PRO250 1,506 Posted August 20, 2014 Why was jasons old engine rebalanced? Ive never rebalanced one. Even the boosted engine my my ghia i just weighed the pistons all off the rods made the new ones weigh the same as the old ones and handed it all to the machine shop Share this post Link to post Share on other sites
bear351c 10,271 Posted August 20, 2014 I'm confused, so the inlet manifold causes the brackets to flex at high revs, and the belt to fly off....... Share this post Link to post Share on other sites
PRO250 1,506 Posted August 20, 2014 In short no. But its a crossy there a diffrent beast. If any of this info was around with i built mine i would have not killed mine as much with my shitty cast balancer. breaks the flywheel comes off and fucks the crank (front and back) and then you have to build it all over again a super good steel balancer fixes 90% of these issues did on mineYou have to remember ford turned these things 4000rpm, Then people build them to turn well past 6000 then all these things add to the issues they have. Ive not herd the head thing before but i supose it make sense 1 bear351c reacted to this Share this post Link to post Share on other sites
wagoon 2,429 Posted August 20, 2014 Well I was wrong, the balancer has been externally balanced. Pro it was rebalanced due to changing from auto to manual trans. The whole assembly was done from balancer to clutch pressure plate. Share this post Link to post Share on other sites
ando76 4,354 Posted August 20, 2014 PRO 250 - Ryan fitted new pistons to Jason's old engine and yes a shift to manual from auto so that was one reason for the 're-balance'. Generally once they are balanced you don't have to have them re-balanced - just if you add new bits. Cam at Engine Engineering is a bit of a freak like me and we trust what we see so everything was checked. Number one rule of engine building - check, check and check again and then once you are done that check it again and assemble. A bit of overkill yes but this engine is no stocker. Bear - yeah 6 cylinders are very different animals and you are continually fighting uneven cylinder fill. in most 4 barrel and 2 barrel applications you have 2 cylinders that work real well and the other 4 fight for flow so therefore they end up fighting the other 2. Of course as PRO250 has pointed out this only occurs when you flog the shit out of them and make them rev well past their original design parameters - which is what the OP is hoping to do by the sounds. Have a look at the fastest nat asp x-flows in the country and they are all individual runner set ups - the exception being the big h Corty which is flying the four barrel flag pretty hard at the moment. When the cylinders are fighting each other it causes harmonics and - along with spark scatter from the dizzy and the poor old balancer can't cope. The harmonics are enough to rattle flywheel and flexplate bolts (torqued to 110nm) loose so it's not to hard to see what they would do to a flimsy alternator bracket as well as a poor old balancer. When you have even cylinder fill, no spark scatter (crank triggered ignition) and a good (ATI) balancer you have one very happy x-flow that will rev to 7000 and be happy doing it. 2 bear351c and gerg reacted to this Share this post Link to post Share on other sites
bear351c 10,271 Posted August 22, 2014 Got it. Thanks Guys. Share this post Link to post Share on other sites
gerg 10,871 Posted August 22, 2014 Nice explanation there ando Share this post Link to post Share on other sites
ando76 4,354 Posted August 22, 2014 Thanks Gerg. I have spent an unhealthy amount of time on the flow bench testing manifolds and cylinder heads for crossflows. Old Joe at Ipswich can retire on the money I spent at his bench. I'm back using Anthony's bench locally now as he has updated all his software and has added a swirl meter to his bench as well - and he only charges a carton of xxxx Gold stubbies per visit. 1 gerg reacted to this Share this post Link to post Share on other sites
PRO250 1,506 Posted August 22, 2014 Well I was wrong, the balancer has been externally balanced. Pro it was rebalanced due to changing from auto to manual trans. The whole assembly was done from balancer to clutch pressure plate. Gone back to manual hey? Let the kaboom begin 1 nos2 reacted to this Share this post Link to post Share on other sites
nos2 751 Posted August 22, 2014 Number one rule of engine building - check, check and check again and then once you are done that check it again and assemble. This is what's going on with mine maybe.. x50 Share this post Link to post Share on other sites
PRO250 1,506 Posted August 22, 2014 PRO 250 - Ryan fitted new pistons to Jason's old engine and yes a shift to manual from auto so that was one reason for the 're-balance'. Generally once they are balanced you don't have to have them re-balanced - just if you add new bits. Cam at Engine Engineering is a bit of a freak like me and we trust what we see so everything was checked. Number one rule of engine building - check, check and check again and then once you are done that check it again and assemble. A bit of overkill yes but this engine is no stocker. Bear - yeah 6 cylinders are very different animals and you are continually fighting uneven cylinder fill. in most 4 barrel and 2 barrel applications you have 2 cylinders that work real well and the other 4 fight for flow so therefore they end up fighting the other 2. Of course as PRO250 has pointed out this only occurs when you flog the shit out of them and make them rev well past their original design parameters - which is what the OP is hoping to do by the sounds. Have a look at the fastest nat asp x-flows in the country and they are all individual runner set ups - the exception being the big h Corty which is flying the four barrel flag pretty hard at the moment. When the cylinders are fighting each other it causes harmonics and - along with spark scatter from the dizzy and the poor old balancer can't cope. The harmonics are enough to rattle flywheel and flexplate bolts (torqued to 110nm) loose so it's not to hard to see what they would do to a flimsy alternator bracket as well as a poor old balancer. When you have even cylinder fill, no spark scatter (crank triggered ignition) and a good (ATI) balancer you have one very happy x-flow that will rev to 7000 and be happy doing it. I went to a individual runners a long time ago, got told i was a moron. Funny by a big time crossy builder that shall not be named,got banned for some reason to Flywheel coming off, that was a issue ive had a few of. Good balancer and a well balanced engine seems to have fixed my issues after 4 builds smashing the cranks front and back even lost a clutch and flywheel at 8000 once missed a gear and it left the car in a big way. If it had gone the other way id not be walking now If only all this info was around when i was playing with them full on. I remember a bloke that worked for rocket said once when i was telling him the issues i was having, he said "force feed it and stop reving it" 3 weeks later i went blown 2 Thom and XES reacted to this Share this post Link to post Share on other sites
ando76 4,354 Posted August 22, 2014 Low revs does equal low stress and apparently 'your not known unless your blown' bahahaha. 1 Thom reacted to this Share this post Link to post Share on other sites
Thom 6,651 Posted August 22, 2014 Injection is nice, but I'd rather be blown Share this post Link to post Share on other sites
