes between the block and the timing cover.

I would not say you need an early head, in fact I'd recommend the latest heads used on the last SVs and later hunter modeled cars. These are the ones that dont have "tubes" installed for the spark plug recess of the castings. These are best becuase they are SURE to have the larger valves used on the 5 main motors, AND they dont leak oil into the spark plug areas.
You can install the earlier SV dual valve springs, or even use the earlier springs if you so wish. If you are concerned about higher performance and valve float, you can order some stiffer springs from folks like crane to suit your needs.

And answering your previous post, the 2bbl intake is for a single 2bbl carb, not 2 1bbls. The beauty here is that you can mount a contemporary weber carb and end up with a longer lasting tune, great performance and available tuning components.

 

[puff4]

The engine is tilted, yes, and I've always wondered - do the tappet covers leak (any worse) because of it?

 

[RootesRich]

I may have missed this in prior posts, but is there a budget for the engine upgrades? Some of the suggestions being tossed around aren't cheap.

I would strongly suggest you start checking out the UK Ebay site and do a search for Sunbeam Rapier. I know manifolds show up there quite often and are very reasonably priced. That would save you the $$$ in taking a S3/SIV or a SV manifold to a machine shop and having them convert.

 

[rootesrefuge]

Been there, done that. My '67 Arrow wagon is a base model, so had the cast head and single CD150. Easy enough to fix once engine rebuild time came around! You'll need to change at least the head, valve cover, manifolds, downpipe, and camshaft, but it's not a hard swap. If it runs OK now, start collecting the parts you'll need and enjoy the car in the meanwhile.

If your state isn't too aggressive on smog inspections, I'd recommend getting the manifolds from either the UK or Australia. The US versions are just horrible. Even better if you can get them with the carbs on! Just remember the engine is the same as a Hillman Hunter, so used bits are pretty plentiful. A Series V Alpine cam and a '69 Alpine GT head were what I used, but a lot depends on what you can get your hands on. I only had US-spec GT carbs on hand, so I adapted them to fit a pair of Australian manifolds. The Aussie or UK carbs would be a MUCH better choice if you want to stay with carbs. I went EFI and turned mine into throttle bodies when I couldn't get enough adjustment out of the US smog carbs to get it to run right. I've been really happy with the car with the new engine! Now I need to install the overdrive trans that's waiting in my garage.

Of course, if you really want to go crazy, there are a few fastbacks running around with Rover V8s. It fits quite well, and the alloy V8 weighs about what the stock 1725 does. But costs go WAY up with a swap like that.

Jon Arzt
Omaha, NE USA

 

[alpinefastback]

I may have missed this in prior posts, but is there a budget for the engine upgrades? Some of the suggestions being tossed around aren't cheap.

I would strongly suggest you start checking out the UK Ebay site and do a search for Sunbeam Rapier. I know manifolds show up there quite often and are very reasonably priced. That would save you the $$$ in taking a S3/SIV or a SV manifold to a machine shop and having them convert.

I didn't specify a budget, and while I don't want to waste money, cars are the only expensive hobby I have, so I don't mind putting money into a car I know I won't get back.
Thanks for the advice about eBay UK, I've already got automatic searches that alert me when anything new matches, Sunbeam Rapier, Hillman Hunter and Humber Sceptre.

 

[alpinefastback]

And answering your previous post, the 2bbl intake is for a single 2bbl carb, not 2 1bbls. The beauty here is that you can mount a contemporary weber carb and end up with a longer lasting tune, great performance and available tuning components.

I understand the issues with the exhaust manifolds and the engine being canted.
Are there any issues using the 2bbl intake with the engine canted?

 

[alpinefastback]

If it runs OK now, start collecting the parts you'll need and enjoy the car in the meanwhile.

It runs great now, so these upgrades wouldn't happen until next winter. My plans right now are to fix the little things and enjoy the car until I have what I need to redo it.

Of course, if you really want to go crazy, there are a few fastbacks running around with Rover V8s.
It fits quite well, and the alloy V8 weighs about what the stock 1725 does. But costs go WAY up with a swap like that.

I did some research on engine weights and came up with a few engines that are close to the Sunbeam engine and the Rover V8 was one of them.
It's the swap that appeals to me the most, but I know the complexity and cost to do it right might be more than I want to take on.
If there was a step by step how-to with a parts list and a review of how it handled compared to stock I would definitely being going that route.