Thread: HELP!! my 427 runs like a two stroke

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Would depend on what the chamber size is on the oval heads, the flat top pistons are killing the compression so a pair of oval port heads with the same cc or larger won't do much for improvement. For what it's worth, I've never build or had built an engine that made poop for power below 2,000 rpm, always aimed for the power to come in at about 2,000 and then the engine starts pulling good. Anything 2,000 or thereabouts is barely a cruise rpm, even with the overdrive transmissions and lazy rear gears of today's cars.....

What would be a good cc chamber to run with flat top pistons? The 462 is built with the oval port heads oversized valves 10.5/1 dome speed pro pistons scat i beam rods lunati 590 lift cam and 1.6 roller rockers but when you spin it over with a ratchet it has a stiff spot in it and havent messed with it to figure it out and if i change motors i will have a flywheel issue unless i can have the balanced changed on it. just not quite sure which motor would be better in the long run

Originally Posted by Dave Severson

Would depend on what the chamber size is on the oval heads, the flat top pistons are killing the compression so a pair of oval port heads with the same cc or larger won't do much for improvement. For what it's worth, I've never build or had built an engine that made poop for power below 2,000 rpm, always aimed for the power to come in at about 2,000 and then the engine starts pulling good. Anything 2,000 or thereabouts is barely a cruise rpm, even with the overdrive transmissions and lazy rear gears of today's cars.....

well yes and no dave ..you ford ... guy you rec port heads will not work that hot in low rpm engine +big cam ....small CID...... two heads with the same chamber size with big port runner and smaller port runners .the smaller port s will work better in this case the O ports you may get away with to big of cam .but not a big cam. low CR + big intake runner for the street = turd