http://www.edelbrock.com/automotive_...erformer.shtml


will these work on a 305 tpi engine??? this engine is for my brother and he does not want a 350 block

 

no the valves are to big . you need heads with 1.94 / 1.50 valves .
a set of vortec heads change the springs for bigger lift an your set .

 

Probably not...

The valves are so large that they will probably not be entirely inside the cyl. Bad things happen when a valve tries to open and it hits the top of the block.

Even if they "fit", they will be EXTREMELY CLOSE to the cyl wall. No flow can occur through a tiny crack where parts almost touch. But, the flow into a head is greatest on the outside wall of the port, coming in through the valve on the side away from the exhaust and swirling around the spark plug side toward the plug; meaning, the HIGHEST FLOW PART of the valve's area is what will be blocked; meaning, the net-net result of using valves that are too large, is potentially WORSE flow than stock 305 heads would have had in the same situation.

The 305 isn't a good choice for hot-rodding, precisely because of the small bore. However the best thing you can do is to put slightly larger intake valves into his stock 081 heads, the correct size being, 1.94". Then open up the throat of the port right behind the valve to about 85% of the new valve's area, WITHOUT lowering the floor of the port and WITHOUT changing the basic shape. Just smooth it out back there and take out the weird angles from where the factory jammed the cutter into it. Smooth the guide, which is now a round nub, into a sort of "teardrop" or "airfoil" like shape. Use valves with undercut stems such as the Manley Street FLow ones. Lay back the chamber "wall" gently. Don't bother with the part of the port near the intake manifold flange, that isn't where any restriction is.





Here's a pic of an 081 chamber with the area in question laid back (this one is more than you'll need because it was for a 350); and a pic of an intake port cross-section. From the 2nd one it's pretty obvious where the gains all come from and what it just a total waste of time on non-functional eye candy.

Remove all sharp edges from the chamber so there's no possibility of any thin red-hot metal sticking out in there to cause detonation. You can de-roughen the chamber roof but "polishing" is not necessary or effective. Just a waste of perfectly good abrasive.

On the exhaust side, you should follow the same rule of working in the bowl behind the valve. You can port the roof gently and smooth the guide but don't make it too thin. "Polishing" is another waste of time that produces no results, don't bother with that.

 

I was under the impression that a 2.02 valve would fit in a 350 standard bore, you just have to limit the valve lift to at or below .400? The valve shrouding would be tremendous though, giving worse airflow than a 1.94 valve.

 

it will fit a 350 block but you said a 305 block with 350 heads ...

 

I meant 305.

 

thanks for the input guys so do what do u guys think of these?? r they good
http://www.summitracing.com/parts/TFS-30310001/