All my engine rebuild & head work was done by Alan White at Autotechnik in Southampton (02380) 666200 Very reasonably priced work & a lot of attention to detail..
I have altered the graph above to show a better scale. Also, I have a link to a hires version... Hi-res Dynoplot Smithy, Do you still have the standard size inlet valves or the digifant ones, and is your exhaust a standard driver one or is that digifant as well? Cheers Edited by: atkinss
atkinss, My exhaust valves are standard size, but thats the same size as digifant, the head is essentially the same spec as tubs old k-jet GTi apart from the fact that its got the DIY port job on it and the ports are matched. Im running an 8v digifant, manifold, downpipe and system. It didnt make quite the at the power of Tubs K-jet there, not bad for what it is though! Interesting to see that my motor makes peak power around 500rpm higher than tubs K-Jet, which is probably mostly due to the headwork. The Kent cam should make it rev a good bit further before tailing off, hopefully it will shift peak power into the 6-6.5k rpm area as well as increasing the overall power Edited by: smithy
The Kent GS2H cam with a Vern alloy pulley are the dogsbolx, they kick in just over 2700 and pull all the way. Combine this with a p&p head and the dif between standard and tuned is very noticeable.
Can't wait then... Has to be the cam to go for! According to the Kent Cams website, the powerband is 2-6.5k. Does anyone know exactly what comes in the kent kits that can be fitted to the head without removing it. The kit comprises... 1) Performance camshaft 2) Heavy duty cam followers 3) Performance valve springs 4) Gaskets 5) Oil seals 6) Cam lubricant So im guessing everything apart from no 3.? Is it recommended that the springs are changed? Cheers
Yeah.. all but the valve springs. And the driver will make peak power at higher revs than the GTI because it has shorter stroke.
The springs are a seriously worth while investment if you want to take the engine to a further stage and rev to around 7500rpm plus, not essential, but a good idea. Kent valve springs come reccomended , the spring rates of them over standard are usually very good indeed, progressivly wound to. Edited by: madmk4
I think i'll keep the standard springs initially then, to avoid the extra cost of removing the head. Whats the general opinion on getting a kent vernier pulley as well? Are they required? Would one be worthwhile? Cheers
Their is a way or removing the valve springs with the head on....You need a handy tool... Compresed air fitting into the cylinder via the spark plug hole and a tool which bolts onto the head and levers the spring caps down, allowing the removal of the springs and stem seals if reqired....Saves a bit of time...I had mine from Klan tools via a Snap on dealer... The verinier pulley will only be needed if the new cams max lift timing is not the same a the standard cam, for example Pipers BP285 peak ex/inlet lift occurs at 106deg atdc, the standard is around 112/113 deg. This cam would benifit from a vernier. Most of the road Schricks and Newman cams are timed at the standard 112/113 deg in most cases removing the need for a vernier.... Edited by: philip walker
I've just checked the Kent Cams website and it says the GS2H cam has valve timing of 110 degrees, so being only 2-3 degrees different to standard, compared with 6-7 in the piper example above, is their going to be timing problems without the vernier? Thanks
In the real world you probably would not notice...Only on the dyno you may show a slight gain a with the vernier.... Edited by: philip walker
The bloke who did mine said i would probably see 3bhp at most from a vernier on my old car/cam... and i trust him. He built the Orange Twin engined Renaaul 5 Turbo we must have all seen!
I wasnt going to bother getting the kit, just the camshaft, do you think it will be ok on standard tappets? (new) EDIT: by the way Tub, the 1.8 driver engine has the exact same stroke and compression ratio as an 8v GTi. Edited by: smithy
Will be fine.... I look forward to hearing how it goes...... I will be honest & say im toally sceptical that a 270 degree cam gives 15BHP peak extra over a standard I remember some while ago "The Golf" mag tested a Piper 270 & Piper 285 on an 8v with a dyno proven 115 @ the flywheel. (filter/exhaust) The 270 raised this to 120 & the 285 to 123BHP peak (with the power holding on better at the top) As far as I can see there is no way a mild cam alone will give 15BHP..... [:^(] Does anyone care to disprove me?
is it worth doing some thing like a P+P on an engine thats done 120,000+ miles, (like mine!) would it make a lot of difference, or such a little difference that its not worth it, when you talk about modding the air box what do you mean? cheers, tim
A 270 cam does give fair gains over a standard cam and they are certainly noticeable. I have driven a 8v 2ltr with both a standard cam and a 270 Kent cam and the power band change was very noticeable, the car had power far further up the rev range, you could open the throttle up at around 3000 rpm and feel the car pull all the way to 6000 a standard cam does not do this at all. An 8v has loads of grunt at the low end, a high lift cam allows the power band to be a little longer and go a little higher. I would recommend one.
Chris.. i have the RR graphs to prove it mate.. done by a very trustworthy tuner done on the same day on the same rollers with each run within a couple of hours of each other. Smithy, you sure about the stroke and conpression..? just remeber reading they were different in the haynes book of bollocks.
All 1.8 litre 81.0mm bore, 86.4mm stroke 1.6 litre 77.4mm stroke All 1.8's have 10:1 compression, except RP engines which are 9:1 taken from the aforementioned Haynes book of testicles I'm running a Piper BP 270 in my 2 litre with a polished and ported head and manifolds, but a standard valves....seems to go well, runs out of puff at 5500....really need big valves. Should get it on some rollers this coming weekend....see what the score is. Not used any other cam so i can't compare, unless you want me to just blurt out some testicles i read in a magazine Edited by: g60 pb
