Hi, yes it's easy for engine development costs to sore out of hand, I originally was just going to drop in a gsxrk5 inlet cam, give the head a mild port, install a thinner h/gasket.
now I've spent around $5k on various mods , a large chunk on engine machining costs, though it has evolved from a simple to much more intensive development.
and still the only non suzuki parts are the adjustable cam sprockets , kelford cams, v&h std size valves, plus the extactors i made., !
so I've been doing some testing prior to it going to the dyno tuner next week, Bretts bike is supposed to be done today / tomorrow.
I've tried running it without the pcv , on the reflashed ecu that had a tune to suit stock mtr with a pipe, it does run better than the pcv tune at above 4k rpm, but still very lean - as it won't continue to pull hard thru to rev limiter in top two gears .
but its definitely going a lot harder than the previous cam set-up, I tried to gauge the mixture via some new plugs
but the ceramics are just as white as new, earth arms have a nasty overheated look about them.
the rings seem to be nearly run in, compressions still nice and even, so I did some work on the forks to get ready for the hillclimb, tried to run both the hyper-pro f/springs in conjunction with the k-tech valves and their compression adjusters, those hyperpro springs are probably only any good on a smooth racetrack, as they are just too stiff for general road riding. so I've reverted to one stock/one hyperpro springs, put 5 weight f/oil (10 weight prev) and a little more preload than previously, does seem a better set up. ive carried out a careful wheel alignment, rear wheel was 3mm offset to front, so ive ground l/h wheel spacer, and put a 1.5mm washer on r/h side, wheels are now within 1mm of true alignment.
hanging out for that engine tuning now.....
so went for a ride to try out some suspension setting changes - came back home, smell something odd, coolant getting ejected - blown headgasket!
so looks like I'll be removing engine again
luckily I do have a spare gasket - just it's a stock thickness item, so compression will drop back to 12.5:1.
and it will require retiming cams again!
surely can't have much more go wrong with this rebuild
I better recheck everything just to be cautious, as I'm determined to go in the hillclimb, im still awaiting the dyno tune, as this is whats needed to get the thing running right, my fault on the blown gasket as its severely lean and needs some ignition advance taking out of it to run without detonating.
What fuel are you running in it? Even your "lower" 12.5:1 would be pushing it on NZ petroswill.
it's not a bad thing till you throw a KLR into the mix.
those cheap ass bitches can do anything with ductape.
(PostalDave on ADVrider)
I ran 95 in it stock which was 12.2:1 comp ratio, but when it was reflashed to suit the 1st extractor exhaust, the guy gave it an aggressive ignition advance setup to aid the torque delivery. there's plenty of stock bikes running 12.5:1 comp ratio, some new 1k bikes run 13:1 stock now.
since I've been modding eng it's been run on mobil 98 octane, but its my guess its the ignition advance in combination with the very lean fueling causing the detonation.
if I slowly roll throttle til it's starting to pull into powerband I can then give it a heap of throttle with no additional detonating.
I was running between 12.9:1 and 13:1 comp ratio, but its the reduced squish figure I'll miss with the stock head gasket, it's 38thou with it, and 26thou with the thin gasket.
it slows the powerband engagement , makes it softer hitting, compared to the reduced squish figure.
Most vehicles in search of better emissions and lower fuel economy are pushing high compression.
My Ducati is 13.2:1 and recommends 95 or 98 RON. No noticeable difference between the two fuels in real world use - well other then my wallet.
2018 GSXR1000 13.2:1
CBR100r 13:1
V4 Ducati is running 14:1
1290 Superduke 13.6:1
it's not a bad thing till you throw a KLR into the mix.
those cheap ass bitches can do anything with ductape.
(PostalDave on ADVrider)
no my gsx doesn't have knock sensor, nor does the gsxr1000, I've dropt the mtr out , removed head, got Taylor automotive to do a minimum plane on the head (1 1/2 thou) then I lightly lapped valves to see if any of the seats warped , all seems good.
so next I'll rebuild the cyl head and reinstall the eng and hook it back up , should be ready by Thursday, Bretts doing my brothers bike 2moro, then I can finally get it tuned and get some tyres fitted for the hillclimb.
so got my bike back together and then managed to get it swapped over for tuning on brents dyno, probably be ready next week he said.
Brett has started tuning my gsx-s, but its still detonating under load around 4-5 k rpm, he's taken 7 degrees timing out but its still there, I did take it over with 95 octane gas
I've just got hold of some cr10ek spark plugs to help reduce it, and I got hold of phill tainton @ptr racing in aussie ( he has a 1200cc raced gsx-s) he thinks I should be able to remove more ignition advance without hurting the power , so I'll swap the fuel over to 98 and install the sp/plugs, Bretts got a couple more tweaks he can try also
so hoping it will be rideable by early next week.
I've got another thin gasket on order, but it will be too late for the hill climb, shame as it's noticeably down on grunt without it, 172hp will have to do till after the hillclimb.
Have you replaced head bolts at any stage ? Worth doing with your new gasket - they stretch.
I haven't replaced the head bolts yet, there is 10 x 10mm fine threaded bolts holding down the head, the stock torque setting for the gsx-s is 23ft lb +60 degrees.
this is in effect less than 40 ft lb, the stock bolts are capable of a lot more torque, I'm setting them at 45 ft lb
I've carried out dozens of head gasket replacements on cars that they suggest replacing head bolts, for some customers I've replaced the bolts, others not, haven't noticed any difference, or failures.
bolts obviously do stretch with loading/ torque, my Carrillo conrods cap bolts were set by measuring how much stretch or length was gained.
I'm aware it's not exactly the modern practice, but at that low amount of torque I'm fairly sure they aren't going to fail
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