| Author | Message | ||
     James (Jim) Lee Yet to post message Username: graycar Post Number: 1 Registered: 8-2005 |
Hi everybody, I have removed and stripped the engine of my 1951 MK VI Bentley and, having read Norm Geeson's excellent article on cylinder blocks, Iwonder if anyone can recommend a good place to have the block and crankshaft machining done, where they understand the problems associated with these engines. Also, the cylinder head needs specialist welding. I will need to purchase liners, bearings, valve guides and springs, and clutch parts. Any suggestions on where to obtain parts would also be very much appreciated. I am based in the centre of Sydney metropolitan area. Thanks. | ||
| Marty Unregistered guest Posted From: c220-239-251-23.carlnfd3.nsw.optusnet.com.au |
Hi James, A few contacts for you: Repair & Restoration Services, Garth Selig. 0411 496 660. He is away overseas at present, but will be back in July I think. Based in Wetherill Park. John Vawser - Alexandria, 9698 8822 Machine shops - Peak Rebores, Mortdale, Col Sutton. 9579 4325 Col is a good guy, he is the owner and machinist. As for parts, Garth and John should be able to point you in the right direction. If you need any help, I am also in the centre of Sydney, at Rydalmere. Cheers Marty (Message approved by david_gore) | ||
| James (Jim) Lee New User Username: graycar Post Number: 2 Registered: 8-2005 |
Hi Marty, Thanks for your promt reply, I would appreciate the oppotunity to discuss the car with you. If that's ok please advise to my email address jayjaylee@optusnet.com.au . I am just on the West Ryde side of Marsden Road so we are almost neighbours. Cheers Jim. | ||
| Bill Vatter Frequent User Username: bill_vatter Post Number: 42 Registered: 9-2004 |
Jim, The following comments pertain to your cylinder block. The block is not magic. Any good machine shop able to do line boring can help you. Before starting work on the block, magna-flux test it all over looking for cracks. It does not make sense to spend money on a block that is cracked before you start. Look very carefully at the right side of the block all over the flat wall of the water jacket, particular attention to the bottom just above the oil gallery. Also look carefully at the deck in the area between the exhaust valve seats and the cylinder bores. Cracks sometimes start at the exhaust valve seats. Next you will need to get the rust and scale deposits out of the water jacket. That is usually no small job, working through the cover plates and holes. It is helpful to remove the screw plugs behind the pushrods in the tappet chambers for cleaning access. If you take those out, you should use new aluminum washers to prevent water-to-oil leaks later. Make sure ALL of the water passages are clear. Examine the camshaft bearings carefully before taking your block to the machine shop. The camshaft should spin very freely, the bearings should not be loose, and the surfaces should not show any degradation. If they pass this test they can be reused, but ONLY if the block is not cleaned with hot caustic. Solvent cleaning only or you must replace the camshaft bearings. Hot caustic will ruin the bearings. If you replace the camshaft bearings, then the new bearings must be line bored to the correct size 2.0000 inches after pressing the bearings into place. Caution with the camshaft bearings is needed to preclude failure after reassembly of the engine, which can be very expensive taking out not only the camshaft bearings but the camshaft and the main bearings and crankshaft main journals as well. The safe route, which Norman will declare the only route is new camshaft bearings, but I do not believe that is necessarily required, IF IF IF the block does not experience the hot tank at the machine shop for cleaning. Ask the shop to bore out the Brichrome liners and fit cast iron repair sleeves. No need to get expensive RR parts there. It is worthwhile and not expensive to fit steel exhaust valve seats, not for the non-existent lead problem, but as a preventative to cracking mentioned above. If you have a crack that is just beginning, you may be able to completely cut it out installing a steel seat. . Your exhaust valve guides are no doubt shot. Removing the guides is very difficult and the force required to press or drive them out of the block can crack the block. Norman recommends K-Line pressed in guide inserts, and I have found a screw in insert that is fit rather like a helicoil excepting the inside is straight rather than threaded. Then you ream the guide to fit. That will provide very good service for much less money than new guides, and you don't take the chance of cracking the block around the guide. It is worthwhile to have the machine shop cut the very smallest amount possible to make the deck flat. They will probably need/want to do this to cut the repair sleeves flush anyway. However it is important to take only the very smallest amount to prevent creating a clearance problem with the pistons and the cylinder head. When you get the block back, clean all of the oil passages yourself with brushes rifle barrel cleaners etc to ensure ALL of the sludge is removed. The sludge will convert to hard brittle and fragile carbon deposits, which could break loose later and plug something critical. | ||
| Stephe Boddice Frequent User Username: stephe_boddice Post Number: 52 Registered: 2-2005 |
Jim, It will be worth your while to spend a few hours reading through Ashley James' site: - www.kda132.com SB www.boddice.co.uk | ||
| James (Jim) Lee New User Username: graycar Post Number: 3 Registered: 8-2005 |
Bill and Stephe, Thanks for your replies. Stephe, I agree with you about KDA132 and am a regular reader. It was in fact this site that alerted me to possible problems with machining. Bill, many thanks for your tips and advice,Ihad not thought about the dangers of caustic cleaning re the camshaft bearings. Due to a lot of unrelated tasks, caused by the end of the financial year, i have not yet completed the dismantling and examination of the engine. When I do, I will bear in mind your comments. Having replaced exhaust guides in a previously owned R type, I am very interested in the inserts that you describe.Who supplies them? As to the machine shop question, Marty has been kind enough to give me a couple of leads that I can try. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1259 Registered: 4-2003 |
Just a note as all of the above applies. My notes are relevant to my R-Type B174UM. There is any number of really top-class machine shops around. They do have different quirks and methods, so do shop around before deciding on one. The first time I had the block in a tank at the machine shop it was a brine tank at Berco in Canberra. Berco promised that the camshaft bearing would not be damaged, and they were correct. That must have been in 1972. Like any decent motor machine shop, they were perfectly capable of reboring the cylinders and regrinding the crankshaft, but with provisos. Berco at first insisted that we have the crankshaft main bearing tunnel line bored to be sure that it was true. My father and I were horrified at that, wondering what it may have done to the general alignments and camshaft gear meshing. We rang York Motors. Alan at Yorks advised against it, and surprise, he had a special mandrel to test the tunnel. It is a solid steel rod exactly fitting the tunnel. With the bearing caps in place, the mandrel should slide through the tunnel, and it did. Berco accepted this and continued with the machining and dynamic balancing. The end result was that the motor was at last turbine-smooth. The next time was 1981. Alan couldn’t loan me a mandrel as he had given it away to the RROC(A) which could not find it. I avoided Berco this time as Repco agreed to do the job without one: they checked the alignment on their tunnel boring rig instead and it was fine. However, their proviso was that they remove all scale in a tank which dissolves whitemetal bearings and bronze, so I bought a set of camshaft bearings and exhaust guides. Repco fitted them and line bored them perfectly as they are not pre-sized shells. They really had a strong tank. I left the small cover attached to blank the provision for a mechanical fuel pump just by the dipstick thinking it was steel. It completely dissolved away. Repco also fitted austenitic steel exhaust valve seats to the block. No problem. They also fitted and bored genuine full-length liners, the main reason for the job, but I am sure that the ones from JP Pistons in Adelaide are every bit as good. The liners were touch and go as it had the lower liners fitted to bores 3 and 4 in the factory as many did if the casting was imperfect. That made it very difficult to machine the bore true but small enough to suit the Crewe liners, so JP may be a safer bet. In 1991 I had a cracked cylinder head, so found a good shop in Sydney, Con’s Performance Centre in Revesby. I think Con’s sons have renamed it Morris Performance Automotive, 59 Marigold St Revesby 2212 (02) 9774 4856 OR (02) 9773 0265 They can do practically everything. They were extremely good but a little slow and not cheap. They sent the head to a certain swindler in Sydney who posed as a Crewe expert repairer to have the spark plug inserts removed as the man promised that he could do it using a special Crewe tool without damaging them. All he did was hammer in a drift and rip them to shreds. The inserts needed to come out before the cracks could be welded followed by anti-porosity treatment. They made up a few sets of spark plug inserts to pattern in magnesium bronze and also a few new sets of exhaust valve guides to pattern in aluminium bronze. Making 36 to pattern doesn't cost much more than six as the main cost is in setting up the CNC software. Their alloy welding was superb. I bought a reamer and tap and fitted the spark plug inserts at home later. Con’s finished it all off by putting bronze inserts into the steel inlet valve guides. This is a fascinating process and so simple. He bored out the guides slightly in preparationm then inserted a length of special thin bronze tubing, and a machine pushed graded ball bearings of mirofine tolerances and increasing diameter down the holes to squeeze the bronze to yield the correct guide internal diameter. Then the ends of the bronze are cleaned up square, then he fitted the modern Teflon valve stem seals. It took about 2 minutes for each guide and there was no reaming of course. He offered to do the same to the exhaust guides at my home, but it was easier just to have new ones made and take them home. Paying for his time and travel to Woollahra and back would have far outweighed the cost of new ones too. I have a special tool for the exhaust guide removal and fitting and have consequently never had a problem with them. I hope that this is of interest. Clearly there are many good ways to skin a cat. RT. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1260 Registered: 4-2003 |
ps: Con promised me that the bronze valve guide inserts outlast plain steel guides by a factor of five, and the valve stems also as a result. He pointed out that the ball bearings surface-treat the inner surface of the inserts as they squeeze the bronze plastically to size, and that bronzes, presumably aluminium bronze in this case, are self lubricating as well. At the time he was doing mainly Mercedes-Benz work, and noted that without the bronze inserts many M-Bs had an atrocious record for valve stem and guide wear. He told me that he was simply not prepared to put new original valve guides into a M-B. When I showed him a new original Crewe guide and stem seal he couldn't stop laughing, especially when I informed him that even early Silver Spirits used them too. It is definitely not just a cheap quick fix. What's more it can be repeated without knocking those silly tapered inlet guides in and out of the alloy head. Also, if you have worn valve stems you can so easily reduce the diameter to match perfectly without needing new guides and reaming them undersize. | ||
| Marty Unregistered guest Posted From: c220-239-249-64.carlnfd3.nsw.optusnet.com.au |
Hi Richard, Morris Performance is one of my customers, I go there once a month, not a machine shop any more, general servicing only. Another guy who is very good at engine work, just around the corner from Morris, is Pat Purcell. He is at 9/13-14 Works Place, Milperra. 9792 4849. Pat is also one of my customers. He doesn't do any general servicing, only motor building. Mainly v8's. Cheers Marty (Message approved by david_gore) | ||
| James (Jim) Lee New User Username: graycar Post Number: 4 Registered: 8-2005 |
Hi Richard & Marty, Many thanks for your input. It will take some considerable time to complete this job but I will certainly let you know how I progress. Regards Jim. | ||
| Bill Vatter Frequent User Username: bill_vatter Post Number: 43 Registered: 9-2004 |
Jim, I'm in the US, and you're in Australia, so that might make a difference, but my machinist here says the valve guide insert is a common fix for engines that do not have separate pieces for guides but simply make a hole through a cast iron head. When that is worn, you put in the insert, something he has on the shelf for when it is called for. Cost less than $5 US per hole and works great. |
