simon_h Posted April 12, 2006 Share Posted April 12, 2006 I am thinking of rebuilding my VVC to 1.9 spec over the next few months as time and funds allow. I am going to have an Evo2 block anyway so the only cost difference is to buy the 82mm pistons. I already have a set of new Omega 80mm pistons so I could sell them to get a little of the money back but is it worth it? Has anyone had their engine converted to 1.9 with no other changes and what gains have been obtained? I have heard of big figures but cant find any back to back tests. Any idea what a set of new Omega's with the correct 2nd ring and pins are worth? Cheers, Simon Link to comment Share on other sites More sharing options...
Steve Day Posted April 12, 2006 Share Posted April 12, 2006 Hi Simon Great concept but from personal experience may I suggest that you proceed with caution ...I have put the scholar 1900 block conversion into my se7en - producing around 225 bhp / 155 lb ft - so quite 'gentle'...it went BANG at Bedford on Saturday - no oil pressure drop or signs of imminent failure - rod through the side of the block...huge smoke and oily mess... ☹️ I am aware of at least one other that has failed in a similar fashion (also number 2 cylinder). Only upside for me is that I still have the 'old' 1800 to go back in... cheers Steve Link to comment Share on other sites More sharing options...
silver-7 Posted April 12, 2006 Share Posted April 12, 2006 Steve refers to my 1.9 that also failed in a similar way after about 700 miles ................. ! I would be interested to hear if anyone has done desent miles with a 1.9K ?, as im not sure i really want to rebuild another and go through the pain of rebuilds ect ! Cheers Alex Steve D, sorry to hear of your problems Link to comment Share on other sites More sharing options...
rgrigsby Posted April 12, 2006 Share Posted April 12, 2006 Both Mick Smith and Johnty Lyons completed the USA tour (4500+ miles) with their 1.9K's with no problems so I suspect they can work OK. Rob G www.SpeedySeven.com Link to comment Share on other sites More sharing options...
Dave McCulloch Posted April 12, 2006 Share Posted April 12, 2006 Hmmm. 1100 miles - should I be getting worried Dave Link to comment Share on other sites More sharing options...
oilyhands Posted April 12, 2006 Share Posted April 12, 2006 I have at least 13 1900Ks in the field with no failures so far, 3 of these have been hard used in competition. Oily Link to comment Share on other sites More sharing options...
Johnty Lyons Posted April 13, 2006 Share Posted April 13, 2006 My 1900 [built by myself] witth my usuall hard brake approach gave 240BHP on Emeralds rollers and then got thrashed across America on USA 2005, 4500 miles I do not believe there is any inherant weakness in the EVO2 1900 conversion, the latest rings get round the earlier ring into gudgeon pin hole problem. my car is fully [pace] dry sumped has arrow rods and was fully balanced by WBD the aircraft balancers. 😬 Oilys comments are normally taken as gospel when it comes to Ks, this thread is No different. jj N.I. L7C AO. Membership No.3927. Se7en Services.N.I. Caterham Service Agents. www.onthelimiter.com Link to comment Share on other sites More sharing options...
Jason Plato Posted April 13, 2006 Share Posted April 13, 2006 I've done over 4000 miles , about 25 sprints, and about 6 trackdays with my 1900 K @ 245 bhp + built by Hellier (with a scholar block) . Upon strip down after 3500 miles and all those sprints - the one of the piston pins had very slight wear, the bearings were good and all else was OK . I dont think much of the variation in bore clearance with the inserted scholar liners - but it wold appear to help produce the beans I guess mnay of the problems can be like any K series - its not what it is or what it does, but more how well its all bolted together 🤔 [searches office for a bit of real wood to touch......] Dave Link to comment Share on other sites More sharing options...
simon_h Posted April 13, 2006 Author Share Posted April 13, 2006 Thanks for the info. It does appear that they are no more likely to fail than any other K. I had an Evo2 block in the last one I built and that is still going fine after a couple of thousand miles. I have no problem with the block mods at all and am doing that regardless. But, on these 240ish hp engines how much more are they giving than they did as a 1.8? If its that they were at 200hp then its probably worth the outlay, but I guess its the torque where the greatest gains will be found. I am after future proofing the engine tbh. It will have a ported head, Piper exhaust cam but retain VVC and a plenum for now. I may go solid cams and throttle bodies in the future but I dont want the aggro of pulling the bottom end apart again. I still have the 1.6ss engine in the car so its not like I'm taking the car off the road while I do this and I could store that one in case it fails when its done. Not that I think it will. Simon Link to comment Share on other sites More sharing options...
Steve Day Posted April 13, 2006 Share Posted April 13, 2006 Yes, I have to admit to being surprised that mine went bang. It was built by a chap who has a lot of experience with K series engines and has also built other engines for me (no probs). He didn't build Alex's engine, so it wasn't the builder (imo) probably a component failure. Thanks for the commiserations Alex! Not sure if I'll build another Cheers Steve Link to comment Share on other sites More sharing options...
Jason Plato Posted April 13, 2006 Share Posted April 13, 2006 upto a 9% improvement in torque and a little more power is seen from a 1800 > 1900 conversion with like for like mods. I think if you are doing a conversion and you have to buy pistons then it makes financial sense. But the Pistal pistons that come with the scholar kit are a very short skirt so its too early to say what their longetivity will be. Link to comment Share on other sites More sharing options...
simon_h Posted April 13, 2006 Author Share Posted April 13, 2006 Thats not a bad gain. As its mostly a road car then the torque would be good, the 1.6 is a little gutless down low, fine when you get going though. Probably wont notice the gain as much when its in VVC guise as I wont be going above 7200rpm. Its because I already have the Omegas that I am unsure. As you say if pistons are needed then its probably worth the risk. I doubt if the Pistal ones will wear out before 10k miles which would probably be ok. I saw them the other day and there isnt much to them I agree. All depends on how much I could get for the Omegas I guess. Link to comment Share on other sites More sharing options...
Rob Walker Posted April 13, 2006 Share Posted April 13, 2006 As a matter of interest what Piston and con rods were used in the two 1.9`s that failed? and were they drysumped? Rob Link to comment Share on other sites More sharing options...
silver-7 Posted April 13, 2006 Share Posted April 13, 2006 Rob, mine and Steves cars had different rods & diff cranks ! mine had Caterham dry sump - R500 set up Arrow steel rods, DK Steel crank, Scholar pistons, bottom end was built up by scholar. I was at Scholar yesterday to drop off a few parts, there still awaiting a batch of new liners, getting a bit Pissed as its taking ages !!!! all i want is a working car ! Pleased to hear there are plenty of guys out there with strong engines. On concideration could be the fact that i was reving to 8,300 rpm in hindsight that might not have been wise ! 😬 looking at the power curves im not going to rev past 8k next time. cheers Alex Link to comment Share on other sites More sharing options...
Petrolhead Posted April 13, 2006 Share Posted April 13, 2006 It should be able to rev to 8300 though NE7Club Web Site R5 no 65 😬 Link to comment Share on other sites More sharing options...
silver-7 Posted April 13, 2006 Share Posted April 13, 2006 yep.... but after you have one let go you err........ get cold feet !! 😬 😬 😬 Link to comment Share on other sites More sharing options...
Rob Walker Posted April 13, 2006 Share Posted April 13, 2006 Alex, Thanks for the reply. I wondered if you had used standard rods and no drysump. Well that blows that theory. Do you know if VP2 uprated big end shells were used in the original build? 8300 should be no probem with an all steel bottom end. My 1.8 has been held at these revs for hours. Are you trusting Scholar with the reconstruction? good luck Rob Link to comment Share on other sites More sharing options...
silver-7 Posted April 13, 2006 Share Posted April 13, 2006 Rob, yes VP2 big end bearing shells were used, Im getting Scholar to rebuild the short block on this occasion. As you say 8300 rpm with an all steel bottom end really should be ok guess i was just unlucky. cheers Alex Link to comment Share on other sites More sharing options...
Steve Day Posted April 15, 2006 Share Posted April 15, 2006 ...and it seems like I ran it with too little oil 🙆🏻 it was most likely this that caused the failure...stupid mistake...and expensive... ☹️ Link to comment Share on other sites More sharing options...
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