Valve change input

[Anonymous]

I was wondering if on top of my mostly stock engine except pertronix and H/W 5200 that is giving my problems, if changing the stock valves to the FSPP 1.75 intake and 1.5 exaust valves would give any performance gains on the stock engine. Just wondering because this seems simple to do without alot of other stuff done.

Thanks,
Chris

 

[Anonymous]

It's a little more complex that just pulling out the old valves and sticking the new ones in. A machine shop will have to cut out the old seats and install new ones... this upgrade is best done when it's time for a whole valve job. May as well do some pocket porting, port the exhaust, do a port divider... and heck - fit that 5200 directly to the log while your at it. Then you can take full advantage of those new shiny valves.

 

[mugsy]

To replace the valves you would have to pull the head, and then you are half way to a cam change any way. So it would be cheaper to replace the cam and forget the valve size; I would think a bigger cam would be a better way to increase breathing on a per dollar basis.

Rememeber the 3 C'c of performance: Carb, Cam and Compression. Do those first, THEN do the fun/exotic stuff. And if you pull the head then you can accurately measure the compression ratio and mill the head accordingly. Also do a three angle valve job while you have the head in for milling!

 

[Falcon62]

I was wondering if on top of my mostly stock engine except pertronix and H/W 5200 that is giving my problems, if changing the stock valves to the FSPP 1.75 intake and 1.5 exaust valves would give any performance gains on the stock engine. Just wondering because this seems simple to do without alot of other stuff done.

Your comment about upgrading to the 68 and later distributor being too expensive tells me you don't want to do this right now. The valves alone will cost way more than a distributor upgrade not including the machine work to have them installed.

Your need to focus your energy and finances on solving your drivability problem before you add another variable. Just my $.02.

 

[Anonymous]

Yea, in no way was i going to be able to do this, i was just wondering what kind of extra performance the larger valves could give you, but along with those everything else would need to be done too. As I am still a student I'm just trying to learn as much as I can to get this done right and get good performance.