Hi guys, spring is just around the corner, and I'm working hard to get my engine together for the warm weather...I was just wondering where you ghuys go as a source for oversize valves..I was thinking about using factory 318 valves.. because my buddy has some low mile ones hanging around.. everything looks good except the 318 valves are .100" longer, will this mess up my rocker geometry with stock rockers? I know there are other alternatives.. but I'm not clear on what they are..any help would be appreciated there... this will be a long rod/2.2 buildup with 10.5-1 comp and 3.504" (1.5mm overbore) pistons.. so I should have some room to unshroud the valves or possibly use larger ones.. let me know what you reccomned... thanks for the help Dan

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The worst mistake a boss can make, is not say "well done"

I know of several people who use/are going to use Ford 300 valves with 340 valve springs. I believe they are the same length as stock slant valves. Somebody will chime in on the diminsions I'm sure.

purchase ford 300 cid 6 cyl valves and locks I beleive they are 1.776/1.565 these are the biggest valves you can put in a slant also you will need new guides as these are 11/32 inch valve stems and a new 3 angle valve job plus some porting to maximise your gains also some say you need to bore .060 over to fit these I cant say for sure but you already went that far anyway. if this is a race motor I sugest cox bros 1.6 roller rockers double roller timing chain and at least a .500 lift cam you should be getting plenty of power with that

289 Ford valves are very good choices as they are within 0.020" of the Slant length and are like 1.77/1.46. SBC valves (1.72/1.50) are also very good and will work well with that bore size. Don't try to use bigger than 1.54 on exh or 1.80 intake (absolute max) or you will be shrouding even with that bore. I have the SBC valves in both my Dart heads and they work well and have the best range of sizes/cuts available.

Most of the hardcore racers (read - THE fastest ones) use smaller valves than those - more like the SBC/F valves I mentioned above. All will require 11/32 guides and best to put in hardened exh seats for a hardcore streeter.

Make sure to rough cut the big valve seats, then go back in and blend the bowls. I didn't do this on mine, but should help a lot according to the 10 sec guys. Don't bother hacking away port material, just blend things in.

Happy Building,

Lou

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Home of Slant6-powered fun machines since 1988

Here's what we used on our 0.060" over 2.2 rod engine:

Manley intake valves, S-1670 1.78"
Manley exhaust valves, A-1669 1.45"
Both of these came from PAW and fit 289/302 Ford's
11/32" bronze guides
Comp Cam springs and retainers, spring #995 & retainer #740
Comp Cams custom grind #6610 intake, and #6611 exhaust with 108° lobe separation installed at 106/108±

Machine shop had to just kiss the exhaust valves for length. Stock pushrods and rockers with grooved rocker shaft and grooved cam were used. Valve geometry was perfect.
Head was heavily ported and new 3 angle valve job after valve guides were fitted.

Head has about a 35-40cc chamber, and with #1291 UEM pistons that were cut down 0.100", gives about 10:1 compression ratio. Broke the first set of pistons that were #268 KB's, and could not replace them! Out of stock all over the country. Detonated bad and butted the rings.

Bottom end uses all the oil mods, tray, HV pump with std spring, ARP rod bolts, balanced parts and cross drilled crank. Installed risers in lifter bay and run 1 quart extra oil. Also run tall Ford truck filter (2 quart).

Car is 4 dr Val, with auto, 3600 rpm converter, 3.91 gears and PS. Will pull hard past 6,000 rpm but we shift at 5,800+. Car is not yet fully sorted out, but we expect very low 14's on street slicks and open pipe.

You won't know what length valve you need until you know what valve lift. More lift = longer valve. Proper length is: stock length + 1/2 (new lift - stock lift).

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