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| Deck Plates | Rating: 
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| Posted: 09-20-2006 08:53 am |
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1st Post |
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Sylva Member
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I want to buld a top deck plate for a 910 Engine and a lower cradle for the bottom of the bearing ladder. But can't find difinitive info. Can anyone tell me. How thick should the cradle plate be and what grade of steel, the info on this web site is 1 inch, but pictures I've seen don't look that thick. What grade of steel should it be. My thoughts are to use a medium carbon steel. For the deck plate again how thick should it be, this is obviously limited by how much you can machine of the top of the block. Or do I need tomachine the plate with a step at the edge. And again what steel. Is it OK to hold the plate in place with just the head bolts, or do you need to dowell it. How do you locate the linners, my thoughts are to tapper the linners and the deck plate so that the linners stand proud of the plate and are "pinched' into place by the head. Has any one ever used these, are they worth the effort. My engine is the latest S4 Block with the bearing ladder dowelled to the block. and cast iron liners made to fit the latter block. I can sourcing material, even exotic steel, and can get all the machining done. T his is my pet project for over the winter, I'd really appreciate any info or experience you may have. Thanks
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| Posted: 09-21-2006 09:13 pm |
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2nd Post |
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Judson Manning Member 
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Sylva, That's a pretty neat trick getting the earlier iron liners to fit the later block, especially since the iron liners are smaller than the holes! As I read your post I can't help but wonder exactly what mode of failure you have experienced or feel you need to guard against? The #1 problem I've experienced is the mains getting warped and cutting off oil supply to the rod bearings. Is your S4 'zeus' casting not rigid enough to eliminate this problem? What is your target HP output and rev range? Judson
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| Posted: 09-22-2006 01:50 am |
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3rd Post |
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Sylva Member
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Dear Judson Linners wee supplied by Gary Kemp to fit the block. Re failers, I run a Sylva Phoenix with an all up weight of 600kg wet, (you can see pictures on the web) car was built aound my Lotus Sunbeam, using all the running gea except the from uprights. The oiginal car was used in some of the European Events as a support car fo Heni Tovinan when he won the world rally chamionship. So it had some funny things, e.g work head, but not the dry sump, woks fuel pumps, all the add on bits were as the wok car so it cold be stipped, but the sealed bit wen't. Any way this all went into the Phoenix, then I moved to Kuala Lumpur, and we have a vey high speed race track (Sepang F1) with two 1 km streights. In the light body the head just pulls all sotrs of revs. and throught the gears will out eev the block, the 911 block let go with Oil starvation to the mains. So I sourced a new block, spec is Light Flywheel (two plate clutch), S4 block, fully dowelled, S4 cross dilled crank, CE Pistons, HTD timing gear, (manual tension), Cams from Garry, S300 Esprit Valves, long cam followers, Top hat cam shims, Special valve Springs, resticed oil to head, Oil returns opened up, oil pump clearence educed. and of couse balance oil cooler, electic water pump ttc, In other words the 'works'. Now as you know Lotus are owned by a Malaysian Company, and I meet several of the old gus from the days when the Espits aced in the US. The advised fo high revs that I use these plate. but unfotunatly it appears the dawings were left in the USA 10 yeas ago and thee are no copies in Nofolk. Living in Asia, I am able to get things made vey cheaply, to a high standad, people still have lathes and miling machins and will make one offs. I don't know if it is the same in the USA, but in Euope eveyone wants to make a 100 on a CNC. So basically I'm tying to souce the info, if it looks do-able, I'll look at it ove the closed winte season. I can see 9,000 pm vey easily on my engine, but basicaaly what I'm looking fo is reliabilty fo a full season rather than all out power, can rouvh 170 Mph on the streights so bhp is not an issue, (I know I can push less with my right foot for reliability, but I'm easily tempted). Hope this answers your question, thanks for the interst, I joined this club because this is the best site, I've seen on the engine, and I've bought things from Greg so I hope you don't mind some one who dosen't have a JH Kelvin
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| Posted: 09-22-2006 03:29 am |
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4th Post |
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Judson Manning Member
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All who are challenged by the 9xx series engine are welcome! Garry Kemp is THE man when it comes to developing high HP 9xx series Lotus engines. About 10 years ago Garry showed me a 907 dry-sump casting he had developed, and I've been sold on his wisdom ever since. If I understand correctly, oil starvation to the mains is the problem and you are running a wet-sump oiling system with all the usual modifications? One possible cause of your problems could be presurization of the crankcase, and pooling of oil in the head at those higher RPMs. Also, your oil pump could be cavitating at the higher revs. A dry-sump system may be the solution. For a strapping plate, consider milling off roughly 10mm from the lower bearing panel and replacing it with a one-piece steel section. A medium carbon Cold-Rolled-Steel should be sufficient or you could use 304 Stainless Steel. The key is to use a grade of steel that is fairly rigid but easy to machine. The lower panel itself would make a great template for your machinist. There is a firm here in the States that makes the 'top plates' or 'block protector plates'. Their process is to loosely fit the plate between the liners and block, then tig-weld it into place. The block is then 'decked' and the liners are honed. Whatever you decide to do, please let us know and post some pictures.
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| Posted: 09-22-2006 03:37 am |
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5th Post |
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Ron Earp Member 
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Judson is doing my second motor here in the US and knows well what he speaks. Maybe you should go with a dry sump system? If not that, are your running an oil accumulator (i.e. Accusump) on the wet sump system with oil baffles in the pan, and maybe a trap door setup? I can't imagine you'd have oil stravation problems with an oil accumulator and trap door setup, but I might be wrong. Ron
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| Posted: 09-22-2006 04:43 am |
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6th Post |
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Sylva Member
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Dear Judson and Ron I can't run a dry sump no room under the bonnet, my car is built around a space frame designed for a 1.3 Ford Kent Engine, mine was built by Sylva for the Lotus Engine as a one off, but there is no room for tank and pump, I'm looking at an acusump for a winter projec,t and light rods, but my wife tells me I've spent my budget for this year. That why I'm looking at the plates, I'll be making progress, using my time and not spending money. I've got all the Oil mods, and I don't think I get oil starvation with the S4 sump as it is heavly baffeled. I'm realy just looking/playing at mods, and improvments. (I did get oil starvation with the 911 block and sump). I've got OIl restriction to the head, and opened up the returns, oil pressure is now good all the time in all the turns. My crank case breathes to a oil catch tank, and the engine had JP ring and pistons on new bores, when last run, so crank case pressure should not be an issue. My last problem was that the HC JP (11.25) pistons touched the head gasket at 8500 and three pistons split. I'm now installing 10.5 CE pistons. This was caused by the guy who assembled the engine not putting the roll pins in the head and misaligning the gasket. (he is not working on my engine now). Hope to have the pistons in and the engine in today, ready for track day on Sunday. If I mill 10 mm of the of the bottom of the bearing panel, how do I attach to the bearing panel, (tap and thread, then bolt?), From memory, 10 mm would just about bring the bottom of the bearing panel level with the bottom of the main bearing end caps, so I pressume I would also extend the bolts on the main bearing and bolt there? How thick is the top deack plate? I thought you had to mill the top of the block down, and I was afraid of that as I do not think I can get a new S4 block again if I went to far, (changiing engine umbers is an issue here). but tig welding is easy. If the plate is tig welded how do you take the liners out, I pressume you can't without 'breaking the weld? I am looking at this, but it will be over the winter and I will keep you informed with pictures. Thanks Kelvin
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| Posted: 09-22-2006 02:07 pm |
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7th Post |
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Judson Manning Member
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I figured you had a good reason for not running the dry-sump. They are expensive and do take up a great deal of room. And yes, my wife has informed me my racing budget has been spent for the year as well! One strapping plate option is to sandwich a new plate between the lower bearing panel and the sump. This adds depth to the sump (which may be a good thing), but the further you get from the journels, the less impact such a plate will have. The increased distance from the journels is just one reason why I suggest 'making room' for the 10mm plate by milling the lower bearing panel. In the end, I think the S4 block has plenty of rigidity without such a plate. The top plate is actually an segmented insert that fits between the block and the liners. The idea is to transform the Lotus block into a solid chunk of aluminum thereby eliminating any flex at the top of the liners. As you've pointed out, removing the liners at some time in the future is now impossible. As long as your engine builder remembers those locating dowels, I don't think the top plate is necessary. If you are using over-bore pistons and/or pistons with an upper crown, a typical modification is to chamfer the top of the piston. This gives more piston-to-wall clearance where the piston comes in close contact to the head-gasket.
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| Posted: 09-25-2006 02:03 am |
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8th Post |
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Sylva Member
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Can't put the plate in the centre of the bearing line as my block has the +15 main bore, so re-line boaring would be difficult, as I could not source new bearings to fit (unles some one knows better?) Had alook the weekend at my pare block (911) and I think what we will do is build a spare engine around this with a top and bottom plate, before I 'experiment' on my S4 block. I'll make a post here when I get it sourted.
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