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| jamesdavo |
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Could i get some advice on a safe amount to machine off a tickford head.
The head will be mildly ported with a Crow 519 cam,looking at 30-40 thou to get the compression up a bit.just a little worried about piston/valve clearance. thanks. |
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| racer |
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I have a ported head for sale if interested. It has the larger xr6 exhaust valves and xr6 valve spring. It would only need a shave to mate with the new head gasket. If your interested PM ME.
_________________ FORD EL 4.0L. Crow cam, T.I Performance J3 Chip, Vernier cam gear, SPR ported head, 68mm TB, AU head gasket + ARP studs, AU injectors, Pacey 4480, High flow cat, Shift kit, Stallie, 3:73 TrueTrac. |
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| creeture3 |
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Be careful how much you take of, if you remove too much, the cam chain tensioner wont work, as it will be extended too far
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| roughredXR6 |
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creeture3 wrote: Be careful how much you take of, if you remove too much, the cam chain tensioner wont work, as it will be extended too far Nah, just chop it to the limit. Mine is shaved so far the inlet seats even got trimmed. Couple of washers to pack out the tensioner till you get a new timing kit, worked for me. No issues with valve clearances, even with a big cam. You will have to slot one of the holes in the power steering pump bracket though. Although I do recommend an adjustable cam gear as the lower you go, the more you timing will be out. Oh, and don't forget, smaller gap means bigger compression, means higher octane fuel to prevent pinging your motor to death. Unless you know how to set up a good water injection system.............. But seriously, just give it a good skim and fit an AU multi layer steel gasket. The little rectangular pads on the corners are the factory limit indicators.
_________________ Ported ED XR6 head shaved too much, AU gasket, custom Crow Cam, Pacemaker 4480's, 5-speed conversion, billet aluminium flywheel, GT clutch, T.I. Performance J3 chip, custom water/methanol injection, modified BA throttle body. Paint&Panel by Barbed Wire Fence. |
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| creeture3 |
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Quote: Couple of washers to pack out the tensioner till you get a new timing kit, How do you pack out the tensioner, and, if you bought another timing kit, wouldn't the chain length be the same? |
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| roughredXR6 |
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Chains stretch, guides wear.
I used two stainless steel washers between the tensioner body and the filter housing to give the tensioner an extra few mm of travel. I don't recommend this as a fix, but, it worked for me. Ran it like that for about 2 months with no problems. Now have a new kit installed, no washers, still have a bit of adjustment left.
_________________ Ported ED XR6 head shaved too much, AU gasket, custom Crow Cam, Pacemaker 4480's, 5-speed conversion, billet aluminium flywheel, GT clutch, T.I. Performance J3 chip, custom water/methanol injection, modified BA throttle body. Paint&Panel by Barbed Wire Fence. |
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| 3.9from hell |
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piston to valve clearance is all down to the cam specs. lift plays a role but LSA is more important. my 600thou lift cam has enough clearance because of its wide 114.5 lsa. where as my previous cam had less clearance at 111lsa with only 530thou lift
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| jamesdavo |
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Thanks for that only .500 lift and 114 Lsa so we are going with 30 though.
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| roughredXR6 |
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3.9from hell wrote: piston to valve clearance is all down to the cam specs. lift plays a role but LSA is more important. my 600thou lift cam has enough clearance because of its wide 114.5 lsa. where as my previous cam had less clearance at 111lsa with only 530thou lift I agree. The wilder the cam, the more important it is to check piston to valve clearance, and cam timing. For example I found with my current cam (advertised 282 inlet / 288 exhaust, 110 lsa, 500thou lift) I have plenty of room on the exhaust side but I'm on the limit on the inlet. Inlet lobe lift at TDC is .054" on overlap and with the head shaved to the seat, the valve hangs down into the relief cuts in the pistons. Basically if my timing is more than a couple of degrees advanced, the pistons and valves become one. This is a rather extreme setup though, requiring minimum 98oct fuel and a custom made 300psi water injection setup. Most street friendly cams will have heaps of clearance.
_________________ Ported ED XR6 head shaved too much, AU gasket, custom Crow Cam, Pacemaker 4480's, 5-speed conversion, billet aluminium flywheel, GT clutch, T.I. Performance J3 chip, custom water/methanol injection, modified BA throttle body. Paint&Panel by Barbed Wire Fence. |
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