Alfa Pages

[Knight]

I have just bought a Kit car, which has a rear mounted 1.5 Alfa-sud engine on twin carbs.....I think its got about 90-100bhp.....my intention is to aquire and tune a 1.7 16V engine, I am new to Alfas and the people who offer the tuning parts, your advice would be much appreciated:-

100bhp/litre is quite achievable on a 16v 4cyl engine so I'm aiming for 170Bhp at around 7000rpm...or possibly more, and I would like to do this on carbs - not injection.

Will a set of 40's from a 1.7 8v be up to the job or 170Bhp?

Are aftermarket manifolds available to mount carbs on the 16v heads, or do you think a set of 8v manifolds could be welded up and modified to fit?

What Cams, pistons and con-rods are available for the 16v off the shelf?....I'm told junking the hydraulic tappets is the done thing!

Who sells performance/race exhaust systems for the 33 1.7 16v?.....I will need the manifold system only, and make my own back section to suit my kit-car.

Is anyone generally reccomended to port the cylinder heads???....or offer an exchange service, contact details would be handy!

any advice will be much appreciated, e-mail me on stephen_knight@eea.co.uk or call me on 0787 9427945 mobile

cheers

stephen

[Matt Stolton]

Much as i am the first to sing the praises of carbs, when it comes to the 16V, I would stick with the throttle bodies and ECU/injection that comes with them.

After market throttle bodies, Weber Alphas for example, are horribly expensive, especially when you consider that alfa fitted very good throttle bodies as standard to the 16V engines. It makes sense to use what are very expensive freebies. Just get the loom and ecu from the donor, and plumb it in. You would also need to change fuel pump, to increase the pressure suitable for injectors, and mess with return lines and stuff, but well worth it. It is also feasible to port the existing plenum, to claw back a little torque, or better still, use one from a 145, which has a more torque biased shape, to further make it driveable. It must detract a little from top end breathing, but its negatives are minimal, compared with its affect on overall package.

Carbs are a compromise, between slow running idle air flow, and high rev breathing. It is all nigh impossible to get both perfectly, as one inhibits the other. However, with throttle bodies, injection and a ECu, perhaps with a piggy back chip and map, you can retain low engine speed performance and emissions, and still get top end performance.

I myself have tinkered with a 16V in my P4 project, mostly hot cams, chip, enlarged valves, and some serious headwork. I still haven't had it mapped yet, but realistically I think it will nudge to 180BHP at the flywheel, perhaps more. However, it is still usable day to day, and torque is still available down low, so it is not a pig.

Carbs can be set for high end RPM power, but to keep them able to serve well low end, and not be a pig to drive around town, is impossible.

If you are around Tuesday next (19th) Me and the car will be at clovertech in east london, having some bits and bobs done, mostly to the P4 bit. Your are more than welcome to come and have a look and a chat with Lloyd, who conceived and built most of the clever stuff. Or try his web site and have a chat with him.

http://www.clovertechuk.com
_________________
Regards

Matt

Ex Alfa 33 'GTA' (P4 with Knobs On)
Now cruising in a 166 3.2 Ti!!

[knight]

Hi Matt, interesting stuff......I must admit I'm still deciding between a 1.7 8v on 40mm carbs.....or a 1.7 16v on standard throttle bodies and an aftermarket injection system (Alpha/Emerald).....my main concern is the difference in weight between the 8v and 16v.....reason being that the engine is hanging out the rear of the car on a beetle gear box and an extra 10-20Kg is not gonna be welcome......

I have also heard that tuning parts for the 16v are well expensive, to raise the compression means 4 adjustable cam timing sprockets.....and cams are £800 a set......

considering all this I'm swaying toward the 8v, because of potentially low weight and the ability to tune it on a sensible budget.....like 40mm carbs and 16v pistons for a 10.8CR....the kit car only cost me 3K so I dont want to spend silly money on an expensive motor that will be worth more than the car!!!!

[paddy granger]

Just a quick question - you mention its using a Beetle gearbox. Does this box have a different diff or does the higher rpm of the Alfa Boxer solve this problem?

Edit : Checked out the numbers with a VW 1302 box, which normally allows a Beetle to go 115 km/h. Running at 6200 rpm , with 195/50 R15's, your car would go 179 km/h. 7000 rpm would convert to 208 km/h!

Handy link:

http://www.juric.org/mopar/tools/topspeed.php

[mark pollard]

Been there - done that with a Minari kit car. A tuned 8v will cost quite a lot just to bring it up to standard output for a 16v. I would estimate about £2k required to raise output to 130bhp at the wheels for an 8v.
I have just bought a 16v for the Minari and am planning to use an Omex ecu(+a few sensors) on standard fuel kit with a few mods to the induction/exhaust tracts. I hope that will release about 145 bhp at the wheels and cost about £800.

[knight]

I'm now too considering the 16v .....again!.....I have since found that I can get an Emerald ECU system fitted up to a 16v, and be in the 145-150BHp at the flywheel......I had considered the 8v but am now swaying away from it, as it will be the lighter engine, but is gonna be hassle tuning it up......throwing in a set of 16v pistons into an 8v sounds easy, but I bet it would open up all sorts of problems I dont want to encounter......for starters I just want to get an engine mount it in the car and go have some fun......and I think the 16v with an aftermarket ECU system will be the best bet....then at some later stage I may consider some head work to get it breathing better.

cheers

stephen

[lesthegringo]

I put an Emerald M3D unit on my 16v - if you are interested take a look at www.alfasprint16v.fws1.com

Les

[GaryUK]

I disagree with Mark. With just a air ram, performace filter, minimal inlet manifold work/tidying, carb rejetting and a rolling road tune my old 8ver would beat my pals 40K 16ver to 60mph CONVINCINGLY. His 16ver was running 100%, well maintained, decattedand setup for no cat so somewhere between 132-137BHP.

And it wasn't just my driving, the 8v was faster with loads more low down torque making it alot more drivable. I know the 8v engine was rebuilt at abut 50k (110k at time of comparison) but just blueprinted no differenet cams etc. It was very well balanced as an engine as it would get near to 8k before sounding feeling nasty (solid rotor arm). It still was producing good power at 7k where with most 8vers the power has completely gone off at about 6.5k.

The 8v unit is alot tougher as well when I scrapped the car it was run round the yard stuck in 2nd at full revs 8k+ and the engine didn't die after1/2 an hour, the clutch exploded.

[lesthegringo]

Here's my ten pence worth

For a front wheel drive car, the 8V is probably the better engine, as it gives a better balance by not being all or nothing. Torque steer with lots of power at high revs is difficult to contain, and makes the car more unpleasant to drive, unless you have the power steering. It has the advantage of being simpler, cheaper to tune (at least for lower stages if you don't want masses of power), lighter, and you can change the No 3 spark plug without taking a course in gynecology. The carbed version is simple to maintain and troubleshoot, and can be converted to throttle bodies (relatively) cheaply and simply. The power delivery is smoother, in my opinion, with the injection version being very elastic, and can handle the power steering forces better than the 16v at low revs.

For a lightweight car, or a rear wheel drive special, the 16v chracteristics will be more suited. Wheelspin just wastes power without torque steer throwing the car all over the road, and can help in keeping the engine on the boil when pulling away quickly from a start. Access is very much improved unless you really make a cock up if the installation, so maintenance is easier generally, plus the probability is that you will be junking some or all of the standard injection hardware, making the whole lot a lot more simple, especially with the Emerald system and the solid state ignition system (no dizzy). The engine does give more power, at higher revs, and can be tuned to give a bit more torque without spending any more than a refurbishment would cost (though it is still higher than the 8v costs).

comments?

Les

[knight]

As my current alfa-sud 1.5 carbed engine is hanging out the rear of the car on a beetle gearbox, in a tube frame sandrail chasis (road registerred), I too agree with les.....the power charicteristics will suit a rear/mid engine car.......hence after digesting much info from this forum I shall be insertuing a 16v lump in the new year on standard throttle bodies and Emerald electronics......minimum fuss......maximum fun

[baiones]

Hi!

Nice car you got!!

Can you post pictures of the engine fitting ?



I recently bought an 1.7 16v engine to through into my QV, but was planning to keep the Dellortos...


But after reading this i dont know...
_________________
Carpe diem!!

Baiones


ALFA ROMEO 33 1.5 QV
ALFA ROMEO 33 1.7 QV
ALFA ROMEO 33 s16 QV
ALFA ROMEO Sprint 1.3
ALFA ROMEO 156 SW "Train Edition" ( it's a JTD... )

[knight]

As far as I'm aware twin carb manifolds are not available for the 16v.......fitting the twin carbs to a 16V will require you to heavily modify the standard inlet manifold via a lot of Aluminium TIG welding, Les has done this for his Jenjey 45mm throttle bodies......personally I think its a time consuming and costly exercise, but I'm not trying to put you off doing it......I'm just saying that the 16v standard inlet system is very good and is well worth keeping.......fitting an aftermarket ECU and re-mapping the engine is the best route to go in my opinion

cheers

Stephen

[lesthegringo]

yes, having done the conversion, unless you are going for a race spec where cost is no issue, then keep the standard throttle bodies as they are good quality items - it's what I'm doing for my next project

Les

[Alan]

Hi guys,

Time for my input on this. I run a 33 rally car in the UK. It's a 1600cc - 1500 crank with 1700 pistons. This is due to class limit of 1600cc.

My current engine spec:
Forged 87mm pistons (made by Arias)
Std 1500cc crank
11:1 comp ratio
Std 16v cams and hydraulic tappets
Ported heads with bigger valves on inlet and exhaust
Home made inlet adaptors (cut from big blocks of alloy!)
Jenvey 45mm throttle bodies
Home made exhaust system

This produced 160bhp at 8000rpm - just loves to rev.

I've now got a set of higher lift, wider duration cams made up by Kent which should lift the power to about 180
but the block has a cracked bore so needs replacing

And now a question: the pistons have a lower 'deck height' than the std 8v pistons ... so had to take a lot of material off the top of the block to get the right CR. Which meant using shorter cam belts (from a Renault Safrane!) and machining smaller idler pulleys to match. This is causing rapid cam belt wear (so would only recommend this for low mileage use!). Has anyone else ever tried this / got any experience / suggestions?

I'm not sure if the cam belts are running too tight, or if they're not as good as the Alfa ones and are wearing too quickly. I'm using Gates belts which I'm told are good quality.

Look forward to hearing your thoughts folks .....

Bye for now

Alan

[lesthegringo]

I made the cam belt tensioners from billet aluminium, turned to give a larger diameter than standard. this allows them to take up extra slack due to reducing deck heights, plus of course they spin more slowly. I got them black anodised to give them a harder surface and shelled out £30 for four SNFA bearings with shields.

You could try that...

Les

[knight]

Alan - heres some food for thought for you.....I was previously a design Engineer at Mountune Race Engines where I did a lot of work on the Ford Puma and Fiesta super 1600 engines, otherwise now known as JWRC......215-220-bhp at 9000rpm .......your throttle bodies are too big buddy.....you should be using 42mm maximum, and you should aim for an inlet tract length of around 11-12.5 inches from the back of the valve to the top of the trumpet.......as you are also running throttle bodies, run the inlet axis at around 20 degrees from the vertical.....as bends in the inlet tract will kill the power.....I suspect you are running them vertical???

as for the exhaust, the primary diameter is very important....too big, even by an 1/8th of an inch and you will lose a lot of power......1-3/4" is best for a 2.0 BTCCC car (280Bhp)....I would suggest you use 1-5/8" outer diameter, all in 18 gauge for the 1600......the standard Alfa 16v exhaust primary diameter is way too big in my opinion.......48mm = about 1-7/8"....bad news

just remember this.....big area = slow air flow.......small area (but not too small) = fast air flow in both the exhaust and inlet.....Personally I would do the modifications listed above before you change the cams

[knight]

I forgot to mention I have done some work on cam belts in the past.....I seem to remember there being many different types of tooth shapes that are used by the belt manufacturers, ther differences can NOT be told with the naked eye.......do not be afraid to do a web search for Gates, or the original belt manufacturer.....you will soon find that Gates have a UK technical centre, contact them and they will point you in the right direction with regard to correct belt and tooth selection.

cheers

stephen

[hugh jinjin]

Stephen- nice to have a professional opinion on the forum, I hope you will keep us all informed on the progress of your project and I will be looking for some more 16v tuning ideas! Inclining the throttle bodies is so obvious if you actually think about it, though needless to say I hadn't. Good tip. In your 1st question you asked about off the shelf exhaust manifolds. Iresa still make one, you should be able to find their site with a google search. I do however think that your information on exhaust primaries is wrong. The 16v has primary pipes of about 38mm not 48mm.


Alan-interested to hear about your cams. Are they re-grinds and if so how much more lift and duration have they got? also do they still have phased lobes or not, are you going to be using solid lifters and what spec of valve springs do you intend to use?

[Alan]

Guys,

Thanks for your comments.

Ref the cam spec - they're not regrinds, they're from billet. Not enough material on the originals to regrind, unfortunately. So I had to cough up and got the billet ones from Kent Cams. They give 1mm more lift and 290 deg duration which is quite an increase on standard. Okay that means the power will be up the top end ... but with a 5.3 diff I need quite a revvy engine, and I've got mappable injection and ignition so should be able to map it to be reasonably driveable and not too peaky.

Ref the throttle size and fitting ... before the heads were modified, we did some work to test the original throttles, and they were very restrictive once we'd got the bigger valves in the heads. Agreed that steady state flow, not with the piston going up and down, so I know you can go too big. And yes, I've done the obvious and fitted the throttle vertically so there is a gradual bend in the inlet port - but it's not straight / bend / straight, it's a continuous gradual curve all the way from the throttle base plate to the port. To change it now I'd have to cut the inlet manifolds about a lot .... and with the throttle inclined outwards the fuel pipes would just about hit the inner wings and other bits hanging off them ... so it would turn into quite a job. Bearing in mind I don't want much more than 180bhp - as I've seen transmissions break at power levels above that - I think I'll stick with what I've got for now!

Finally - cam pulleys, question for Les: you mentioned you made up some bigger pulleys. Are they simple flat pulleys, or do you have a vertical face on either side to help guide the belt? I've made some pulleys for mine, but smaller to allow for the shorter belts, and have a vertical face to help guide the belts.... I'm wondering if the belt edge rubbing on that face is making it wear quicker?

Anyway, that's about enough for now, hope this answers some questions and provides some info.

Cheers for now,

Alan

[Spyderman]

Hi Knight try this site if you haven't already
www.ricola.co.uk
Richard the guy who's site it is has done a couple of Alfa lumps on to VW boxes
First was his 356 Speedster (which he eventually fitted with a Scooby turbo motor), More recently he did a Karman Ghia with a 1.7 8v motor.


Myself I have a M&W 550 Spyder with a 1.5 Sud Sprint engine and box
http://brookespeed.v21hosting.co.uk


Guy

[alfa]

Hi Spiderman, had a look at your spider......looks like the 1.5 sud motor fits a treat in there!.....here is a pic of my fugitive....



out of interest what did you do for the exhaust on your 1.5 sud motor?.....mine is a pile of crap, and I intend to fit a standard manifold system, which will be a single outlet pipe. what exhaust primary diameter size did you use?.....have you had it dynod?.....do you know of any performance air filters that will fit straight in the standard steel box?.....such as K&N.....as the paper filter I currently run are notoriously restrictive......

[Spyderman]

Currently I use a slightly modded std bore 1.5 ti manifold. On the back of it I use a Supertrapp silencer. model 447 shorty I think its called
About the only thing I could get to fit under the back.
Not quiet though. But does make a great noise

Air filter wise I had a couple of separate foam element filters, but this year I put on a stock airbox with a std air filter

Poss K&N may do a replacement element
http://www.knfilterchargers.com/search/appsearch.aspx

the search allows you to put in dimensions

[knight]

Spiderman......I have a question for you.....could you do me a massive favour and measure the primary outer diameter of your standard alfa-sud sprint exhaust manifold?.....I have been told the 33 1.7 8v item will fit, but I just want to check the primary diameters are comparable. the 1.7 8v is 42mm OD.....whats your 1.5 sprint item?......and have you ever had the thing on a rolling road?.....if so what did it make?

[Guest]

Dropped you a email but

Just measured the O/D of the primaries out of the heads. The manifold is 35mm O/D
As regards power output I would guess if it was in good fettle I would be seeing a few BHP up on the standard 95BHP they come with. Never had it on the rollers to be sure.
Only paid about £100 for the engine, gave it a decoke and chucked it in, and that was back in 92/93. When it dies just get another

[Spyderman]

Forgot to log in when I posted that reply