EFA Posted May 21, 2001 Share Posted May 21, 2001 On Saturday I put the engine back in my car and fired it up, and except a very slight soft knocking noise for about 30 secs when it first ran (despite priming the oil system) it ran fine right up to the point when I was going to take it off the trestles I use when doing these things and return to ground level. At this point I noticed an oil leak between the rear of the sump and the bellhousing. Oh yippe I cried, a bad rear crank seal...... So I thought I'd take off the sump and re-seal it with the GM gooey stuff and try it again. So off came the sump whne to my horror I saw the tips of the web adjacent to big end 1 were blued. Forgot all about the oil leak, when outside and kicked the wall of the house very hard, then came in a removed the bearing cap expecting to find a mess. Nothing. Bearing and journal were fine. Very weird. So tonight I have removed the engine from the car (with assistance from Richard Larkham ....again) and stripped the bottom end. A closer examination of the crank reveals no damage, all within dimensional tollerance, just the tips of the webs have gone blue. A quick rub with some scotchbrite and the blue stuff has come off. Now whether this is the dye they mark the bearings with to denote .25mm oversize (which in this case is also blue) or actual very slight heat marking is not known. All I know is that I hope the rear crank seal was the cause of the leak otherwise I have just removed and stripped my engine for nothing........ So Wednesday night I'm screwing the engine back together, and Saturday we'll be throwing it back in the car. The only question I have is with the lead indium bearings. They all have worn some thin lines through the dull surface to the shiny lead underneath. The bearings feel very smooth still and you cannot feel the lines on the surface at all. Is this the norm for an engine which had run for about 10 minutes??? If this were an engine that had done 1000 miles there would be no case for swapping out the bearings, but as its run for such a short period of time I'm wondering if I need to lube them with more than Mobil 1 before I crank it to get the pressure up. I guess the other method is to remove the oil pump belt and spin the pump up to pressure on an air ratchet......... All ideas welcome. Thx Arnie Webb The Fat Bloke blush.gif in a Fast Temporarily Indisposed Vauxhall wink.gif See the R500 eater here See the Le Mans Trip Website here Link to comment Share on other sites More sharing options...
R2D2 Posted May 22, 2001 Share Posted May 22, 2001 If the "tips" have blued because of heat I think you have a BIG problem. The temper colours developed when you heat steel give a fair indication of temperature and in fact the old Engineering handbooks used colour decription to define tempering temperatures. From memory a "blue" temper would be about 450 degC and I can't really believe that the crank has become this hot without totally trashing the shells. The problem is that you would be able to clean the thin oxide film that causes blueing with scotchbrite so there isn't much evidence left. I would always tend to build an engine with Graphogen to get a small amount of boundary lubrication before the engine fires up but I know some people disagree. Did you check the bearing clearances with Plasti-gauge before you finally assembled the engine? Now you have it stripped again I think it would be worth the troubel just for peace of mind especially if you are worried about a bearing running hot. Link to comment Share on other sites More sharing options...
EFA Posted May 22, 2001 Author Share Posted May 22, 2001 Chris, The blue appears to be ink from the bearing size indication! I checked the clearences and all is OK. Do you know where I can buy Graphogen??? Arnie Webb The Fat Bloke blush.gif in a Fast Temporarily Indisposed Vauxhall wink.gif See the R500 eater here See the Le Mans Trip Website here Link to comment Share on other sites More sharing options...
R2D2 Posted May 22, 2001 Share Posted May 22, 2001 Arnie, To say that nitriding is 20 thou thick is a bit misleading but this is a figure quoted by a great many commercial heat treaters. As nitriding is a diffusion process which relies on the formation of nitrides there is a "hardness gradient" from the surface into the body of the component. A "T" Condition EN40B crank would have a core hardness of 300 Hv. The nitrided surface would be about 1000/900Hv depending on the detailed heat treatment that had bee carried out. At a depth of 20 thou (0.5mm) I would be surprised to see the hardness higher than 350 to 400 Hv so most of the wear resistance will have been lost. At 5 thou depth the residual hardness will probably be 700/800 Hv which isn't too bad Link to comment Share on other sites More sharing options...
Chelspeed Posted May 22, 2001 Share Posted May 22, 2001 Demon Tweeks sell an engine assembly lube made by red line oils. It's called red line engine assembly lube.... page 204 in the catalogue. It's a red paste in a tub, you put a finger full on each bearing before assembling and it would stay there for weeks if you stored the engine before running it. Works well. Link to comment Share on other sites More sharing options...
R2D2 Posted May 22, 2001 Share Posted May 22, 2001 I think Burton's sell Graphogen. Sorry about the mixed up post about nitriding. I didn't mean to post it here, just brain fade! Link to comment Share on other sites More sharing options...
Paul D Jones Posted May 22, 2001 Share Posted May 22, 2001 I was told no to use Mobil one in a new or rebuilt engine until it had done a few hundred to a thousand miles as you should change it then and its very thin and could have caused the slight damage you discribed to see if its heat blue or dye heat up an old rod with a blow torch let it cool then see if it comes of as easy as the suspect the one Paul Link to comment Share on other sites More sharing options...
Swiss_Tony Posted May 22, 2001 Share Posted May 22, 2001 The reason for not using Mobil 1 or any other synthetic oil in a new engine is that it cannot bed the bearings and rings in. A decent non synthetic oil is much better then change it when it is run in. James Link to comment Share on other sites More sharing options...
EFA Posted May 22, 2001 Author Share Posted May 22, 2001 Interestingly Swindon run in on Mobil 1 15/50. I would suggest nobody has spent more on R&D of tuned VX engines than Swindon. They also say run it for 10 mins and then you can thrash the pants off it - so sure they are of their (and Arrow and DKE's manufacturing tolerences. They actually said its a bad idea to run in using mineral oils as you cannot clear them from the system without purging with Mobil 1 several times. Matthew (AVES) bought over some Graphogen tonight so I will use this during the reassembly. I might try blueing an old rod to see how it cleans up, but I am now very very sure this was foreign material rather than heat damage, as the heat source would have to leave witness marks on a bearing or thrust surface. We'll see if its OK Saturday. Thx for your advice guys. Arnie Webb The Fat Bloke blush.gif in a Fast Temporarily Indisposed Vauxhall wink.gif See the R500 eater here See the Le Mans Trip Website here Link to comment Share on other sites More sharing options...
Swiss_Tony Posted May 22, 2001 Share Posted May 22, 2001 Arnie They probably use Brasso to run the rings in! James Link to comment Share on other sites More sharing options...
CHRIS CLARK Posted May 23, 2001 Share Posted May 23, 2001 The cynic in me says "Do 'they' really want your engine to have good performance & last 'forever' or would 'they' be better with your engine having fantastic performance for a fairly short time?" What keeps who in business? UUUUUmmmmm. Same apply to Minister et al ? Not you though Mr King sir!!!!! Link to comment Share on other sites More sharing options...
I.Mupferit Posted May 23, 2001 Share Posted May 23, 2001 Chris Sounds like you have been in Industry in this country for far too long! Thought it was only me who was such a cynic. thumbsup.gif Brent Link to comment Share on other sites More sharing options...
Peter Carmichael Posted May 23, 2001 Share Posted May 23, 2001 Pretty much all of running in is to do with the microscopic bedding of the piston rings to the bore walls. The varying need depends on the bore finish and the piston ring material. Roger King will tell you that certain plateau honed finishes can stand up to immediate full throttle and revs use, but you need to know what processes were used on the bores to achieve the finish otherwise you will irreparably compromise the piston ring sealing. Link to comment Share on other sites More sharing options...
oilyhands Posted May 23, 2001 Share Posted May 23, 2001 Flex-hone honers with Carbide balls give a very fast, fine bedding in surface to bores, coupled with moly rings you will have a much faster route to running in. I always use a mixture of 50% Wynns/STP and 50% Mobil 1 as an engine assembly lubricant, it has more staying power than oil alone. Oily Link to comment Share on other sites More sharing options...
Roger King Posted May 23, 2001 Share Posted May 23, 2001 Peter, I wouldn't quite go so far as to state that a plateau finish will take full throttle use immediately, but you certainly don't see cars with 'running in, please pass' stickers any more (showing my age here). I was once lent a technical manual for engine reconditioners from the immediate post (WW2) war period. I quote "there is a growing body of opinion - which this writer does not share - that honing the cylinder after boring can be beneficial"!!!! Not written by Keith Duckworth then? Flexhones can be an excellent way to achieve a plateau finish, but they won't recover a bore finish that is fundamentally unsatisfactory. I proved this to my cost on more than one occasion; which must mean I'm not bright enough to learn quickly from my mistakes. Brasso comments may be nearer the truth than you think. 20 years ago I worked with someone who had been apprenticed to BRM and I don't think he was winding me up when he said that they lapped valves in with progessively finer paste, finishing with Brasso. Edited by - roger king on 24 May 2001 00:22:16 Link to comment Share on other sites More sharing options...
CHRIS CLARK Posted May 24, 2001 Share Posted May 24, 2001 Roger. This technical manual. Was it lent to you just after the conflict when you first started in business?...........!!! It's just that everyone says you have a lifetime of experience. Does that get me off the hook ? Probably not!!! Link to comment Share on other sites More sharing options...
Roger King Posted May 24, 2001 Share Posted May 24, 2001 Chris, You go straight to the top of my death list where you join Mike Bees. Yes, it is true that I have a lifetime of experience - I just don't know whose lifetime, or what they experienced. Edited by - roger king on 25 May 2001 00:04:35 Link to comment Share on other sites More sharing options...
CHRIS CLARK Posted May 25, 2001 Share Posted May 25, 2001 The TRUTH is out there..................somewhere ! Link to comment Share on other sites More sharing options...
Mike Bees Posted May 25, 2001 Share Posted May 25, 2001 Ok Chris, let's run in opposite directions - that halves our individual chances of getting caught. Mike Link to comment Share on other sites More sharing options...
R2D2 Posted May 25, 2001 Share Posted May 25, 2001 Has any one tried this cylinder finishing technique? http://www.poetonaptec.co.uk/liners.htm I think that this system is used on a couple of F1 engines with good results and it seems a good idea on a high revving engine. I have used liners honed by Perfect Bore on an Imp engine that revs to 10000rpm with good results but never tried the Apicote finish. Seems like a good idea for a high revvin K series. Link to comment Share on other sites More sharing options...
Simos Posted May 25, 2001 Share Posted May 25, 2001 Roger, I always thought that the engine building community would be populated with such calm controlled folk - methodical, measured, deliberate.... Now I find it's a hotbed of intrigue, death threats and violence that would makes a Tom Clancy novel look like Jackanory ! Presumably all the horsepower in my engine is from this hot-bloodedness rubbing off as you hone the bore..? Simon. Link to comment Share on other sites More sharing options...
Roger King Posted June 1, 2001 Share Posted June 1, 2001 Yup! Link to comment Share on other sites More sharing options...
AMMO Posted June 1, 2001 Share Posted June 1, 2001 Chris I've used Aptec (and several other Nikasil type finishes) on several occasions. The old Moto Guzzis I work with have had plated ali bores since the late seventies. It ain't rocket science. Originally it was probably done to cut the work it takes to install liners in air cooled engines. Funnily enough the other manufacturer that also used this process on an air-cooled engine was Mahle for the Porsche engines. It is lighter than cast iron, but I doubt very much it makes any more horsepower. In fact when talking to Geoff Roper who used to be the head of the piston department at Cosworth in the early eighties he said to me they had run V8 engines in both Nikasil and cast iron bore and could not measure any difference in power. By the way, Perfect bore (who I've also used) make liners and hone them on Sunnen machines. Aptec do the plating for Pefect Bore and Perfect Bore hone for Aptec. You'll get a pretty good job from either of these firms although I've had my differences with both of them. Regarding revability (is that a proper word?). This has got a lot to do with engine stroke. I'm amazed how high some of these very strokey K series engines rev. I recently got to inside one for the first time. Very nice and dinky but could do with being oversquare, with bigger valves and some other way of sorting the liners out. The engine I saw was definately sloppy in the liner to block department. Maybe a custom block with Nikasil plated bores based around the 1600 crank would be fun. But then that would be a completely different engine. AMMO Link to comment Share on other sites More sharing options...
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