| Author | Message | ||
     Jeff Martin Frequent User Username: jeff_r_1 Post Number: 643 Registered: 07-2018 |
I'm having a bugger if a time trying to find someone here in Canada to clean up my tappets to a flat surface. Yes they are flat, or at least they're meant to be, I have a new old stock one meant for a Cloud 1 or S1, and it is flat; there is no crown on it. Jason Watson has a set of new lifters for his S1 from new old stock and they are all flat _ he checked for me. All the intake lifters all have the same part numbers across the board for all the in-ling 6 engines. The exhaust lifters are the same dimensionally except that they are threaded 5/16 UNF at 24 tpi for the Cloud 1's and Bentley S1. Anyone here know of anyone that can grind them flat again, one is worn like a tube cake pan, or like a castle moat with a high tip in the middle and high edges from the 50 degree lobed cam. It's worn bad enough that I can feel the wear with my finger and even see it in the light. I think one problem is that they're simply too big to fit into anyone's grinding machine, but I'm not sure about that.    | ||
| Jason Watson Experienced User Username: crikeydawn Post Number: 167 Registered: 07-2023 |
Jeff, thought it was just Australia loosing skills. However I know of a little engineering shop here in Brisbane Australia that does some fine work. I'll send you a PM | ||
| Bill Vatter Experienced User Username: bill_vatter Post Number: 168 Registered: 09-2004 |
This should be a simple task for any machine shop. You need a lathe with a tool-post grinder, which are pretty basic machine tools. Incidentally, the full-width cam is the early design. Later camshafts have the angle cut-off, which was intended to increase tappet rotation. I have no idea if that works amy better than the full-width cam lobe. Grind the tappets flat, and you should be good. if interested, I have a bunch of used tappets, nice and flat on the bottoms. | ||
| Jeff Martin Frequent User Username: jeff_r_1 Post Number: 646 Registered: 07-2018 |
Thanks Bill, I may take you up on those lifters, I'll send you a PM if that happens. The problem is that no one seems to want to bother with me, everyone is just so busy with North American stuff. I've even told the machine shops that new lifters are £78.00 each, so have at her, you have lots of money to play with to cover your time. I've even contacted a couple of places in the UK and the one in Australia that Jason suggested, and I just get ignored. I'm dealing with Egge Machine shop now, but I'm not holding my breath. Not that it matters now, but if the full width cam is an early design, why did they appear in the SC1/S1 parts book later on, none of the part numbers for the 50 degree cut-off cams appear anywhere where the last days of the in-line 6 is concerned. (I can't check right now, the technical library is down again) | ||
| NormanGeeson Unregistered guest Posted From: 81.98.117.162 |
Jeff If the faces are almost free of pitting, I would avoid regrinding the tappet faces at almost any cost. The reason is that you are in danger of exposing some pitting…. you will already have a set of good fitting tappets and you could lose some. If that were to happen finding replacements might be tricky. If you have tappets that are free of pitting you are a very lucky man, only replace them if necessary. Hand polish them if you are concerned. You are probably afraid of polishing off square, probably you are not aware but early S1 camshafts (UE698) had 0.5 degree taper across each cam, they are certainly off square. When you have considered all the points, I doubt you will be far away from the effect of the UE698 camshaft as your cam lobes are likely to be worn longitudinally. Check your camshaft bearings thoroughly and beware that YOU CANNOT see the worn section of these bushes without the aid of a mirror as the worn sections are on the blind side. When the camshaft is removed, trim the edges of the camshaft bearings 360 degrees around each bearing lip, front and rear. Failure to do so is an invitation for a worn bearing lip to be sheered off when it can drop straight into one of three main CRANKSHAFT bearings, No2 main is the favourite. Don’t reverse the camshaft thrust washer!! If you are checking these tappets for correct fitting, I suggest the following. Clean each tappet and its bore. Fit each tappet in its bore, in dry condition. The tappet should only drop down the bore very, very slowly. Then repeat the exercise after lubricating the tappets and bore with WD40. In this case the tappet should go down the bore smoothly needing only the weight of a finger at most. Make sure No 5 inlet has more clearance such that the tappet should proceed down the bore in the dry state quite quickly. (Message approved by david_gore) | ||
| Jeff Martin Frequent User Username: jeff_r_1 Post Number: 654 Registered: 07-2018 |
Norman My S1 cam is part# UE3736 and was ground by a machine shop in the UK for Flying Spares. I tried to find out exactly how that cam was re-ground, without success. I had my machinist of more then 30 years measure for "taper" on the lobes and there was pretty much none, "see photo".  I put a few of the lifters in place with the valves (2 of the exhaust valves were installed in the block for testing) and I was getting rotation with the NOS lifter on the right, but none with the worn lifter in the photo.  UE3736 doesn't show up here in "cam details", but the way it measures up, I'm going to assume that it is "offset", but in the end, they all appear to be offset in the block, or at least the cams that I have had in my hands were/are. (literally) http://au.rrforums.net/forum/messages/16999/CAM_DETAILS-44753.pdf While I'm sure there were others, only one cam is listed in the S1/Cloud1 parts book, and that is UE3736, I could find anything in the service bulletin about any others cams either. | ||
| David Gore Moderator Username: david_gore Post Number: 4271 Registered: 04-2003 |
Christopher Carnley has asked me to post the following information on his behalf: "This camshaft was removed from a 1953 R Type engine only slightly worn at Nos 5&6. All of the MK VI / R Type camshafts had the 50 degree cut off. The camshaft was replaced by an unused original S1 shaft."  . | ||
| ChristopherCarnley Unregistered guest Posted From: 3.8.158.41 |
Only a few of the camshafts in 1955, Part U689 had the tiny taper. None of the U3736. The tappet (lifter) on the left is early MK VI. The cast iron tappet faces were cast to "chills" that make them extremely hard. HB900. Having so much carbon in solid solution makes them very reactive to mild acid, ie dirty water, resulting in the bad pitting. Industrial wet grinding is required to take out the pitting. (Message approved by david_gore) | ||
| Jeff Martin Frequent User Username: jeff_r_1 Post Number: 655 Registered: 07-2018 |
Norman, At the time of your post, a friend of mine (a retired air craft mechanic of many decades) had already finished with them. As Chris said, "industrial wet grinding is required", and that's what was done. It was a large machine with a magnetic clamp table where each lifter was clamped in a V-Block _ done one at a time _ took Tom 4 hours. It actually wasn't Tom's machine, but a retired machinist who kept his own equipment. All went well as you can see from the photo. If I had known that this was going to be such a chore to get the lifters (tappets) cleaned up, I would have done this months ago. I never did find out how Egge machine shop in California was going to tackle this. What was also surprising was the lack of knowledge about this design concerning the tappets and camshaft, not even Flying Spares seemed genuinely interested in finding out. They wouldn't even put me in contact with their machine shop, I don't know what the deal with that was. It's such a pity that the old method's are being forgotten, or so it would seem. Below is from #2  . | ||
| Jeff Martin Frequent User Username: jeff_r_1 Post Number: 661 Registered: 07-2018 |
I installed UE3736 today, and I only get good rotation on No.1 exhaust, that's with its valve installed and correct clearance; I have the cam/tappet lubricated with moly grease. There's no rotation on any of the exhaust valves except No.1. Just out of curiosity I installed the cam in the 4.5 litre block I have, and I get the same results. Is it expected that the camshaft will break in where the tappets will start to rotate ? Maybe a proper break-in cam grease ? Exhaust tappet rotation on No.1 is achieved with the NOS lifter or the re-ground one that is from the engine originally. (that's the 4.25 engine) I'm thinking the cam is not ground correctly ? | ||
| Jason Watson Experienced User Username: crikeydawn Post Number: 184 Registered: 07-2023 |
Jeff, I have just bought myself a new electric verier. If you like, and think it will do the job, I'm happy to measure what you like. Send a pic of what you want measured. Alternatively I can take it to a shop who has the right gear. Think I have caught up, not hard leave me behind I can tell you. So these lifters rotate in their slot to address wear, lubrication, and so on. Early cams with ground lobes created moats in lifters from doing do. Your trying to address this with an S cam from a 4.9 which has full lobes, but they may, or may not have the slightest bevel on the lobe to encourage lifter rotation? | ||
| Jeff Martin Frequent User Username: jeff_r_1 Post Number: 662 Registered: 07-2018 |
All lifters rotate in their bore, not just for RR, but not roller lifters of course, the rotation is so even wear occurs across the lifter surface. There are exceptions to lifter rotation when it comes to bucket lifters and over-head cams, but that concept doesn't apply here. Early cams did create this "moat" wear in the lifter, but that is normal. I'm putting a cam from a 4.9 in because it breathes better, this is from Flying Spares "The inlet profile is improved from the original factory profile" and "The exhaust profile matches the original factory profile". Even though Flying Spares has matched the original exhaust profile on the 4.9 cam (UE3736), it's still an improvement over the original 50 degree cut-off cams. When comparing these cams, you can clearly see with your naked eye that UE3736 has much more lift on the exhaust lobes, this improves scavenging and thus better exhaust flow in an already poorly designed engine with the exhaust valves in the block. #1 Exhaust below is rotating successfully, you can clearly see almost full contact on the lobe, this what's supposed to happen.   #3 lifter is only grabbing half the lobe _ no rotation.  Even worse on 4 and 6   My friend that ground my tappets said "things will wear in", and perhaps he's correct as what you see here is just from me turning the cam by hand with Moly grease on the lobes and tappets. Using a thicker break in grease may help with this. I'm going to show the cam to my machinist and see what he says, it could be that not enough care was taken to get the top of the lobes parallel. Looks like the stone on the cam grinding machine needed dressing. |
