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In 1962, Chevy came out with the double hump heads with 1.94/1.50 valves. Then in 64, they increased the valve size to 2.020/1.600.
Can anyone tell me how to tell the difference between the two without pulling the heads? Are the humps shapped differently?
Thanks for any help
Chevy continued to use 1.94 heads on many mid level engines, even after the lager valves were added on the high horsepower options. In the late '60s they would have tapped holes in the ends of the heads. I don't remember any way to tell from the outside, and I suspect they used the same castings for both valve sizes.
I built some really good running engines with the 1.94 heads, and I doubt you would see much improvement, unless you were building a radical motor.
As a side note, I think the biggest difference was actually in the exhaust valves.
I agree with Hotrod. Everyone wants 2.02s, but the reality is they're not that much better. Plus, I understand that many of the 2.02s out there were just opened up 1.94s and the intake valves were never unshrouded.
When people talk about un-shrouding a valve that refers to work done to the combustion chamber not in the seat or bowl area.Quote:
Originally posted by MI2600
I agree with Hotrod. Everyone wants 2.02s, but the reality is they're not that much better. Plus, I understand that many of the 2.02s out there were just opened up 1.94s and the intake valves were never unshrouded.
If you had a 2.02 valve with a 450 lift on the cam could'nt you get as much flow using a 1.94 valve with a bigger lift like 500 or so? Guess you could figure it with the correct formulas.
a head with bigger port's/ valves will not flow as good as a smaller 1 at street RPM's, so in a lot of cases actully, smaller is betterQuote:
Originally posted by chevydrivin
If you had a 2.02 valve with a 450 lift on the cam could'nt you get as much flow using a 1.94 valve with a bigger lift like 500 or so? Guess you could figure it with the correct formulas.
Matt167,you are right about one thing.Sometimes smaller is better for most aftermarket cylinder this holds true.In other words you can't put a 200 cc head on a 350 with a cam that is done at 5,500 r.p.m.s. Most performance SBC can use more cylinder head than a stock head.Quote:
Originally posted by Matt167
a head with bigger port's/ valves will not flow as good as a smaller 1 at street RPM's, so in a lot of cases actully, smaller is better
It's possible the casting number could point you to a certain vehicle application which may give you a ballpark idea. But specifically, no.
Camel hump heads came with a variety of combustion chamber sizes and I don't know that all of the larger chambered ones had 2.02"s. I would also suggest that the intake/exhaust port volume was larger in a number of models .
I have heard it said that care should be taken when enlarging for a bigger valve spring on the end that is near the water passage.
The problem is the double hump heads are 40 yrs. old and by the time you put a few seats in them,surface them and replace the guides and do a valve job,put in screw-in studs,enlarge the spring pockets and what you still have is a set of 40 year old heads that don't flow as well as the new ones and are prone to cracks.Quote:
Originally posted by 4dr 57
It's possible the casting number could point you to a certain vehicle application which may give you a ballpark idea. But specifically, no.
Camel hump heads came with a variety of combustion chamber sizes and I don't know that all of the larger chambered ones had 2.02"s. I would also suggest that the intake/exhaust port volume was larger in a number of models .
I have heard it said that care should be taken when enlarging for a bigger valve spring on the end that is near the water passage.
2.02 and 1.60 valves are great for saving worn out 1.94 and 1.50 heads. Other than that, I've never seen any difference in power on a street engine.
hi guys you're right in just about eveything you're saying about the 2.02 heads, if memory serves me right mine are #462 castings
i've had mine rebuilt,stainless inserts to handle unleaded fuel,ported polished,etc etc...long story short 1000 bucks(can)
i was bolting them back on. for about the same price aftermarket is the way to go and lots lighter too!