wjajr and Fopar, thankyou! I'm still learning
.Forgot to mention has already had a port and polish by the previous owner.
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| question about oversize valves https://slantsix.org/forum/viewtopic.php?t=42480 |
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| Author: | robert west [ Tue Nov 02, 2010 7:15 pm ] |
| Post subject: | question about oversize valves |
thinking of installing oversize valves seeing engine is on stand.would like to use possibly 318 valves seeing I have small block moly retainers,single and dual springs.is there a length difference? I know the stem dia. is .372-.373 .also if it is better to use ford small blocks what motor becouse friends of mine uses to put 302 heads on there 289"s for better proformance.thanks robert |
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| Author: | DusterIdiot [ Tue Nov 02, 2010 7:30 pm ] |
| Post subject: | Best bet... |
For the price just get the valves, springs and retainers from enginebldr on ebay...price is right and they will be easy to install by your machinist... -D.Idiot |
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| Author: | Joshie225 [ Tue Nov 02, 2010 7:31 pm ] |
| Post subject: | |
Small block valves are too long. You can use LA engine springs and retainers with the stock valves. There are oversize 1.70/1.44" valves available in the proper length. Others have used Ford 300ci 6 cylinder valves as they are the proper length, Chevy valves and others. It's no trick to put in smaller guides. The valve size you can effectively use depends upon the cylinder bore. If you're still at standard the 1.70/1.44" is about right. |
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| Author: | robert west [ Wed Nov 03, 2010 7:23 pm ] |
| Post subject: | |
thanks all,the motor is .040 over so size should be good.so I will check in with them both.thanks again robert |
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| Author: | 66aCUDA [ Thu Nov 04, 2010 8:05 am ] |
| Post subject: | |
Robert As one who has Both over size vales 1.70/1.44 and 1.78/1.50(Ford 300). You will want to stay with the 1.70/1.44. The .040 is really too small for the larger Ford valves. Frank |
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| Author: | robert west [ Sat Nov 06, 2010 5:41 am ] |
| Post subject: | |
thanks for the info. robert |
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| Author: | Brussell [ Sat Nov 06, 2010 7:16 am ] |
| Post subject: | |
Might be Hi-Jacking this a little bit. but is it worth getting the oversized valves if I'm not going to bore the cylinder of my 225? has 350 holley, 10:1 compression, extractors and new ignition stuff with big coil... Cheers. |
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| Author: | Fopar [ Sat Nov 06, 2010 8:08 am ] |
| Post subject: | |
Point to remember is the head was designed for the 170 motor and was not changed for the 225. Richard |
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| Author: | wjajr [ Sat Nov 06, 2010 10:44 am ] |
| Post subject: | |
Brussell: Quote: Might be Hi-Jacking this a little bit. but is it worth getting the oversized valves if I'm not going to bore the cylinder of my 225? has 350 holley, 10:1 compression, extractors and new ignition stuff with big coil...
Yes, your engine will perk up with better breathing, particularly with the upgraded equipment you already have installed & its high compression ratio. If you do install larger valves I would recommend gasket matching, and cleaning up the intake & head passages by removing the casting warts, and smoothing up the bowls with a bit of light porting. Doc has written several articles on how to do this work. Less is more when doing this. I ported out my head when the over sized valves were installed a few years ago. The difference was immediately noticeable when backing out of the garage after the first start. |
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| Author: | Brussell [ Sat Nov 06, 2010 3:26 pm ] |
| Post subject: | |
wjajr and Fopar, thankyou! I'm still learning .Forgot to mention has already had a port and polish by the previous owner. |
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| Author: | wjajr [ Sat Nov 06, 2010 5:21 pm ] |
| Post subject: | |
Brussell: Quote: Forgot to mention has already had a port and polish by the previous owner.
66acuda:Quote: You will want to stay with the 1.77/1.44. The .040 is really too small for the larger Ford valves.
Well, the job is almost done, what are you waitng for?
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| Author: | 66aCUDA [ Sun Nov 07, 2010 5:48 am ] |
| Post subject: | |
Sorry guys my fingers got the best of me those valves from Engine builder are 1.70 not 1.77. I went back and edited my post. Frank 
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| Author: | wjajr [ Sun Nov 07, 2010 6:29 am ] |
| Post subject: | |
Frank, I’m not going to hang you for seven hundredths of an inch. I knew exactly what you were referring to, and didn’t notice the typo… Must be an age thing. LOL Bill |
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| Author: | robert west [ Sun Nov 07, 2010 8:19 am ] |
| Post subject: | |
thanks for the reply all,I know this motor should really wake up with the added head flow.the only reason I had not did it before is I had a firebird with a built 400 and the intake and exhaust valves almost touched,it overheated on me one time and cracked the heads.I have a extra head here I've was studying and can see where the flo can be increased.should be fun. robert |
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| Author: | dustertech2000 [ Tue Nov 09, 2010 8:39 pm ] |
| Post subject: | |
i'm running 1.80/1.50 valves with .030 over bore and have no clearance issues |
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