Read a thread a while back that listed the duration and lift of factory VW 16v cams. Anybody know the numbers? Search isn't working for me [:^(] KR Inlet/Exhaust ABF Inlet/Exhaust 9A(6A) Inlet/Exhaust
This might help http://membres.lycos.fr/philippe840/clubabf/GolfGTI/camshaft .php http://membres.lycos.fr/philippe840/phpBB/viewforum.php?foru m=7&191 Edited by: G_V_K
in my excitement didn't spot the fact that the table above isn't complete.. anybody know the numbers for sure? I want to know what likely gain will come from replacing inlet with a stealth modified exhaust cam on my KR engine. From what I can gather in the tables above, I will move from 207/9.6 (duration/lift) to 215/10.21 intake. Would I even notice that on the road? Doesn't seem like a lot to me... edited to add: when comparing cams, which numbers for duration do you use? Edited by: Tanner
Im led to believe all the zorst cams are the same.Only the inlet cams are different and the kr inlet cam is the best. Ive used a kr exhaust cam modded to inlet cam with a hotgolf chainwheel(pm me if you need 1).It makes the car alot more driveable as it smooths the torque curve out by bringing power in around 3k instead of 4k
Yeah hidro, sorry mate but already knew that abf is no advantage over kr. know exhaust cams are same too. vortex is quite good for that sort of thing. flusted - sorry to sound bit confused but how can a cam with longer duration and more lift bring the powerband down by 1000 rpm? I'd have thought it would raise it...
Dont ask me Im just reporting back how the car feels! at a guess where its not a big change in lift and duration it slightly improves it instead of allowing to much air in low down and ruining torque? Guna get my car stealthed in july and try and get gary to put power graphs on his site to compare!
hi mate.. i think its to do with the stroke of the ABF and not the cams. it has a longer stroke so makes more power lower down (I THINK)
Nah... bore and stroke is the same. The ABF head is slightly better because it has bigger exhaust valve seats than KR/9A/6A. The valves are the same size, but the seats are bigger, allowing a bigger flow area around and behind the valve.
The EX valve seats are the same 27mm on all head castings. The exhaust valve on a ABF/ACE/ADL is 27mm vs the 28mm found on KR/PL/9A and 6A heads.
Got 26.99mm on exhaust valves (pt# 051 109 611B) from 051 103 373 D head from ABF and a ACE unit I have here and 28.01mm on valves (pt# 027 109 022G) 027 103 373 E head from 88 16v. By having 27mm EX valves the valve does not shroud the seat (vs 28mm unit) which increases flow out of the combustion chamber. Also did some cross referencing as I remember GVK saying he used a KR cam set on an ABF style head on his 9A. What I found was VAG did this with the later '94' 9A engine in Corrado that had a '051 103 373 D' head on by using one 027 109 021 AL(IN) and a 027 109 22G(EX). Therefore there is no reason why a 027 109 021 AH inlet unit cannot be used on this head an not produce great breathing results. A few posters on here have already demonstrated this.
Sounds like you're sure then ... I sit corrected. Give me a minute and I'll stand up. Maybe I got confused (easily done at my age) I wonder if it's worth having the standard KR 28mm valves ground down a bit then, or would that weaken them do you think? It's going a bit off topic, but any opinions on that... or just buy the stock ABF ones and re-seat them in a KR head. In theory, the KR ports should flow better, as the later heads have less meat in the casting (different shape of water jacket to improve cooling and reduce pinking), so a KR head with ABF exhaust valves could be the best possible 16v head, without spending megabucks on bigger inserts??
051 109 611B is 97.95mm tall and 027 109 022G is 98.2mm tall and carry different collets. Do not forget that. You can do that mod by obtaining a late 051 103 373D head and installing to your motor hopefully with the right set of cams. Ahem after you get your man to do his art.
Ok...so in between the forest of part numbers, that tells me you need to match the head type to the valves for that head. I wonder if the 'oversize' valve was a way of stopping blowback through the valve at low revs... (i.e. a bottom end torque improvement) for the KR, and they discovered the 2.0 didn't need it.?
i have gas flowed ported and polished all three variations of the 16 v head ,run them all with the same cams. and found them all give similar power, but on the road i found the 027 thin inlet delivered the power more agresivly than the others and felt the best , and the abf head felt the worst, all running on schrickt cams and standard springs . just a opinion on personal experiance,
