Meow

Put my car back on the road last week after winter hibernation and chaged the oil as EFA suggested. its only taken me 5 months i know ... 😬 what can i say, it works, brilliant! thanks... Been testing it all week and seems fine with smooth revs right through to 6750 rpm, no valve bounce.. Saved me a whole chunk of cash ... Thanks for your help. Rob

Will do Al. If I have to change the lifters then i was just going to get some new standard ones from Vauxhall. But if i can get some slightly uprated ones then maybe i should do that. Ill try the oil change first then see how i get on. Hopefully it will solve all my issues Rob

Will give that a go first and see how i get on. Thanks for the advice. Rob

Hi EFA, I actually had 10w40 standard semi synthetic GTX oil in there at first.. The cam spec is as followed: AST15 SPORTS ‘R’ Hydraulic. Power Band: 2000-6500 Cam Lift inlet/exhaust: .295’’ Valve lift inlet/exhaust: .498’’ Duration inlet/exhaust: 272 Degrees Timing figures: 31/61 61/31 Inlet exhaust at full lift: 105 Degrees Valve clearance inlet/exhaust: .000’’ Valve lift inlet: N/A TDC Exhaust: N/A The springs that kent supply with this are the VS37 type with the following spec: SINGLE SPRING Installed height: 1.497”/38.00mm Nominal solid height: .905”/23.00mm Nominal I.D: .836”/21.25mm Diameter O.D: 1.147”/29.14mm I also have a vernier on the cam and have ensured the inlet is fully open at 105 Degrees (measured with protactor against TDC). Hope it helps. I did think about swapping to double springs as thought it might be the problem but all other blydenstein conversions dont suffer the same problem... Thanks, Rob

Hi Guys, Thanks for your advice. EFA, I upgraded the head for a Blydenstein conversion and also upgraded the cam to a ast15. Since then i noticed a little vlave bounce (not allways) at higher RPMs typically just over 6000 rpm. I thought it was springs to start with but after talking with kent cams they said it was either oil related or a hydraulic tappet. So i swapped the oil for comma synergy 5w40, which did improve the issue a little but not completely solved. So maybe i should try Mobil 15w50 like you said before replacing the lifters? I didnt think about taking the cam out, thanks for the tip ... Epimetheus, I thought about stiffer springs but Kent just said its probably lifter related if anyting beacuse they had never had any problems with the uprated springs that go with the ast15. Al, i had the car at track n road a little while back. They couldnt do a decent power run because they were worried something might go bang as it showed what we think was valve bounce, not for every run but enough to worry. Steve did mention though that the engine had a bit more to come as i had them 3D Map the ignition. Still made a huge differance to the drive of the car. So im trying to resolve the issue then go back to Track n road for a final couple of power runs.. Help very much appreciated... Rob

Hi Giles, Good one, dont want to forget that 😳 Thanks, Rob

Hi Giles, Thanks for that. Think i will just go and buy the head gasket and bolts. I have all the tools to put the head back so might as well go the whole hog. Just trying to be a cheap skate Can you help me out on the wheels front? I really like the MB style wheels so want to swap my steel whellers for some... Thanks, Rob

Im planning on replaceing the Hydraulic lifters in my 1600 vx soon as at high rpm i get a little valve bounce (thiner oil helped this a little but not compeltely solved). Im wondering if i need to change the head gasket as what i wanted todo is to just un bolt the head, take the cam holder off the head, replace lifters then put back together (with new head bolts). Do i really need a new one? Im also thinking about upgrading my wheels to Mike Barnaby style but wondered what size i should go for? Would i need longer studs as well (got steel wellers at the moment). Thanks, Rob

Been doing some digging around and it seem like kent cams may have a double spring set. Looking at the options for the AST15K cam, you can either use VS37 (single spring that i have) or VS38 (Double spring). Only thing is that they have different installed heights. Does this matter or is it ok? Would i need to change anything else or simply replace the springs? Thanks, Rob

Tried mc millan but no luck, they only focus on graduate spec cars. So im stuck now. Not sure who to approach about getting a uprated set of valve springs (double springs maybe) for my little vx. Any ideas anybody? Please help ☹️ Rob

Hi Ian, yes still has the standard hydraulic lifters. Not really sure how to approach this one. Spoke to Kent Cams today and they didnt really have a alternative to the springs that i have. I also spoke to Ivor Searle (the guys who did my head work) and they aslo didnt have any alternative. All the conversions that they have done i.e. with bigger valves and the AST15 cam have been fine. So im left wondering is it really the springs or something else and how will i tell ☹️ Rob

Just out of interest do you guys know of what other component failure may give similar symptoms to that of valve bounce? Coil lead, distributor (i cleaned this though), spark plugs? I mean all the other members with the Blydenstien issue dont have the same problem. Rob

Brunel. Thanks for the link. Will give them a call. Ill also try Andy McMillan, i must be able to sort something out from these guys... Thanks, Rob

Have the standard bottom end so need to be a little careful. Maybe a call to Kent cams is worth a try... Thanks, Rob

Hi Peter, Thanks for the advice. I think there is a bit more to come out of the engine at the top end like you said. The set that is in their was supplied by Kent cams along with the AST15 cam that i have fitted. I think these are really designed to be used with the standard valves. As mine have been enlarged then their mass is more etc.. Do i need to be careful uprating them too much? I mean will it bugger the cam if i put some firmer / uprated springs in there... Thanks, Rob