Upgrading my 1502?

[APka]

5 hours ago, TobyB said:

I don't know about the 1502, but the 1600 engine has smaller ports than the 2002- 

optimally, the manifold matches the ports in the head.  The early 1600 DID get sidedrafts-

I had a set of 1600 manifolds a long time ago, but sold them on rather than modify them to work

on a 2 liter, figuring they were pretty rare.

 

As to parts, first, get yourself Pat Braden's Weber Carburetor book, and Haynes as well.

That will answer your Weber questions, and questions you didn't know you had...

Then you would probably want a pair of 40DCOE or DCOM carbs, a manifold,

a linkage setup (which is not particularly easy) and some form of air cleaner.

 

It's that... easy...

 

But drive it a bit, first.  You may find you want to do suspension work first, 

or something else.  Or sell it and get a Lotus! 

 

My 02,

 

t

 

Thanks for the advice, I will look into reading those before modifying,

 

In terms of driving, I would already like to do work on the suspension, lower it a bit, hopefully improve handling and get a bit more aggressive look... Same question, can I do what people have done to their 2002's on my 1502? And if I were to simply put shorter springs, what do people generally put on in terms of height?

 

Never selling this car ! Family heritage

[Mark92131]

18 minutes ago, APka said:

Same question, can I do what people have done to their 2002's on my 1502?

 

Any 2002 suspension modification can be done on your 1502, you should read the "Stance Thread" to evaluate your options.

 

 

Mark92131

[APka]

I have found this part for sale in france : 

https://www.leboncoin.fr/equipement_auto/1079198751.htm?ca=6_s

40 DCOE 151

Diffuseur 30
Centreur 4.5
Pointeau complet 175
Gicleur principal 115
Jet de pompe 40
Gicleur air freinage 200
Emulseur F11
Gicleur ralenti 45F9

 

It's french, but i'm guessing the numbers are readable

 

These are basically more than 200€ cheaper than anywhere else that I have found for brand new carbs, except these come as built, not fine tuned... Is it worth paying extra to have them "pre tuned" for the car, or is that manageable once i've read the guide to Weber carbs?

Edited March 22, 2017 by APka

[NickVyse]

2 hours ago, APka said:

 

Regarding the VIN number, are you refering to the chassis number? "Fahrgest.Nr" ? 

 

I will also look into the e21 manifold option, but the dual card option kind of gets me excited haha

 

chassis/vin, same thing. email it here for build date and info: BMW <info.grouparchiv@bmwgroup.com>

[Henning]

Don't start with the engine. Start with the brakes and suspension.

The 1502 rear brake setup is the same like on 2002s, but the front brakes have just 2-piston calipers that are too weak for more than 100hp. If you come to switch to a 2-litre engine with side drafts and keep the original engine in the basement, this kind of 1502 brakes will soon overheat when braking heavily.

You will need a 1602, 1802 or 2002 master cylinder (all the same), 1602, 1802 or 2002 brake calipers  (all the same), a reservoir and two more brake lines. And add sway bars, the handling will improve a lot.

 

hen

 

[NickVyse]

personally I'd buy from a trusted source, with some come back. lots of threads about the newest carbs being made with very poor quality control, so a complete lottery as to whether they're going to work well or not. Here's the details of Steve - a UK dealer in used webers, who is also an 02/nk enthusiast. Usually around £500 jetted to your needs. But a twin carb manifold with small ports for your 1600 head will be nigh on impossible to find (not saying a 2 litre version wouldn't work, just not as well unless you also up compression and get a different cam).

 

http://www.02forum.co.uk/memberlist.php?mode=viewprofile&u=4887

[APka]

1 minute ago, NickVyse said:

personally I'd buy from a trusted source, with some come back. lots of threads about the newest carbs being made with very poor quality control, so a complete lottery as to whether they're going to work well or not. Here's the details of Steve - a UK dealer in used webers, who is also an 02/nk enthusiast. Usually around £500 jetted to your needs. But a twin carb manifold with small ports for your 1600 head will be nigh on impossible to find (not saying a 2 litre version wouldn't work, just not as well unless you also up compression and get a different cam).

 

http://www.02forum.co.uk/memberlist.php?mode=viewprofile&u=4887

I was recommended the dual 40 dcoe by https://classiccarbs.co.uk/ , but i'm hoping that they understand that I drive a 1502 and not a 2002.. 

[Simeon]

1 hour ago, APka said:

I have found this part for sale in france : 

https://www.leboncoin.fr/equipement_auto/1079198751.htm?ca=6_s

40 DCOE 151

Diffuseur 30
Centreur 4.5
Pointeau complet 175
Gicleur principal 115
Jet de pompe 40
Gicleur air freinage 200
Emulseur F11
Gicleur ralenti 45F9

 

It's french, but i'm guessing the numbers are readable

 

These are basically more than 200€ cheaper than anywhere else that I have found for brand new carbs, except these come as built, not fine tuned... Is it worth paying extra to have them "pre tuned" for the car, or is that manageable once i've read the guide to Weber carbs?

 

Be careful, they could be Chinese copies. People have had very mixed results with them. 

[APka]

12 minutes ago, Simeon said:

 

Be careful, they could be Chinese copies. People have had very mixed results with them. 

 

That is true, which is why I will ask for proof of them being Weber products (receipt.. stamps etc...),

 

But apart from that, are those specs good for a 1502?

[williamggruff]

Here's your 1600 intake manifold for dual carbs. I'd jump on this immediately if you want it. This is a very rare part at a very reasonable price. 

 

https://www.ebay.com/itm/27258453748

Edited March 22, 2017 by williamggruff

[Simeon]

OK, now is a good time to get some knowledge about the carbs. There are many, many different individual adjustments that can be made. Those carbs may be within a ballpark but they will certainly need your input in tuning and jets will need to be substituted. You can only do that if you understand what they all do.

 

Try this: http://www.lainefamily.com/images/WeberTuningManual.pdf

 

Off the the top of my head, I would say that the chokes are maybe a little small (Diffuseur 30) you might want 32mm as a start. This shouldn't necessarily put you off but the saving starts to shrink if you have to replace lots of parts. If they are copies then this may also be when you have the most trouble trying to find parts that fit. 

Edited March 22, 2017 by Simeon
Added link

[Oldtimerfahrer]

I would seriously think twice about doing performance mods on a 1502 engine, you can enquire in Germany where they are a dime a dozen. It has a lower compression ratio to run on low octane fuel....so if you bolt dual carbs on it, you will get little back other than a significantly higher fuel bill. Taking a stock 2 litre with stock compression gives you some 10hp extra, on a 1502 engine it might be half that...so you spend a lot to get "back" to the 85 a stock eurospec 1602 might have. A really original 1502 is a reasonable investment, putting it "back" to spec would not be financially justified. So financially, if original keep it that way. If not, then you have little financial incentives to return/keep a 1502 to showroom condition. As others have hinted, the 2-litre or even the 1802 are better starting places. That's just the financial view, your creativity shouldn't be stifled by the financial side, but it affects cost of getting what you want. I would think that there are more unregistered 1502's kicking around the UK, so unless it's really truly original and good.... Enjoy in any case, perhaps consider whether you would want a second and whether it would ideally be original or custom. 

Regards,

Andrew

Edited March 23, 2017 by Oldtimerfahrer

[TobyB]

Quote

The 1502 rear brake setup is the same like on 2002s, but the front brakes have just 2-piston calipers that are too weak for more than 100hp

Hen, was that true of the late 1502?  The early 1500/1602 and 1968 2002, yes, but did it persist through to the end?

RealOEM shows a 4- pot, but sometimes the pictures do not exactly match the parts...

 

Things I do not know.

 

t

 

[Oldtimerfahrer]

Quite true, the 1502 had a single line brake system, so many of the components are not interchangeable and it has additional components (balancer or pressure failure switch) to partly compensate for the single line brakes. It has 8:1 compression to run on low octane fuel (I guess that was 87 octane at the time) which was achieved with flat top pistons and jetting the carb differently. It is essentially a 1602 engine so replacing the pistons would be a good start. It was a budget version so a lot of chrome is deleted, some of the trim is painted black, the front quarter glass is fixed, has 4-inch rims as stock and cheaper seats. Dual webers of any sort, with any venturis (chokes) will be "overkill" for a 1502 engine. Downdraft will breath more than amply enough. I have never considered dual carbs as a visual tuning accessory, but they would be on a stock 1502 engine.

 

Regards,

Andrew

[Simeon]

30 minutes ago, Oldtimerfahrer said:

Quite true, the 1502 had a single line brake system, so many of the components are not interchangeable and it has additional components (balancer or pressure failure switch) to partly compensate for the single line brakes. It has 8:1 compression to run on low octane fuel (I guess that was 87 octane at the time) which was achieved with flat top pistons and jetting the carb differently. It is essentially a 1602 engine so replacing the pistons would be a good start. It was a budget version so a lot of chrome is deleted, some of the trim is painted black, the front quarter glass is fixed, has 4-inch rims as stock and cheaper seats. Dual webers of any sort, with any venturis (chokes) will be "overkill" for a 1502 engine. Downdraft will breath more than amply enough. I have never considered dual carbs as a visual tuning accessory, but they would be on a stock 1502 engine.

 

Regards,

Andrew

 

While you are no doubt correct, don't forget that sidedrafts can be tuned on smaller engines than 1600. Think of small Datsuns, FIATs and Alfas. 

 

Whether it it is worth it or not is a different question to whether or not DCOEs are flexible enough to be tuned for any engine.