R Cubed Posted March 16, 2012 Author Share Posted March 16, 2012 Hi R,Not a problem, I am glad you have answered my post that way. As for the possibility of the exhaust blow being mistaken for a knock, without going back to the beginning, I seem to think there could have been questions regarding ignition timing, if it had been a touch retarded, that will give you a very harsh exhaust note so could be interpreted as a knock. One thing I was not sure about was when you found the rings were worn so badly, did you use a Mercer guage to check the bore wear? Could not remember reading about it, as with very worn rings, I would expect bore had suffered as well. regards, Richard I did check the bore wear but only by using the new rings :blush: There was no scoring or gouge lines in the cylinder bores but were very shiny I think I have posted about the new and old rings but just to go over it again the old rings which came off the pistons in their respective cylinders all had excessive ring end gap over 40 thou with the new rings in the cylinders after a hone they were just about 4 thou if I can remember rightly so I believe the wear was in the rings rather than the cylinders. Quote Link to comment Share on other sites More sharing options...
deadline Posted March 17, 2012 Share Posted March 17, 2012 Did you plasti-gauge the rod bearings? Re-check the motor with a vacuum gauge.. if you had two leaking valves AND super worn rings that would have shown up as low vacuum or a bouncing needle. If you check again the vacuum gauge should be at a SOLID 20 in Hg (or whatever it is in mm/Hg). My jeep motor had a very consistant 3in Hg bounce.. new rings, valves, lapped valves and new springs I get a SOLID 20in/Hg. Its like a new motor. Quote Link to comment Share on other sites More sharing options...
R Cubed Posted March 19, 2012 Author Share Posted March 19, 2012 Yes did use Plasti-gauge all big ends were the same and no scoring. Have not checked the vac as yet due to still sorting out the inlet and exhaust manifolds. Quote Link to comment Share on other sites More sharing options...
MICHAEL01 Posted March 19, 2012 Share Posted March 19, 2012 Hi All Just out of interest, recently rebuilt my diamond t engine(engine shells that are pictured in earlier thread l can show equally as good) Does the Jimmy crank require shims to set the right clearence on shell clearences to crank faces. Also to take up end play on the jimmy does it use 2 sets of half semi circle phosphorus bronze shells on the back end of the crank? Cheers Michael. Quote Link to comment Share on other sites More sharing options...
deadline Posted March 20, 2012 Share Posted March 20, 2012 No shims on any bearing cap. I'd have to look in the TM about the crank thrust bearing... but the SNL does not mention shims.. just a spacer. And they are not called Jimmies. I know that will ruffle some feathers.. but gotta break people of the habit. Quote Link to comment Share on other sites More sharing options...
Degsy Posted March 20, 2012 Share Posted March 20, 2012 No shims on any bearing cap. I'd have to look in the TM about the crank thrust bearing... but the SNL does not mention shims.. just a spacer. And they are not called Jimmies. I know that will ruffle some feathers.. but gotta break people of the habit. We know it is incorrect to call them 'jimmies' in a historical context and it tends to apply to post war vehicles in the US but it is commonly used here probably because we don't have post war GMC's here. Quote Link to comment Share on other sites More sharing options...
deadline Posted March 20, 2012 Share Posted March 20, 2012 Ok.. I guess I won't change the minds of an entire contentment. Was worth a try. As for the knocking if the bearings were in spec (.002-.0035 or so) then I'd really reevaluate the whole 'knocking' diagnosis A quick google of 'engine knock' will quickly convince you that 'engine knock' is such an mis-diagnosed symptom that the term is effectively useless. My 'engine knock' for my jeep was valve guides. Now the tappet adjusting screws are ticking due to wear. Quote Link to comment Share on other sites More sharing options...
R Cubed Posted April 15, 2012 Author Share Posted April 15, 2012 (edited) A good up date to this sorry situation. Well I have tracked down the knocking noise to what was a blowing exhaust manifold gasket joint at the cylinder head on number 3 exhaust port, the manifold was in a bad way, rust and corrosion round the port faces meant they did not seal tight enough and a crack after port 3 towards port 4 ( at the rear of the engine ) I don't want to pay for a new cast manifold at the moment sooooo........ I have manufactured my own tubular manifold and this has solved the problem. Edited April 16, 2012 by R Cubed Quote Link to comment Share on other sites More sharing options...
Degsy Posted April 15, 2012 Share Posted April 15, 2012 Well done Richard, that could just be the start of a business venture.:thumbsup: Quote Link to comment Share on other sites More sharing options...
R Cubed Posted April 15, 2012 Author Share Posted April 15, 2012 (edited) Just before anyone mentions it, yes the middle two exhaust tubes are bigger than the end two as the end two are single ports and the middle two are shared ports. I suppose I could make some, would need to make a jig to set the cylinder head flanges and down pipe flange in the correct places first though Oh there is more to this pic than meets the eye the best bit is just off the top of the pic but more of that latter.. Edited April 15, 2012 by R Cubed Quote Link to comment Share on other sites More sharing options...
Richard Farrant Posted April 15, 2012 Share Posted April 15, 2012 Oh there is more to this pic than meets the eye the best bit is just off the top of the pic but more of that latter.. So have you gone for an LPG conversion then? Quote Link to comment Share on other sites More sharing options...
Vulture Posted April 16, 2012 Share Posted April 16, 2012 A good up date to this sorry situation. Well I have tracked down the knocking noise to as i eventually have worked out was a blowing exhaust manifold gasket joint at the cylinder head on number 3 exhaust port, the manifold is in a bad way and don't want to pay for a new cast manifold at the moment sooooo........ [ATTACH=CONFIG]60409[/ATTACH] I have manufactured my own tubular manifold and this has solved the problem. Like what you've done there Well done Quote Link to comment Share on other sites More sharing options...
R Cubed Posted April 16, 2012 Author Share Posted April 16, 2012 So have you gone for an LPG conversion then? Nope !!!!!!!!!!!!!!!!!!!!!!! Quote Link to comment Share on other sites More sharing options...
N.O.S. Posted April 16, 2012 Share Posted April 16, 2012 Does it involve creating a large 'Power Bump' and inlet grille in the bonnet? :shocked: Quote Link to comment Share on other sites More sharing options...
R Cubed Posted April 16, 2012 Author Share Posted April 16, 2012 Does it involve creating a large 'Power Bump' and inlet grille in the bonnet? :shocked: No it all fits in under the bonnet :blush: Quote Link to comment Share on other sites More sharing options...
N.O.S. Posted April 16, 2012 Share Posted April 16, 2012 This is better than a Clive's Mystery Object :-D Quote Link to comment Share on other sites More sharing options...
R Cubed Posted April 16, 2012 Author Share Posted April 16, 2012 NOS you know me too well or do you have control of a satellite round my way :shocked: Anyway here is a bit more of a pic mmmmmm what could it be..... Quote Link to comment Share on other sites More sharing options...
N.O.S. Posted April 16, 2012 Share Posted April 16, 2012 Twin S.U. carbs? Won't there be a lot of frost on that inlet though? Quote Link to comment Share on other sites More sharing options...
R Cubed Posted April 16, 2012 Author Share Posted April 16, 2012 Twin S.U. carbs? Won't there be a lot of frost on that inlet though? Nope, not twin S.U.'s but you are getting warmer.... Frost might be a problem but time will tell ! Quote Link to comment Share on other sites More sharing options...
Richard Farrant Posted April 16, 2012 Share Posted April 16, 2012 Nope, not twin S.U.'s but you are getting warmer.... Frost might be a problem but time will tell ! Twin choke Weber :cool2: Quote Link to comment Share on other sites More sharing options...
R Cubed Posted April 16, 2012 Author Share Posted April 16, 2012 Ok ok I think I have teased you all enough so here you go.. Please note no vac line to hydrovac, throtle linkage or rocker cover breather connected yet. mmmmm Weber 4 barrel with vac secondaries.... No it's not leaning over it is the angle of the camera, although the inlet manifold is not level ( front to back ) and the carb is. Front view looking towards cab. mmmm square carb mounting plate to round tube to fit the manifold tube assy now that's a challenge :nut: Looking down from the side. We will have to see how it does or doesn't perform :cry: Quote Link to comment Share on other sites More sharing options...
ian201 Posted April 16, 2012 Share Posted April 16, 2012 Richard, looks like a good job , Need to see what the truck will do around Goodwood in September lol. Ian Quote Link to comment Share on other sites More sharing options...
Degsy Posted April 16, 2012 Share Posted April 16, 2012 :wow:I think a rev limiter might come in useful;) Quote Link to comment Share on other sites More sharing options...
Vulture Posted April 17, 2012 Share Posted April 17, 2012 Ok ok I think I have teased you all enough so here you go.. Please note no vac line to hydrovac, throtle linkage or rocker cover breather connected yet. mmmmm Weber 4 barrel with vac secondaries.... No it's not leaning over it is the angle of the camera, although the inlet manifold is not level ( front to back ) and the carb is. Front view looking towards cab. mmmm square carb mounting plate to round tube to fit the manifold tube assy now that's a challenge :nut: [ATTACH=CONFIG]60442[/ATTACH] Looking down from the side. We will have to see how it does or doesn't perform :cry: Awesome !! :dancinggirls: The purists will be offended, but I'm fascinated to hear how it performs ! Quote Link to comment Share on other sites More sharing options...
rosie Posted April 17, 2012 Share Posted April 17, 2012 Awesome !! :dancinggirls: The purists will be offended, but I'm fascinated to hear how it performs ! From the very first attempt, she sounds sweet! Quote Link to comment Share on other sites More sharing options...
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