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Discussion Starter #1
need advice ! have just bought a 1985 gtv 2L want more power out of it with out using a turbo looking for about 120-130kw if possible what mods does anyone recommend ,engine needs a rebuild any way ,or is it easier to do a engine conversion ???
 

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1966-2013
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Cams, high compression pistons, aftermarket ignition, ITB's and programmable EFI will carry you quite a long way toward and a bit beyond that goal actually.

Seek out msiert's 'black spider project' up in the spider subsection for an idea of how gnarly it can get with the 2L.


Now take into consideration that if you're looking for a cheap way out, it ain't gonna happen.
 

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thanks for the info Tifosi, to keep the price down my alfa mechanic suggested maybe just reco the bottom end and work the top ??what mods and specs would you recommend for that and what increase in power should i expect ,also do i go a set of webbers or is there something better ??? confused need advice from some one whos done it all before my mechanic is old school whats to do every thing standard so need good advice ..cheers
 

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Well, if you recondition the bottom end, which isn't a bad plan, then likely pistons and liners would fall into that bit of things.

The L-jetronic pistons run 9:1 compression. (presuming you have an L-jet anyway)

For a little less than what it costs to replace them as a set you can get 10.5:1, or, for just a little more, Motronic pistons and liners which are 10:1. (if your mech wants to take the stock route, go with the Motronic as they were stock, just 5 years later than your model and will direct fit with no issues :) )

Again, in the stock aspect, you can get performance intake cams made for use with a VVT (with or without exhaust cam as part of the package) or you can go to a set of SPICA injected performance cams and lose the VVT all together. (power will be there, so will a slightly lumpy idle)

If you want to spend the $ on weber conversion, (around 2K USD for a package not including manifold), it'll work and get you some power, but for the going rate of that conversion you can get very close to what it costs for ITB's and aftermarket programmable EFI which can get you more power yet. (no one sells a complete ECU, ITB, manifold etc. kit that I'm aware of, so shopping around is the way to go and can get you some decent prices. Of course going that route will allow for the purchase of even gnarlier cams as the flow limitations of the stock injection system would be done away with)

Aftermarket ignitions can be had in many flavors, all the way from the basic optical sensors in the dizzy w/coil, brainbox, and recurved advance, up to crank triggered sensor multi-coil scary spark throwing things. (it all depends on what you want to do as they all cost right around the same within reason. There's also EFI ECU's that can deal with ignition, so that might be an option too)

Best bang for the buck, top end only: cams and free flow exhaust (prolly the first things that should happen in a budget rebuild looking for some power gains)

Higher compression pistons will almost always add a bit of power, and definitely will in the case of L-jet (5-10-ish at little or no cost difference compared to stock replacement parts)

Free standing ignition, while not adding gobs of power will go a long way toward tunability, which can get you better usability of the power you have.

Oversize valves and performance springs will garner a little bit, as will properly ported intake and exhaust ports. (if you only do one side, the exhaust will get you the most gain)

ITB's with programmable EFI when combined with the above can get you some pretty significant power, but can be costly and is occasionally a little tedious to get dialed in.

It all just boils down to what you want to or can spend.

Even a header alone through stock exhaust on a good stock rebuild will make a pretty noticable difference. :shrug:

It's very difficult to say 'if you do this, this, and that you'll end up at X bhp' as it's a culmination of parts working together. (a header giving 10bhp by itself when combined with a cam set that give 10 bhp by itself does not neccisarily mean a 20bhp gain overall. It might be 10, it might be 30 as there's a lot of longhair math involved along with where the power is actually at in the curve. You might even pick up 25 up top but lose 10 down low)

You have to decide for yourself what fits your budget, skill, and desires.
 

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Hi franco975,

You didn't say where you are from, or if your car is SPICA or Bosch injection. Tifosi's suggestions are correct and, done in moderation, can increase power while retaining drivability. Some locations have smog testing issues to confront, but a search of the BB will reveal lots of information.

A quick suggestion:
High compression pistons (depends on fuel octane available)
Higher performance cams
Ported and matched head with larger valves (maybe intake only)
A high performance SPICA pump from Wes Ingram
A good header, or 1972-74 cast iron exhaust manifold
Possibly a better ignition system

Such an engine would not deviate significantly from "Original". Power increase depends upon how radical the cams would be, but a 15 - 20 HP increase over stock would be a reasonable expectation. I also suggest researching the complete modification package, rather than just throwing parts at the engine. It won't cost anything to get a discussion started and there are plenty of BB members that will share their experiences.

thanks for the info Tifosi, to keep the price down my alfa mechanic suggested maybe just reco the bottom end and work the top ??what mods and specs would you recommend for that and what increase in power should i expect ,also do i go a set of webbers or is there something better ??? confused need advice from some one whos done it all before my mechanic is old school whats to do every thing standard so need good advice ..cheers
 

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You didn't say where you are from, or if your car is SPICA or Bosch injection.
If it's a 1985 GTV 2.0, it will be twin side-draft carburettors - mine are Dell'ortos, and Webers are also common.

Depending on where you are located, your car may have shipped with a couple of irritating emissions modifications like the bell-crank solenoid which can be disconnected. Don tells me that for Aust / NZ cars, having the carbs re-jetted to their original Euro spec will greatly improve the low range torque. But it's not all that powerful a motor. Despite that the car is a blast to drive if you keep it "on the boil" and chuck it into corners. I love mine and don't really care that it wouldn't humble anyone at the lights.
 

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Discussion Starter #8
hi guys thanks for all that ,i have changed my plans slightly now i'm wrecking that car(too far gone$$$) and have purchased a 83 model with no rust good box and strong engine,my plans ? keeping the dellorto's working great got some 10mm cams and headers not in yet ,will get high flow exhaust when i fit the headers .the bosch ignition is fine want to keep bottom end standard for now so what do you suggest i can do performance wise next with out touching the bottom end and breaking the bank ? thanks frank australia
 

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1966-2013
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How non-break-the-bank you thinking?

Cold air intake feeding the carbs won't hurt much $-wise if you build it yourself, and can get you a wee bit more out of things.

Y'know, just some kind of ducting or whatnot to get air from outside the car into the carbs, and mabe with a bit of creativity, some ram effect.

A good dial in on the carbs/jetting is cheap to free if you've got talent, as are plug readings while doing the carb stuff.

The higher the state of accurate tune in regard to things like ignition timing, carbs, plugs cam lash, the better things will be in general.
 

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Hi Frank,

My first bit of advice is to find a new mechanic. If you like and trust your old one then keep him for maintenance - but for performance get a new one.

My second is that I agree with Tifosi. You have a pretty good set-up at the moment bit it is all bits thrown on bits. Get it all working as a system. Find that mechanic (maybe go to the Australian Forum section and ask in there for tips on someone in your area) and get the car dyno tuned while re-jetting the carbs. Then the carb will match the cam and header and ignition.

Once you have what you've got working well you can then tweak it a bit but I'd guess that you've done the easy bits already and the next power whack comes at a bigger $ slug.

Good luck.
 
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