Carl Posted March 7, 2001 Share Posted March 7, 2001 I took the plunge last year and purchased my first seven, and have had wicked fun ever since. The car that I am running is an 1990 crossflow with a new Burton Head in 1996, and 286 cams. Unfortunatetly, the car puffs out oil when it starts. The engine does not appear to burn anymore oil once it is operating. I have heard that this could be due to perished valve oil seals, or wornvalve guides letting oil from the rocker down into the cylinder. Warn value guides would seem a bit drastic as the head is still quite young. The engine has now covered approximately 45,000 without any major rebuilds within this period. Does anyone have any other causes to the problem? Look forward to your replies Carl Link to comment Share on other sites More sharing options...
I reply to every thread Posted March 7, 2001 Share Posted March 7, 2001 If by "it puffs out oil when started" you mean that you get oil smoke on starting - and at no other time - it'll be down to the fact that you've got a X-flow. My understanding is that it's almost part of the design that some oil gets into the bores while standing. Could be oil seals as well. My X-flow did it from 0 miles to 12,000 with no other apparent ill effects. Link to comment Share on other sites More sharing options...
I reply to every thread Posted March 7, 2001 Share Posted March 7, 2001 Ps if you're running a Caterham bottom end and Pistons I understand that the rings don't last that long. 45,000 miles is a fair amount for a X-Flow. It's not a Honda V-TEC! Link to comment Share on other sites More sharing options...
Mat Norris Posted March 7, 2001 Share Posted March 7, 2001 I had the same problem. I believe it is due to oil running down the valve stems when the engine is not running and is quite common with x/f engines using modified heads. I'm not an expert but as i was not using any oil during normal running, I think I believe the people I spoke to. However, my engine had only done about 1000 miles with perfect compression test results etc. As your's has covered 45K it may be due to wear of the stems, guides or seals as suggested. For the ultimate advice, your best bet is Roger King! Good luck Link to comment Share on other sites More sharing options...
I.Mupferit Posted March 7, 2001 Share Posted March 7, 2001 The X/Flow I had was fitted with double valve springs which prevented the fitting of the valve stem seals. Consequently my engine did exactly the same thing on start-up but used virtually no oil thereafter. I wouldn't worry about it. Brent Link to comment Share on other sites More sharing options...
Leadership Team Mcalvert Posted March 7, 2001 Leadership Team Share Posted March 7, 2001 There are valve stem seals which can be used even with the double springs. James Whiting fitted some to my 1700 Crossflow fairly cheaply last year. Regards, Michael. Link to comment Share on other sites More sharing options...
STEVE GILBERT Posted March 8, 2001 Share Posted March 8, 2001 Just modded my Xflow with double valve spring 'Kent Camms' Valve Stem oil seals. You can get them from Caterham but you will need to degrease and then Superglue them to the Head casting to keep them in place. If you think about it how else can oil get into the cylinder bores. All.Knowing1@talk21.com Link to comment Share on other sites More sharing options...
Violet Elizabeth Posted March 8, 2001 Share Posted March 8, 2001 Had my Valve stem seals replaced by JW a couple of weeks ago. Can someone explain what they are ? Glueing was mentioned, whats all that about ? Link to comment Share on other sites More sharing options...
STEVE GILBERT Posted March 8, 2001 Share Posted March 8, 2001 All round crap design on the Xflow head where the Stem seals do not fit securely to the Head and hence move up and down as the Valves open and close. The std Ford items are about 3mm diameter to big to even attempt a head fit and I can't see them ever being any good, hence the use of the Kent item. Trouble with the Kent seal is it fits really snug on both stem and head and can't be trusted to stay on the casting, hence Superglue. All.Knowing1@talk21.com Link to comment Share on other sites More sharing options...
Maccers Posted March 8, 2001 Share Posted March 8, 2001 Same here, my 1700 X-Flow has hit 12,000 and blows oil out when first started. It's not losing oil, ie none in catch tank, and none on garage floor. I once had my Mini engine re-built as a 1380cc (from 1275cc) with new pistons, rings - the lot, and it blew oil out when turned over from cold. RM. Link to comment Share on other sites More sharing options...
Taran Las Posted March 8, 2001 Share Posted March 8, 2001 My Crossflow had covered 23,000 miles and was showing signs of wear. So the engine was removed and stripped. The valve to guide clearances were approx 0.003". Replacement Bronze guides were made and reamed to provide a working clearance of 0.0005" and a lip machined at the top to accomodate the valve seal. This appears to be working OK so far. Link to comment Share on other sites More sharing options...
kim Posted March 8, 2001 Share Posted March 8, 2001 When I fill my 14000miles 1600 Xflow with oil to the max mark after a relatively hard blast in the country the catch tank seems to collect about 1/2pint. This continues until the oil level finally settles at about 1/3 from min level. What's happening and is this normal ? Thanks Kim Link to comment Share on other sites More sharing options...
Maccers Posted March 8, 2001 Share Posted March 8, 2001 Oil in the catch tank is blowing out of the crank case breather under high pressure, when you give it some hard revs. You must be really booting it for it to fill up that much!!! RM. Link to comment Share on other sites More sharing options...
JKJ Posted March 8, 2001 Share Posted March 8, 2001 I have a big black stain on either side of my garage walls, depending on which way around the car is parked, caused on starting the car up. As suggested if there is no further smoke signals once running then don't worry. Link to comment Share on other sites More sharing options...
Roger King Posted March 9, 2001 Share Posted March 9, 2001 The valve stem seal used by Caterham is actually for a Mini (it's the same as the Kent Cams one). This seal has a lip around the inside at the bottom that is designed to fit into a locating groove. Needless to say, the Crossflow does not have this groove with the result that the stem seal is very prone to moving up and down with the valve. This stops it from working! Another potential problem is incompatability between the valve material and the valve guide. It is quite common to find valves made of E214N (an excellent material) running in cast iron guides. This usually leads to rapid wear. The answer here is to chrome plate the valve stem (tufftriding is an alternative), or to fit bronze guides. I have no way of knowing what material combination you have Carl, but it is worth investigating. The solution that we adopt is to discard the Mini stem seal (which is not that efficient anyway), machine the tops of the guides to reduce their diameter and then use a modern (and much more efficient) stem seal. These will quite happily sit inside a double valve spring. It is also of course possible that you have oil finding it's way past the piston rings. If you are running 1300ccm Escort pistons (as per Supersprint) you can expect this to start happening at around 15000 miles, simply because they are being asked to work in an environment way beyond their design limits. Solution is to fit forged pistons. If your engine has done 45000 miles with these pistons it has done VERY well. Edited by - roger king on 9 Mar 2001 10:59:51 Link to comment Share on other sites More sharing options...
I.Mupferit Posted March 9, 2001 Share Posted March 9, 2001 Blimey Roger you're doing an excellent sales job for forged pistons, do you have shares in the manufacturer? smile.gif Link to comment Share on other sites More sharing options...
Carl Posted March 9, 2001 Author Share Posted March 9, 2001 Thanks for all the responses. I have learnt that my engine is not alone in puffing smoke out on start up. This appears to be a trait of old engine technology. Anyway this gives me the excuse not to rebuild the top end which I was not looking forward to. I will make the most of this years weather (not much of it up here in Newcastle) and rebuild the engine next winter. PS Anyone going to Le Man from the North East with the club? It will be more fun in convoy. Thanks Again Carl Link to comment Share on other sites More sharing options...
Roger King Posted March 9, 2001 Share Posted March 9, 2001 NO!, it's simply that they are so superior to the original item. Link to comment Share on other sites More sharing options...
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