Hot Rods 1954 331 combustion chamber size

Hello and thanks for the add.

Question; what is the combustion volume of a stock 1954 331 Chrysler Hemi head # 1486833 ?

thanks,
Hank

 

Not sure. The best bet would be to measure.

If they are anything like later 354 chambers, they vary. I always spend a little time equalizing them. Not totally necessary, but it makes me feel better.

 

I'm thinking around 100cc.
What are you aiming for?

 

The 392's that I had were 105cc if my memory hasn't failed me. There were usually decked and ended up slightly less than 100cc. The 354 has a 1/16 smaller bore but the racers used to swap heads alot. What I don't know is if they had different domes cut for the pistons. On a fuel motor that had a 180 down piston, it wouldn't have made any difference. This info is only a starting point for you. Sorry I don't have better info.

 

I need to order custom pistons and the order sheet asks for that information but honestly I can’t find it nor do I know how to measure it. Can you help?

 

I had 55-331 heads, that were 109 cc, 392's were 117, as I remember.

 

Where are you located?

There are members spread across the globe. Someone might be nearby that can measure them.

Either that or a good race car shop.

 

You need a burette and some perspex/lexan etc. sheet.
Look up cc'ing combustion chambers on youtube, I'll bet there are plenty of how to's.

 

Here's a video:

 

The last set of 354 heads that I did were 110-111cc after cleanup.

I won't chase the last cc. It is too easy to go too far, and it is not worth it.

 

My '53 331 Chrysler heads came in around 98cc.

 

Here is a 331 triple nickel head. This particular chamber was rite at 100cc. I did a industrial 354 next and it was 105.

 

If you are desiring anything above 9-1, you will need the deck height of the block and the depth of the chamber. Because hemi's have such a tall piston, every measurement is very important. You need to know what a piston designer knows to get it right. It is possible with custom maker to order 1 piston and see how it fits and then order the rest to match. That's a little pricey to do that. Very few people get it right the 1st time. If you are unfamiliar with all of this, I would see if there is a video that someone is measuring an early hemi to reference from.

 

This is why I mentioned that they vary, and that measurement is critical. I have seen the same casting number, with the same valve cover to deck measurement, come up with a different cc measurement.

Given the bore and stroke of the early Hemi, 10cc is about one-point in static compression ratio change.

Hemis are generally more tolerant of a slightly higher compression ratio than a wedge-chamber engine, due to the chamber shape, but there are limits to what pump gas can do.

Ross has been making the pistons that I use in Hemis. I have never had an issue with their work. First try, every time.

 

That’s who I plan on using is Ross.

 

Their form is comprehensive, and they know what they are doing.

Measure, or have measured all eight chambers.

Give them the smallest number if they differ.

 

A lot depends on the c/r you are wanting and how much leeway you build in. If you cannot measure the chambers then its a crap shoot. Although the heads should be around 105 it is never a given unless you know for a fact that the heads have never been cut. If you cannot measure them then error on the safe side and use 108cc or 110cc.