Head Numbers

[probert]

The cylinder head numbers on my sbc are 3890462. Any charts I've seen say they are 2.02 valves with 64 cc chambers. I tried measuring the valves without removing them and they appear to be 1.94. Were both valve sizes available for these heads and if so are they indeed 64 cc chambers?
Thanks

[Charley Lillard]

On 202's the valves will almost be touching each other while 194's will have about 1/8" between them. Welcome to the site and please fill out your Profile.

[jg95z28]

According to Colvin, that head was available with both 2.02/1.60 and 1.94/1.50 valves. In 1966 they had 62.076 cc chambers in 1967 they increased to 63.305 cc.

[Zman]

I have 2 sets of 462s, both are 194s

[probert]

There's about 1/8" gap between the valves so it looks like they ARE 1.94's. This is a sweet running little engine and I originally just wanted to freshen up the bearings and rings. I'm pretty bummed to find out they aren't 2.02's....I'll be lucky if I'm getting 340 hp! Funny how the numbers can take the smile off your face :-(
Thanks for the help tho, appreciate it!

[JoeC]

some castings can be converted to 202 valves.
check with your machine shop

[Salvatore]

I wouldn't be bummed out if I were you. Until you saw the size of the valves you thought the engine ran real nice! It is almost impossible to feel the difference on the street with the bigger valves. Remember all 350cu. 300hp cars have the small valves, also all the 275hp-327 cars do too. Some of those low H.P. cars are running in the high tens,low 11's in Stock Eliminator. SO.....Be Happy! Sam

[Supergas990]

My 67 Chevelle has the 275hp 327 in it with those heads on it. You'd be suprised how quick that thing winds up and takes of.

Remember... BIGGER isn't always better!!! It's all in the combination.

Blair

[probert]

I bought the car a couple of years ago, a 69 Firebird, not so much for the engine but the owner told me not to scrap it.Despite it's looks he assured me it was a strong runner, just needed some work.I tinkered with it, got it running and damned if he wasn't right, it's quick.I just recently tore it down and here's what it's got.It's a 355 with flat top pistons, a single plane Edelbrock intake, 600 Holley and a Comp Cams 274H cam.Behind it is a Saginaw 4 speed and a 355 rearend.
You guys are right, bigger isn't always better and the cam that I took forever to select has set off the combination nicely....300- 340 hp?? but I can't help wonder how many horses those 2.02's would add

[Salvatore]

Hey Probert, Is the motor a chevy or a pontiac? Also the Saginaw is probably a 3.00 first gear. A lot of torque especially is it is a Pontiac motor. sam