Dennis

Joe

But apart from dual carbs and the emissions equipment - not to mention the bumpers - is there anything else different between the US and european spec 1500s?

Dennis

Joe

Bruce Nelson 79 Spitfire the "rejuvn8r"

I think you may already have a head start...Did the 76 not have Flat Top pistons?

But it was my understanding that ALL of the american 1500 engines had the 7.5:1 compression ratio (dished pistons) because they had to burn lower octane unleaded fuel.

BTW, I'm not looking to be some sort of "european-spec" purist, it's just that the engine was properly set up for the european market, unlike the de-tuned abomination the US government forced on us.

So as far as "re-tuning" a "de-tuned" american-spec engine to more or less the european set-up, it's going to be:

1. Switch back to dual carbs
2. Switch to flat-top pistons for better compression
3. Switch cam - maybe a "Triumph Tune" Fast Road?
4. Strip out emissions system (air pump, carbon canister, etc) and catalytic converter

Shouldn't be a big deal as I'll probably rebuild the engine anyway. Anything else?

Other "non-european spec" performance bumps could include -

1. 4-2-1 exhaust
2. electric fan on radiator
3. flowing the head & manifolds
4. richer carb needles
5. K&N air filters
6. electronic ignition
7. oil cooler

I don't think I'll need to go as far as fully balancing the internals, lightening the flywheel, or upgrading the valves, con rods, springs, guides, etc. I just want an engine that will be quick in traffic and not strain to keep up, not a racer...

Dennis

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Your Specs sound just like my car, However I did have the engine balanced and I would NOT recommend an oil cooler (unless you know you have a heat problem. Very unlikely!)

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Dennis

I still have an aluminum flywheel from when I was using the highly tuned engine for autocross. Unless I keep the revs up above 3000 or have my foor in the throttle, it wants to buck.

The heavier the flywheel is, the the more mass is there to resist the bucking motion.

Next time I have the gearbox out, I plan on installing a stock flywheel.

Joe

Everything I've read heavily leans towards an oil cooler almost being a necessity. Particularly in higher-performance engines - I guesstimate the changes I plan to put the power at the flywheel around 95-100 BHP. They also suggests using a thermostat control on it to avoid over-cooling the oil - viscosity problems, etc.

Oh, I live in Central Florida where we have like 200 days a year of high temperatures in the 90s. So I am at least a little concerned about a possible "heat problem."

Joe,

I don't intend to lighten the flywheel at all. That just allows you to rev up more quickly - great if you're racing, not really needed otherwise. Like I said, I want the car to be quick in traffic - not uncontrollable!!

Dennis

I do have a an electric fan mounted in front of the radiator with a manual switch so that I can turn it on in rare cases where I am stopped at a light for an extended period. I have an oil temp gauge and have never had the temperature get out of hand.

Joe

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For what it's worth, I live in Southern AZ and I removed the oil cooler from my red car after determining that I did not need it.

I do have a an electric fan mounted in front of the radiator with a manual switch so that I can turn it on in rare cases where I am stopped at a light for an extended period. I have an oil temp gauge and have never had the temperature get out of hand.

Joe

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Dennis

Run lightened flywheels on my Spitfires without any downside. They do more than just let the engine rev more quickly, they allow more power to be applied to the wheels, and not spinning up the flywheel.

Cheap welders respond well to a cheap fan on them. Cools them and greatly reduces the thermal tripping. Works on more expensive welders too. Really good ones already have cooling fans.

One other alternative, (that could be the best of both worlds)is to fit a Oil to Coolant heat exchanger, as is used on many modern cars and trucks. 'When I get around to it' I have a nice unit from a VW golf that appears to fit nicely at the base of my oil filter, I will just have to Plumb it to the coolant lines.
The advantage to this is, at start up it will help bring the cool engine oil up to temperature more quickly, and if the oil temps should start to get too high (hotter than the coolant) it will help cool the oil (Cool is always a relative term here)

There is some great info in catalogues like Triumph Tune, but remember they are selling stuff. I knew the Hurrels when Sid had a small 'speed shop' in the local High Street and was selling his SAH Triumph accessories. Terry (his son) took over and expanded (with help from Moss) into Triumph Tune.
I had a lot of respect for Sid.........

The TT Fast Road Cam exists in many guises, check out what Ted Schumacher and BPNW have to offer, I think you may see the same profile if you compare specs.
I really wanted to discuss Cams with the Guys here a few months back, But Gareth got in on the thread, and it went to pot!
Too bad! Basically I'm pleased with my Fast road that came from BPNW, but I'm not sure that it's the BEST Cam for road use.

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Dennis, if oil temps really concern you, first install a gauge or get an oil temperature reading (This was the advice I got from both Chevron and Pennzoil's tech departments) Optimum oil temps are between abot 170F and 220F, and a little higher (240F) would still be OK. This is considered optimum! below 170F is considered too cool and engine wear will increase.

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I don't know that I'd say that I am "really concerned" about oil temps. I'm going largely off of Calum Douglas's "Building a Reliable Spitfire Engine for High Performance v1.4" that suggests installing an oil cooler.

Personally, I never had the problem with either my '70 Mk3 or my '80 1500 - both totally stock. But I was running those in Chicago and North Carolina respectively. The heat down here in Florida is far more oppressive. I'm figuring on the Spit being a daily driver - in sunny weather anyway (I'm retaining my Jeep Grand Cherokee for the less than sunny days). My normal daily driving is very much local stop & go stuff, no expressway driving - so I'd expect the oil temp to rise pretty quickly.

Dennis

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As I have said, my engine is virtually the same spec as what you are aiming for (it was dynamically balanced with Flywheel and Clutch by the way) and will take 15-20 minutes to reach 170F.
The maximum I have recorded was just over 200F after 35 minutes or more at a steady 80-85 mph on a hot summers day (Yes, we can get 100F days here!)

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Hmm, not to nitpick - but is most of your driving at steady, higher speeds? As I said, I'm anticipating a lot of stop-and-go, lower speed driving in the Florida heat. But then again, Joe is backing up your opinion and he's driving in the Arizona heat...

I might just wire in an oil temp gauge to start and see how it goes.

BTW, does dynamic balancing make a big difference?

Dennis

Hmmm, I have had unbalanced (stock) engines that have been very smooth, and I have had (one in particular) that was not. Unfortunately, the engine in my currant Spit was Bone stock before I rebuilt it from balanced components and added all the Bells and whistles.
Yes the difference in the engine is Night and Day, but what part in the transformation can I honestly say was down to the Dynamic balancing??

What I can say; I rebuilt a 1500 engine for a friend a couple of years back, and asked a trusted machine shop to balance the Crank, Flywheel, Clutch and Con rods. I was astounded as to how much metal had to be removed in places!
On another computer I have some pics, I'll try and post them.

My philosophy is: 'Spend the money on the hard to reach parts' ie. Build up the best block you can, if money runs short you can add the Carbs, manifold, ignition system later, but it's not so easy to dive in and Balance the bottom end!

For what it's worth, I did at a later stage (when changing my clutch form a Horrific Quintin Hazel) Have the Flywheel lightened by 2 or 3 Lbs, I think the engine was, perhaps, a little livelier, but even though the machining only cost me a case of Beer, It was not my 'Best Bang for my Buck' That would have to go to the Twin HS4's or the Electronic Ignition.

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"BTW, does dynamic balancing make a big difference?"

Hmmm, I have had unbalanced (stock) engines that have been very smooth, and I have had (one in particular) that was not. Unfortunately, the engine in my currant Spit was Bone stock before I rebuilt it from balanced components and added all the Bells and whistles.
Yes the difference in the engine is Night and Day, but what part in the transformation can I honestly say was down to the Dynamic balancing??

What I can say; I rebuilt a 1500 engine for a friend a couple of years back, and asked a trusted machine shop to balance the Crank, Flywheel, Clutch and Con rods. I was astounded as to how much metal had to be removed in places!
On another computer I have some pics, I'll try and post them.

My philosophy is: 'Spend the money on the hard to reach parts' ie. Build up the best block you can, if money runs short you can add the Carbs, manifold, ignition system later, but it's not so easy to dive in and Balance the bottom end!

For what it's worth, I did at a later stage (when changing my clutch form a Horrific Quintin Hazel) Have the Flywheel lightened by 2 or 3 Lbs, I think the engine was, perhaps, a little livelier, but even though the machining only cost me a case of Beer, It was not my 'Best Bang for my Buck' That would have to go to the Twin HS4's or the Electronic Ignition.

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Budget = shoestring

I plan on rebuilding any engine I get, regardless. The basics - magnafluxing, checking the top for flat, new seals, bearings, thrust washers, con rods - are a given, I think. From there, what do I do during the rebuild and what can I delay on? What's the "best bang for the buck?" Looking to up the horsepower from the de-tuned, US spec level.

1. Flat-top pistons? Another given, by your concept of "spend money on the hard to reach parts"
2. Dynamic balancing? Not sure if this is a given. To me it would seem to depend on how much of an improvement it is over just statically weight-matching parts (pistons, etc) that's a pretty standard part of re-building an engine anyway. I understand that dynamic balancing WILL make a difference. The question is whether it's a difference that's worth the money in a daily-driver road car.
3. Uprate the cam? Does seem to be a "given." Who wants to tear apart a head again after rebuilding the engine? The specific cam would appear to depend on the intended driving.
4. Lighten the flywheel? I've heard yes and no on this one. The main benefit seems to be quicker spin-up of the engine. Advocates are claiming it also gives more HP to the rear wheel. I'm not a racer or a red-line fiend, so I'm not too sure about this. I can get the flywheel lightened for only $50, but is that really the best place to spend $50 on a shoestring budget?
5. Flowing the heads and manifolds? Definitely. This is something I can take my Dremel to and do myself. No real cost except my time. Lotsa "bang for the buck!"
6. Twin HS4s? Maybe not at first. Carbs = $$$. Plus a new intake manifold. Might have to limp along on the single ZS for a while.
7. Electronic Ignition? Not a real necessity to get on the road, but I think I'll spend the cash anyway. On my other 2 Spits (which were far newer at the time), I was FOREVER fiddling with the distributor. Rotors & points were always needing replacement/adjustment. It's worth it to me just to avoid the headaches.

Dennis

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There is some great info in catalogues like Triumph Tune, but remember they are selling stuff. I knew the Hurrels when Sid had a small 'speed shop' in the local High Street and was selling his SAH Triumph accessories. Terry (his son) took over and expanded (with help from Moss) into Triumph Tune.
I had a lot of respect for Sid.........

The TT Fast Road Cam exists in many guises, check out what Ted Schumacher and BPNW have to offer, I think you may see the same profile if you compare specs.
I really wanted to discuss Cams with the Guys here a few months back, But Gareth got in on the thread, and it went to pot!
Too bad! Basically I'm pleased with my Fast road that came from BPNW, but I'm not sure that it's the BEST Cam for road use.

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There ARE several "Fast Road" cams from Triumph Tune to choose from aren't there? There are some from other manufacturers as well, right? I guess it could get quite involved as to just which cam is best for a particular engine as well as being dependent on how it's set up and the type of driving intended. When I get to that point (still choosing between 2 different 1500s to buy right now), that would be a good point to address. I'll be expecting your input!

Dennis

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Run lightened flywheels on my Spitfires without any downside. They do more than just let the engine rev more quickly, they allow more power to be applied to the wheels, and not spinning up the flywheel.

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Just had a thought about flywheels.

Neither of my candidate cars have an O/D. Does a lightened flywheel help a Spit at all to run at interstate speeds for long periods?

If so, what's the appropriate weight for a flywheel in a daily driver?

Dennis

During acceleration it makes a small difference - as well as increasing the forward speed of the heavy car, the engine also has to increase the rotational speed of the heavy flywheel (not only that, it has to do it again and again as you change gear and the engine revs drop). If the flywheel is lighter, more of the engine's power can go to accelerating the car.

Running at interstate speeds for an extended period without OD is a pain...

Richard

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Lightened flywheels will make no difference whatsoever to running at interstate speed (or any other constant speed) - once you've got the engine spinning at a certain speed, the flywheel makes no difference, other than smoothing out the bang-bang-bang output of the engine as each cylinder fires.

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Dennis

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Wouldn't a heavier flywheel actually be MORE desireable in "smoothing out the bang-bang-bang output?"

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Absolutely, yes. It is a compromise. Manufacturers building road-cars make the flywheels adequately heavy so the engine runs smoothly, particularly at tick-over. Racers lighten their flywheels because they don't care about smoothness, and their engines are rarely at tickover and if the car shakes a little when they are then so what? At higher engine speeds it doesn't make much difference.

If you want a reasonably easy-to-drive road car, you probably don't want to stray too far from what Triumph reckoned was an appropriate weight for the flywheel. Given your cost constraints, and what Joe's already said, my instinct would be not to bother lightening the flywheel. If I were to do anything to it, it would be just to make sure it is balanced. But that's just my opinion!

Richard

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During acceleration it makes a small difference - as well as increasing the forward speed of the heavy car, the engine also has to increase the rotational speed of the heavy flywheel (not only that, it has to do it again and again as you change gear and the engine revs drop). If the flywheel is lighter, more of the engine's power can go to accelerating the car.

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Doesn't the lightening cause the flywheel to "smooth out the bang-bang-bang output" LESS? Making it less "comfortable" to drive in that respect?

Dennis

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Running at interstate speeds for an extended period without OD is a pain...

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Dennis

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Every time I'd read this I'd think, "What the heck are they talking about? I used to drive my '80 Spit cross-country all the time!" But then I remember that was back in the early '80s - when we had that ridiculous "national" 55 MPH speed limit...

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Yes - I'm writing from a British perspective, where 70mph is the official speed limit, and 80mph is closer to how I used to drive (before the twin attacks of speed cameras and extortionate fuel prices took their effects on me). That little Spit engine is revving pretty high at 80mph if you don't have O/D!

Richard

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Every time I'd read this I'd think, "What the heck are they talking about? I used to drive my '80 Spit cross-country all the time!" But then I remember that was back in the early '80s - when we had that ridiculous "national" 55 MPH speed limit...

Yes - I'm writing from a British perspective, where 70mph is the official speed limit, and 80mph is closer to how I used to drive (before the twin attacks of speed cameras and extortionate fuel prices took their effects on me). That little Spit engine is revving pretty high at 80mph if you don't have O/D!

Richard

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The interstate speed limit is now a much more realistic 70 MPH in most places. But as I said, I foresee almost all of my driving to be in-town, not expressway. So an O/D (although it seems to be one of the most sought-after accessories) is not real high on my priority list...

Dennis

1. OD is something I would not be without if the car were used on highways. My black car has a 6 speed Honda gearbox, the top two gears are over 1:1 ratio. My red car has a MkIV full synchro 3-rail gearbox with a D-Type overdrive. Both can adequately keep up with traffic without taxing the engine.

2. I agree with what has been said about light flywheels. Racers love them because they put more engine power towards going fast. The downside is when you are driving around town at low rpm, the car tends to buck because there is less inertia of the flywheel sustaining a constant speed. As I stated previously, now that the engine in my red car is not being used for competition, I plan on changing out the aluminum flywhell for a stock one next time I have to tear into the gearbox.

3. Balancing everything that is rotating as a single unit is highly advantageous. However, if you change anything out (such as the clutch or flywheel) it is no longer balanced and will need to be re-balanced to return it back to it's former state. Balancing each component individually will probably be as good as necessary for street use if you are not prone to revving high into the engine's capability. When I replace the flywheel, I will make sure the one I put in is balanced and not worry about dynamic balance until next time I do a complete engine rebuild (which hopefully won't be for many years).

Joe

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1. OD is something I would not be without if the car were used on highways. My black car has a 6 speed Honda gearbox, the top two gears are over 1:1 ratio. My red car has a MkIV full synchro 3-rail gearbox with a D-Type overdrive. Both can adequately keep up with traffic without taxing the engine.

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But if anyone needs one, there's a 3-rail tranny with an O/D on craigslist in Jacksonville, FL right now. Asking price is $575.00

http://jacksonville.craigslist.org/pts/1817697893.html

Dennis

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2. I agree with what has been said about light flywheels. Racers love them because they put more engine power towards going fast. The downside is when you are driving around town at low rpm, the car tends to buck because there is less inertia of the flywheel sustaining a constant speed. As I stated previously, now that the engine in my red car is not being used for competition, I plan on changing out the aluminum flywhell for a stock one next time I have to tear into the gearbox.

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Dennis

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3. Balancing everything that is rotating as a single unit is highly advantageous. However, if you change anything out (such as the clutch or flywheel) it is no longer balanced and will need to be re-balanced to return it back to it's former state. Balancing each component individually will probably be as good as necessary for street use if you are not prone to revving high into the engine's capability. When I replace the flywheel, I will make sure the one I put in is balanced and not worry about dynamic balance until next time I do a complete engine rebuild (which hopefully won't be for many years).

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Dennis

THat is why I will just check the balance of the flywheel and clutch when I change over from the aluminum to the stock steel one.

Joe

I'm looking at all of this as what to integrate into an engine rebuild, what to put off for later (as finances permit), and what just isn't needed at all for my purposes.

Joe offerd the opinion that dynamic balancing really isn't needed for ordinary street use, individual component balancing would be good enough.

Now you seem to be saying that as long as I'm rebuilding the engine anyway, I might as well have it dynamically balanced because it only costs $50-60.

While taken by itself, the $50-60 to dynamically balance the engine isn't much, combine it with the $50-60 that I don't need to spend on lightening the flywheel along with the $160 that I'm not going to spend on an unneeded oil cooler installation and there's the $260-280 I can use for a "Triumph Tune Fast Road 83" camshaft that will give a good performance boost for me.

Remember, my budget = shoestring. I don't want to skimp on necessities, but I can't really spend on "nice to have" or "you might as well do it anyway" sorts of things. I'm looking at real, solid, discernible improvements in performance for my intended type of driving - mainly around town, stop-and-go. I'm not racing or doing extended highway driving.

Dennis

But if you are going to do the bulk of the work yourself and farm out only necessary machine work you can't do yourself, that is where the balancing cost will be highest.

Take a look at The cams TSI offers. THat might save you some money to apply elsewhere.

http://www.tsimportedautomotive.com/camspecs.html

I am running the TSI275-4 cam and like it a lot.

Joe

I had only planned on having a shop clean & flux the block and make sure the deck is flat. Other than that, I feel capable of doing all of the work myself.

BTW, thanks for letting me know about TSI. Looks interesting...

Dennis

http://auskellian.com/paul/links_files/spitfire_cam_specs.htm

(thanks Paul!)

The early 1296 factory cam is a pretty good compromise between power and civility.

ISTR that you will need to fit cam bearings into a 1500 block to run it though.

Carter

Joe

I use the BPNW 270 and I am pleased, but as you can see form the list that Joe gave the link to, there is a lot out there to chose from.

DON'T be tempted to use a 'used' MkIII Cam!

You will not get the most from your Cam until you improve the carbonation.
You May consider spending All the money we are saving you there?
Or you could just buy us all a round of drinks?

Be absolutely sure that you check all the parts to the valve train to be sure that you have the geometry correct.

High performance cams don't always go in without making adjustments to the rocker geometry and push rods.

Cheers,
Joe

Dennis

For that matter, you could order the european spec Mk3 cam which uses bearings and have the same or similar grind with cam bearings.

I am not sure how the two cams compare but I would be surprised to find the 1500 cam to be more agggressive than the Mk3 one.

Joe

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As far as I know, there were only the MkIII grind (which was first used on the Herald) and the North American (Corporate, Emission) grind that John Kipping refers to as 'The Dog Turd' (I guess he doesn't like it?)

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I admit that I'm no expert on cam design, but would that have worked? I thought that BL maxed out the displacement by lengthening the piston travel on the same block while keeping the bore size the same as the 1296cc motor. Wouldn't that need a different cam profile to work?

Dennis

I used a 1296 cam in the only 1500 I have ever had and was quite pleased with it. Getting the twin SUs tuned to the engine was the biggest problem. I ysed HS2's from a Mk3 rather than HS4s from European spec engines. They worked well after I finally got the needle profiles right.

Joe

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You will not get the most from your Cam until you improve the carbonation.
You May consider spending All the money we are saving you there?
Or you could just buy us all a round of drinks?

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Beer money is ALWAYS kept separate from car money. Never the two shall mix.

So I'll always have a couple of bucks to buy a round or two...

Dennis

With a 1500 for the street I wouldn't look at anything that has a power curve that goes above 6000rpm. If you are going to do the engine and lighten, balance, etc...one that goes to 6500rpm would be OK but for a street car I would not go above that 6000 mark very often.

As for cam bearings...on a street car you can do it or not...it seems to be irrelevant. I have never seen the cam journals wear to a point where it's a problem. The bearings are an easy install, they just press into the already existing bore. You may have to as it is tougher and tougher to find cams with the larger OD.

As for carbs...on the 1500 if you keep the cam milder you can stick with a 1.25" SU's and you won't notice a serious drop in performance over the 1.5" SU's. If you work the cam a bit and do some port work on the heat you will most certainly want to use the 1.5" or a single side draught weber.

aaron

The result was that the inside two cylinders got a richer mixture than the outside two. So wither the inside ones ran rich while the outside two were OK or the outside two ran lean while the inside two were OK. Neither of which is very good for longevity of the engine.

I used twin DCOEs on the 1296 I originally had in my black car as it was strictly used for autocross. When I replaced the engine with the Honda unit, I put it in the red car and switched the carbs out for Twin SUs. I found that the DCOEs are not very good for traveling between various altitudes. THe SUs are much more forgiving.

Later I fabricated electronic fuel injection for that engine and am much happier with the overall performance.

Joe

Seeing as budget = shoestring and carbs = $$$, that's probably an upgrade I'll put off until later - as finances allow.

So, does anyone have any ideas of how to boost the performance of the sickly ZS stock carb? I figure that a rebuild never hurts. Also that flowing the intake manifold and mounting a K&N air filter will help it breathe better. Anything after that?

Also, if I opt to upgrade to dual SUs later on, can the 1500 use the manifold off of the 1296cc motor?

Dennis

There are several things you can do to the ZS carb, but they will be expensive

You can get a SU set from around $250

The 1300 and 1500 manifold are the same spacing.

I have a an air horn somewhere around here.

You may want to look on Ebay U.K. they seem to have more Twin carbs and Manifolds there. You could just get the manifold and modify a pair of MGB HS4 SU's
On the Stock inlet manifolds the steel water pipe tends to rust out. This is relatively easy to replace with Stainless of Copper.

Carter

However, I am looking at doing a complete frame-off restoration. As I said, budget = shoestring. So I can't afford to do EVERYTHING at once, as much as I would like to. I would like to return the Spit to the road ASAP though. I see myself doing a lot of things to get the car "roadable" again, while putting off others for when more funds become available.

So the carb swap seems like a probable item to defer until later. I could wind up driving the Spit for a while with the original, stock carb. If there is an inexpensive way to get any more 'oomph' out of sickly little thing, I'd like to do it until I could afford to buy a Weber sidedraught or dual SUs or whatever I eventually opt for...

Dennis

Bruce Nelson 79 Spitfire