Hi, Looking for ppls thoughts really. I've had 2.0 8v in one of my roccos for years now and last year changed from carbs back to original injection.. The engine basic spec is, 2.0 3a bottom end using 3a dizzy. Lightened flywheel. Tsr pack c head with a tsr 102 cam which i believe is a non hyd head Accompanied by a lovely Fm close box out of a mk1. Now i used to run this engine on twin 40s and it ran great, never on the rollers but tweaked myself. It was rapid! And idle was good and smooth,maybe 900rpm. There was no popping or spitting from the exhaust. It just ran good. Then.... i wanted to be sensible and daily the car so i switched back to factory k-jet. I now notice that low end is far poorer than carbs and the exhaust is spitting and popping on idle. It just generally drives crap at low revs and stop start city driving(sub 2000rpm). So I'm wondering if this cam is really suited for the kjet system? I have read plenty that kjet runs poo on big cams. I have set ignition to factory and played with more advance. Not much different. No vac leaks. Fuel pressures are all ok to spec. Because this is a non hyd head does that mean i cant just slap a gti cam in? Head is 026 103 373 f Whats peoples thoughts/ reccomendations? Thanks
Lambda dash reader useful, IMHO. Could be lean low down? All my rally cars have one, more useful than a rev counter IMHO Jon
I think a 102 is around a solid lifter 272 profile, so pretty mild, and should run with ease on kjet if set up right. You'll need to check valve lift @ true TDC to get the cam timing right. Ignore the crank pulley marks as they're often out due to the damper twisting on the rubber over time...use the dimple on the flywheel visible through the inspection hole in the box. The Advance/Retard markings on a vernier are meaningless unless you know your starting point. When you skim the head or/and the block the zero setting goes off the mark, so the cam timing won't be where you think it is. And there's no guarantee the lobes will have been ground aligned with the zero datum. You'll need to measure the lift @ TDC on number 4. A 270 ish cam is likely to be around 60-70 thou. Set the inlet to 15 thou more than the exhaust. So if equal lift is say 65 thou, set the inlet to 72-73 thou and the exhaust should be around 58 thou...depends on the profile. Kjet does run poo on big cams...290 ish plus, but a 270 will run nice set up properly. Check the fuel and control pressures. Only use a Bosch fuel pump, most generic ones are junk and old pumps go weak with age....pressure is critical with K-jet.
Thanks for the detailed replies. I know for sure pressures are good. Injectors are new too. Both rear fuel pumps are new bosch items so i am thinking check the cam timing and i have an afr gauge stashed somewhere i can fit. Another related question... Is there a cast 6 bolt style zaust manifold with a lambda boss that may fit? I have a new 4-1 mani with a boss but they seem to cause a bit drone and fitment with steering boot is poo... Thanks.
No problem at all. I can walk you through the cam setting up process when your ready. You'll need a magnetic stand and dial gauge plus a long thin pointer to go on the cam buckets...and a solid flat plate that can bolt to a cam cover stud for the stand to sit on nice and ridged. I'd check the control pressure of the warm up reg too as they can play up. Sounds like you have a LHD fitment shiney special off eBay. A mk3 8v around 92-93 'may' have a suitable manifold and downpipes if it's from a short height block, but not totally sure. Finding stuff now is getting harder too. For a Scirroco a mk1 Golf Ashley manifold should fit. Cheap enough new direct from Ashley and being mild steel 'ring' less than a stainless manifold. Easy enough then to weld on a lambda boss off an eBay supplier or maybe Ashley stock them. No huge power gain over an O.E manifold and downpipes at your power level, just easier...can pick up a couple of hp though. I'd probably ditch the 3A dizzy too and use a kjet GTi one. Won't the 3A be just a phase sensor too and run off a mk3 ecu?...that could be part of your problem. You'll need an adapter ring from memory as I think the dizzy hole is bigger in the 3A block.
TSR engine your spec, can make quite a bit of improvement at WOT. To see the real benefits at all conditions, you need to switch to EFI injection and a tuned ECU. You know how fast it is, well it would go even faster with EFI. In fact, way faster than a good working KR motor till 6000 rpm, with superior mid range passing power. I have tuned a few of those combinations. Do the checks on the cam set point as Jason was suggesting top ensure there are no restrictions on cylinder fill when the engine is at different operating points. You cannot use factory tune up specs for this engine. You need a MK1 Golf exhaust system with a lambda bung welded on to monitor your lambda control from the carbs. I can say your target lambda will need set at at high load from 13.2 to 12.9 near the redline. Your clock work dizzy will have to set in a compromised position, to have little or no knock at light to high load low speeds, which will compromise the advance required at high load high speed. Your idle should be consistent between 800 to 900 rpm once the idle mixture and base throttle angle is well balanced between carbs. A piece of hose can be use to listen by air if you are old skool or a carb sync tool. Good luck with it.
Ok. Will probably just buy a boss and use my existing mani then, seems less hassle too. Also just checked my dizzy and the part number comes up as dx dizzy - and it has the adapter ring which i never noticed before so the block must of been used for mk1/mk2 before me.bonus! Will take u up on the help for setting up the cam w/vernier. I've not really come across a sticky on this yet... Not sure when i will get round to it though as currently going through a g wagen restoration which is taking up all my time.
Thanks! As above, turns out my dizzy is dx not 3a I think maybe my post was a bit confusing so to clarify, engine used to be running carbs however now is back to factory k-jet system. I am interested on the EFI side of things. Ive always wanted to have a go at megasquirt or something but never got round to it and an 8v converted seem rare these days. Also i do like to throw money at my toys. I have checked out your work with megasquirt, great reading For now i will fit a boss for my afr, set up my cam properly and check/monitor my system/control pressures.thanks
. No problem at all. I've covered it a few times in various threads but no never done a sticky for it. That's great you already have a DX distributor as they have a good curve and can be tweeked to work well in many applications.
