Buzznut is right, flat-top pistons with a 461 head, 64 cc chamber, gives 10;5 compression ration. You can get thicker gaskets from Victor I think. go with a sandwich style gasket. You will need to run mid or premium gas, no 87. I fthe car is indeed 1900 lbs, you can back off the timing to prevent ping. Also, look at changing the ratios of the rocker, especially on the exhaust, it will make your 331 sing! QUOTE=Buzznut;4221040]461's are closed chambered heads...used in high compression applications. As far as I've ever known you need dished pistons or thicker head gaskets or both to bring the compression down below 10:1...[/QUOTE]
Here's a very good rule of thumb: every .010 extra thickness of gasket will drop you about .25 in compression (with regards to a 4 inch bore). So, with my combo having a .030 gasket at 10.25:1 compression, if I went to .040 then I'd be at 10:1 and at a .050 gasket I'd be at approximately 9.75:1. Short answer, no...you didn't screw up at all. Also, you can do the same thing by putting the plugs in the hole. So, if you start at zero deck height/clearance and you go to .010 in the hole or .020 in the hole you'll drop .25 or .50 in compression respectively. The problem is that doing this is MUCH more complex and expensive than the gasket option is. And bigdaddyo is right about the sandwich style gaskets...especially when you are going thicker to decrease CR.
Whew!!! So with my setup, stock block (not decked), stock pistons, 461 heads, corvette 2 1/2" exhaust manifolds, comp cam kit with 262 duration and .462/.462 valve lift, performer manifold and edelbrock carb, what gasket thickness do y'all recommend? Do y'all have a link to these sandwich style gaskets? I've searched the web but am not sure what is sandwich style and what is not. Thanks for the help.
SickBoy 66, Small block chevys have a stock deck height of 9.025 that puts the piston down the hole .025 if everthing is perfect from the factory. I have found they are usually about .022 So IF your block IS NOT zero decked (meaning the extra .020 -.025 has not been machined off the deck surface to make the piston flush with the deck surface) using these parameters <CODE>Cylinder head Volume (CC) = 64.00</CODE> <CODE>Piston Top Volume (CC) = 4.00</CODE> (flat top w/Valve reliefs) <CODE>Cylinder Bore (Inches) = 4.0</CODE> <CODE>Cylinder Stroke (Inches) = 3.25</CODE> <CODE>Deck Height (Inches) = 0.020</CODE> <CODE>Head Gasket Thickness (Inches) = 0.039</CODE> ( Fel Pro 1003 gasket) you should be about 9.3/1 compression. "flat-top pistons with a 461 head, 64 cc chamber, gives 10;5 compression ratio" is true when using these parameters <CODE>Cylinder head Volume (CC) = 64.00</CODE> <CODE>Piston Top Volume (CC) = 0.00</CODE>* <CODE>Cylinder Bore (Inches) = 4.0</CODE> <CODE>Cylinder Stroke (Inches) = 3.25</CODE> <CODE>Deck Height (Inches) = 0.000*</CODE> <CODE>Head Gasket Thickness (Inches) = 0.030 </CODE> <CODE></CODE> <CODE></CODE><CODE>which is probably how Chevy caculated this to come up with that number the problem is they are not at Zero deck height from the factory and they dont count the valve reliefs either which usually add about 3-5 cc's to chamber volume</CODE> <CODE>when you pull your heads off measure how far down the hole the flat part of the piston is. If you find its.020 or more and there are valve reliefs in the top of the pistons you will be close to the 9.3/1 if its flush you can use a thicker gasket as mentioned above either way it can be done. </CODE> <CODE></CODE> <CODE></CODE>
I think you will be ok being its not decked and using the Felpro gasket mine is the same not decked and felpro gasket I have a few mor CC's of volume from heads being tinkered with and my pistons I think probaly a couple more CC's than stock pistons.
Just my two cents on the weight, I've got a '28 Sedan Delivery, V-6, auto, with me in it, (an old fat guy) the car's at 3020 lbs. Also the latest car I built, a "traditional" style modified: we built the very basic frame, very light -fragile- parts, V-8, 3 speed manual, T body, we figured at about 1300 lbs, but when we put it on the sprint car scales, it totaled 1845 lbs!!!! Except for the motor, we had picked up every individual part and couldn't believe how much it weighted when it was completed. K.
Im runnin a 327 in my 56 straight axle car,its got a 283 crank and a mild cam,,,,,,runnin a old streetmaster eldelbrock intake with a 600 eldelbrock carb,,,,,,I love it
Listen Tin Foil valves are great if your run out of the aluminum You can have my extra set for free! Cheers <input id="gwProxy" type="hidden"><!--Session data--><input onclick="jsCall();" id="jsProxy" type="hidden">
the m20 ******s have the best gear ratios in my opinion. 2,56 first i believe 1.94 2nd. m22s and 21s have lower gears 2.20 it also depends if you want a close or wide ratio. the wide ratio will help your car with gaining momentum. close ratios are fun but really for road racing or just trying to keep your car in a narrow power band, thus why they were mainly road race trannies. A 331 combo would be nice make good power for a light car. 461 heads are decent. with horse goota focus on heads and cam but for nostalgia cannt go wrong with old double humps on a 327.the runners are what kill its power though close to 160ish cc intake side. most likely around 350ish hp. depends on duration in the cam not the lift as much.
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