3 angle valves and manifold matching

st182 Part of things 'yota man Posts: 585	3 angle valves and manifold matching st182 @st182
	Mar 30, 2007 1:27:38 GMT Select Post Deselect Post Link to Post Back to Top
	street> tou'll know what lapping is when you have a go at it- bring on the blisters! I'll have 16 to do soon if i get my ass in gear with my head project...... As for "polishing" ports, I see some folks call it a waste of time. Maybe one of you could help me out? The problem I have is that on the head I'm doing, there is a nasty mismatch in each port, where the boring tool has been into the throat of the port, concentric to the valve guide- so valve end. I have ground this out, and also taken out the casting seams at the manifold end. Now if I leave the finish as it is, then I will have an original "cast" rouch finish on some of the central area of the port, and a smoother finish where I have worked it. So what I have done with the first one is just take down the finish over the rest of the port to match- is this a waste of time?? Its a bit of a blow if it is a waste of time, as i've already done one and obviously want them all to match.........
	Dan '93 JZA80 '79 TA40 '99 SCP10

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akku Probably posted too much Posts: 15,870	3 angle valves and manifold matching akku @alistairk
	Mar 30, 2007 7:52:52 GMT Select Post Deselect Post Link to Post Back to Top
	many things depend on the head/manifold/ports/valves you have already. Matching the inlet is quite important if you put an ali 4 barrel intake on a 318 mopar using the stock heads as the ports are actually a fair bit lower... a bit of epoxy to raise them does wonders. I would have thought that you want a consistant finish all the way down the port regardless. I have heard plenty of arguements about the validity of port polishing. Some say it gives a benefit, some say it doesn't and some say it harms performance. one of the mags had 6 or 7 guys in the performance engine building business and asked them and even they didn't agree. There is some suggestion that polishing the chamber and exhaust port rejects carbon buildup and reduces risk of detonation when running marginal compression and timing. But these days most people would say that ceramic coating does a better job of that.... Look at the stuff done for Enginemasters or whatever and see how many polished ports you see.... erm... any? Thats where I'm taking my cue from. I saw some flow data which was published in one of the mags recently and the back cutting of valves really does make a difference. So go for it.
	1941 Wolseley Not Rod - 1956 Humber Hawk - 1957 Daimler Conquest - 1966 Buick LeSabre - 1968 Plymouth Sport Fury - 1968 Ford Galaxie - 1969 Ford Country Squire - 1969 Mercury Marquis - 1970 Morris Minor - 1970 Buick Skylark - 1970 Ford Galaxie - 1971 Ford Galaxie - 1976 Continental Mark IV - 1976 Ford Capri - 1994 Ford Fiesta

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bstardchild Club Retro Rides Member Posts: 14,965 Club RR Member Number: 71	3 angle valves and manifold matching bstardchild @bstardchild Club Retro Rides Member 71
	Mar 30, 2007 9:13:18 GMT Select Post Deselect Post Link to Post Back to Top
	My local machinist charges Valve Seats - Std cut £1.85 - Multi Angle seats £3.25 £1.40 extra per valve seat Valves - Std re face £1.85 - re- face with back cut £2.85 £1.00 extra per valve


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VW Posted hell of a lot Posts: 6,000	3 angle valves and manifold matching VW @vw
	Mar 30, 2007 9:44:03 GMT Select Post Deselect Post Link to Post Back to Top
	I guess ill get the valves out. If the seats are servicable with just a good lapping ill leave em. If they need recutting i might as well 3 angle them.


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