Lack Of Power

[carmike 4]

Hope someone can give me pointers here. I did a deal couple of months ago with one of my classics and took a nice 1.9 GTi against it as I fancied owning one again. On doing deal the 205 dropped a cylinder but I still went ahead as shell is very good and has good history etc. I moved a plug and the duff cylinder followed so fitted new plugs and adjusted idle as it was near 2k. Now after a few road trips I cant help but think the performance is rubbish, plus there is a cam type rattle mid revs, unfortunately I have found out its had a new head as old one was porous . TBH I think I have had ma pants pulled on this car as the drivers window was held in with wood and various bolts from engine were missing, manifold is cracked and the k&n was taped onto another hose above exhaust manifold. I have rectified all bolts and sourced and fitted original airbox and hoses with k&n element, new window glass channel and sorted wiring issues.

 

My questions are would a 1.6 head make car slower?

is there a casting mark to identify 1.9 &1.6 heads?

Does anyone know why when you floor my car it has performance of a 1.4?

cheers.

[kyepan 291]

You could give it a quick compression test to give you an indication of how healthy the rings and valves are.

 

If it's reasonably normal start looking at the simple stuff, is the spark good, is it getting enough fuel etc.

[DamirGTI 327]

1.6 and 1.9 heads are actually the same (apart from very early 1.6 heads which had smaller valves) , but the camshafts are different .. haven't tried driving 1.9 with 1.6 cam fitted but people who did say that it kinda kills performance/feels flat .

 

No casting marks or similar on the head for ID , but as said there really isn't any major difference 1.6 vs 1.9 (again apart from early 1.6 head) .. valve size is the same on both , only difference is camshaft and combustion chamber volume (32cc for 1.6 and 34cc for 1.9) .. camshafts have paint ring markings on them so they can be identified , difference in the combustion chamber volume is just 2cc +/- really not much so you wont even feel it nor it will have impact on performance as such .

 

As Justin said - do a compression test , could be tired/worn out engine .. apart from that check ignition and fueling components ... from you're description sounds like poorly maintained engine , if the engine is otherwise mechanically sound , good tune up should restore it's performance .

 

Also check for possibility of mixed engine management components using 1.6 parts on 1.9 engine (AFM/ECU/injectors/dizzy) , while this may not have so much impact on performance it will have on tuning up the engine so that it works/runs smooth .. on a long shoot , if it's so drastically slow , you might even have wrong gearbox if it's an ex "bodge boy racer car" .

 

Out of curiosity , as an first attempt - try to advance the ignition timing a little bit , and see what happens .. if it had k&n filter stuffed above the exhaust manifold this decreases air density massively because of drawing hot air thus the ignition timing needs to be run retarded to stop it pinking , i imagine quite a lot retarded .. if you haven't yet replace with OE inlet system (air box/pipework) and advance the timing up to the point till it starts pinking under load in high hear then once it starts pinking lightly just back off a little bit on retard side .

 

Dunno what you meant by cracked manifold ? exhaust one presumably ? if so that is very common , and also causes "valve rattle" kinda sound .

 

D