Felicia bike carbs

[jonnycilia]

Hi i would like to know how to install bike carbs on a skoda felicia carbed engine. And what manifold do i use ? And what modifications do i need to make ?

[MotorsportFinland]

1. Remove the original inlet system from cylinder head.

2. Fabricate new flanges and weld short tubes into them, or if you are able to turn ones from a single pieces its even better.

3. Attach bike carbs using either their original rubber grommets or just pieces of rubber hoses, tighten with hose clamps.

4. Fabricate a new linkage for the new carbs and remember to adjust them that they are synchronized properly.

5. Fix a proper air filter. You DO need it.

6. Start the engine, spend dozens and dozens of hours to set the mixture right.

7. Buy a A/F ratio meter, NOT the cheap chinese one..

8. Spend yet a lot more hours to try set the mixture right.

9. Go to a rolling road specialist.

10. Drive happily since its finally ready..

You can skip phases 7 and 8..

☺

Edited 11 September, 2016 by MotorsportFinland

[jonnycilia]

Wow nice guide. Thanks alot the only bit that i didnt understand is step 4

[jonnycilia]

What hp increase will i expect with bike carbs ?

[MotorsportFinland]

You will have to synchronize multiple carbs so that they work ie. open and close simultaneously, otherwise one or some cylinders get leaner/richer mixture than others.

You will get about nil more horsepower with bike carbs compared to well working standard carburation which is set right. You DO get beefier sound and mpg goes worse since you will open throttle more listening that sound..

I dont think you will gain anything by just changing the carbs without other modifications to the engine. Are you thinking to put them to 1,3?

[jonnycilia]

Yeah but if i get no gain im not putting them. Im wondering what else i can try

[MotorsportFinland]

What do you want to do? Do you wish to have a little sportier engine, or get brutal power unit?

Do you have a spare engine to tune or just this one you will use in everyday driving? What kind of money are you thinking to be able to spend on modifications?

 

Perhaps smoothing the ports, a valve job, skimming the head, aligning inlet manifold to ports, a good tubular exhaust manifold and a sportier camshaft should give you a good start. Lightening the flywheel will give you a bit faster revving engine characteristics, and polishing crankshaft&conrods will prevent oil clinging on to them too much (no extra rotating mass).

Edited 12 September, 2016 by MotorsportFinland

[jonnycilia]

I want a bit of a sporty engine. Dont want to spend big money. Are tubular exhaust manifolds available for felicia or will i need to get a custom one ? With what can i upgrade the valves ?

[MotorsportFinland]

Here is a one ready bolt-on option:

 

http://www.speedpro.eu/vyfukove-svody-sport-skoda-favorit-felicia-p-382.html

 

For valves you can reshape and polish them, then have the valve seats cut either in three angle or radius shaped.

[jonnycilia]

Oh nice. Upgrading the valve springs to something aftermarket does it make any difference ?

[KenONeill]

Oh nice. Upgrading the valve springs to something aftermarket does it make any difference ?

Only if you buy forged racing pistons and rev above 6_000rpm.

[jonnycilia]

I meant the valves not pistons

[MotorsportFinland]

If you want to safely (continuously) rev the engine over 6000 rpm you will have to change springs to avoid harmful vibrations, and also need forged pistons since cast pistons will eventually crack due stress.

 

I dont recall are the pushrods all steel or are they different between inlet and exhaust. It might be better to run all steel in engine which is continuously on higher rpm..

Other thing is to be considered that raising too much useful rpm will cause problems when using std transmission ratios -> no low end torque + large gap between gears =

Edited 13 September, 2016 by MotorsportFinland

[KenONeill]

I meant the valves not pistons

I got that; I meant that the only point to uprated valve springs is to allow you to rev higher before valve bounce and float set in, and if you want to rev that high regularly then you need (expensive) forged pistons and a balanced set of crankshaft, conrods and pistons as well.

[jonnycilia]

Ok i got the point thanks guys

[jonnycilia]

My pushrods are not all steel

[jonnycilia]

I might aswell do all this when sometime i rebuild the engine maybe

[octyal]

What is the engine going to be used for? Pure racing engine, or just fast road?

[jonnycilia]

No just for being a little fast for roads as you said

[jonnycilia]

Hi guys a bit of question out of topic. The front grill of a 98 felicia will fit to my 2000 prefacelift felicia in any way ?

[MotorsportFinland]

Hi guys a bit of question out of topic. The front grill of a 98 felicia will fit to my 2000 prefacelift felicia in any way ?

The grill itself might but aren't the bonnet and headlights different?

[jonnycilia]

Yeah they are different. I was searching for an aftermarket grille with a mesh instead

[KenONeill]

Yeah they are different. I was searching for an aftermarket grille with a mesh instead

In which case the critical points are height, width and rake angle, and I'm sure someone with access to a pre-facelift car can help!

[jonnycilia]

I would like to buy an engine 2nd hand. And rebuild it with better parts myself. But i havent got an engine jack, is the engine very heavy because maybe i got a friend of mine that would help me lift it to my garage. Then pay a mechanic to install it for me when its all done