Re: [Spits] Engine rebuild: What to ask and say to the machine shop? -and Happy 4th!
Nick, I went with the Fast Road Profile Cam from Nigel at SpitBits. It is pretty close to the one recommended in John Davies' article called Skimming Your Head for a Higher Compression Ratio. That makes a huge difference and puts all that extra compression to work. With the old cam, I could barely make it to redline. With the Fast road cam it pulls all the way past redline and then some... I also added the oil cooler from Spitbits. If you're going to add it, skip the rubber hoses and go with the Stainless hoses. The rubber ones lasted less than 500 miles before coming apart. Looking back, I wish I would have replaced the valves with the Large Intake Valve 1.44 and Large Exhaust Valve 1.23. RazorBob suggested that I do that and I think he was right. Gene Eighmy NASS #275 '79 Spitfire 1500 Birmingham, AL ___ Spitfires mailing list Spitfires@autox.team.net http://autox.team.net/mailman/listinfo/spitfires
Re: [Spits] Engine rebuild: What to ask and say to the machine shop? -and Happy 4th!
Nick, -do machine shops expect the crank removed, or would they prefer it in? Leave the crank in. It must be reassembled in the exact same order and orientation. If I were you, I would mark each bearing clamp with a metal punch. Punch the front with one mark, the middle with two and the rear with three, etc. Then take a detailed picture so you can verify that they put it back together properly. -what about the camshaft, in or out? I upgraded to a better camshaft and included it so they could check the float. I don't remember if they had to do anything but I included it just in case. -do they expect to be told what to grind it to, or will they measure and decide? My machinists said they could skim the head for 9.5:1 (premium gas). Fortunately, I measured everything possible before taking it to the machine shop. When I got it back, I measured and verified everything and noticed that they only took 0.010 off the deck and 0.010 off the head. When I called them on it, they said they didn't know how to cc a head and asked how much I wanted off... I think they know how to do it but it is more of a liability issue. For more info check out my woes: http://webpages.charter.net/eighmy/spitfire/ -should I be giving them the head as well to install new valve guides and skim? Yes. While you have it apart, you will want to reseat your valves which will improve your performance. They will need all of it. The machine shop I've chosen comes recommended, has worked on Spits and LBCs in general, and is located next door to a mechanic that works on LBCs and others. I've never used that mechanic, but they also come recommended. Should I be taking my own measurements and telling them what to grind it to, or letting them know the over-bore sizes available and let them get to it!? Will they supply the pistons and rings? When I rebuilt mine, I ordered flat-top pistons to bring it up to UK specs. At the time, 0.020 and 0.050/60 were still available. As you can tell by now I'm sure, the big question is: what do I ask and say to the machine shop, and what should I do to prepare before-hand? Figure out what you want to accomplish first. Do you want stock US/Canada performance? Or do you want UK performance? Or a race fuel powered rocket? It is VERY IMPORTANT that it all goes back together in the same order. Do not take a box of parts to the machinist without knowing how it all goes back together. Mark parts and take pictures to document. Trust but verify your machinist. Measure twice... you can only cut once... Gene Eighmy Birmingham, AL ___ Spitfires mailing list Spitfires@autox.team.net http://autox.team.net/mailman/listinfo/spitfires
Re: [Spits] Engine rebuild: What to ask and say to the machine shop? -and Happy 4th!
Thanks Gene. Great advice. I enjoyed your web page, and well remember the novel solution of using piano wire to form a spring for the master cylinder, and the other challenges you overcame. I'm hoping to phone two machine shops tomorrow, to find out if any will work with me. I also spoke to Ted S on Saturday morning. His offer of doing the work including assembly is extremely tempting, and would certainly guarantee success. I'm still hung up on doing some of the work myself though. Just out of curiosity, which cam did you go with, and are you happy with it? Many thanks Nick Moseley (NASS 278) 76-81 Spits, near Vancouver B.C. ___ Spitfires mailing list Spitfires@autox.team.net http://autox.team.net/mailman/listinfo/spitfires
[Spits] Engine rebuild: What to ask and say to the machine shop? -and Happy 4th!
Happy 4th to all my neighbors to the South! Sorry for the cross-posts! I have a project engine for a home rebuild, partly to save $s, and partly for the challenge. Here is what I gather so far: It is a late 1493cc engine reputedly had about 75,000 miles on it (FM132xxx I think). The oil filter had mileage at the last oil change written on the end, which along with other signs, would indicate the former owner took care of it. Engine was removed from an accident damaged car. Yet, the oil in it was black as coal. Whereas when the other pistons were removed the rings sprang out and expanded, on #4 cyl the rings stayed contracted into their slots, seemingly stuck together with a paste of oil and carbon. (Which explains the black oil). The crank journal under #2 cyl has visible but not feel-able (with fingertip) grooves, the others have wear but less. There is a feel-able (finger-tip again) wear ridge at the top of the cylinders. I've tried measuring, and get results varying from 2.90 at the very top, down to 2.893 at the bottom of a cylinder. There are variations, probably due to my lack of skill, I've never used the digital caliper and other thingy with axles on springs, before. On the head, intake and exhaust valves on #2 cyl. were removed. There was visible wear on the intake valve stem and some lateral movement, but neither on the exhaust valve. So questions: -do machine shops expect the crank removed, or would they prefer it in? -what about the camshaft, in or out? -do they expect to be told what to grind it to, or will they measure and decide? -should I be giving them the head as well to install new valve guides and skim? The machine shop I've chosen comes recommended, has worked on Spits and LBCs in general, and is located next door to a mechanic that works on LBCs and others. I've never used that mechanic, but they also come recommended. Should I be taking my own measurements and telling them what to grind it to, or letting them know the over-bore sizes available and let them get to it!? As you can tell by now I'm sure, the big question is: what do I ask and say to the machine shop, and what should I do to prepare before-hand? For those curious, I hope to use a rebuild kit available here: http://www.sportscarsupplies.com/catalogue.asp?model=Spitfire%20/%20GT6 The $3,500. odd that a lister on another list paid for a rebuild is beyond me. Many thanks for all suggestions, Nick Moseley, NASS #278 76-81 Spits , Near Vancouver B.C. ___ Spitfires mailing list Spitfires@autox.team.net http://autox.team.net/mailman/listinfo/spitfires