Is it bad if?

[tylerrocks]

ok so I just had some machine work done to my heads, had the valve seat resurfaced. Got the engine running today drove it ~30 miles. Got the carb tuned and timing set. I made a dozen or so pulls to ~3000 rpm, all felt great. Then made a first, second gear pull to ~4500-5000 rpm (didn't look) it pulled like an ape. Then I attempted a pull and got some mild spuddering. My question is: does machine work (valve seat) need to broken in? Hope i didn't make a stupid mistake.

Tyler

 

[D.Hearne]

Check your float settings on the carb. And make sure the fuel filter isn't plugged. Sounds like you may have run short on fuel at that point. No run in time needed on valves, as long as the machinist lapped them in good.

 

[tylerrocks]

Thanks D. I was hoping for a carb hiccup

 

[D.Hearne]

One other thing----what valve springs are you running on those GT40P heads ? Could be valve float, that's going to happen at about 5500 rpms (or less) if you've got the stock springs on those heads.

 

[tylerrocks]

not sure about the springs except that the shop measured them to be OK for my lift. Dual springs

 

[D.Hearne]

That could be it then. I've got Crane springs on the E7 heads in my Ranger and it floats the valves at 5500-6000. I'm a little fuzzy on what springs these are, I thought I had ordered for a hyd roller, but might have gotten the ones for a hyd flat tappet, anyway, they're stiffer than the stock springs. 5500-6500 is about the limit for the stock roller lifters as for float. In my 331, I went with Crane's replacements for the O.E. rollers, it'll rev to 7500 with the Canfield head's springs.