Compression ratio for bracket racer

[RichardThiessen]

High compression and big cams hide deficiencies.... little surprised they went to the extreme of 16.5:1 though... especially if they did it on purpose. Maybe 14.5:1.

[MPac]

If the pistons where hitting the heads like you said that would make me want to look through the valve train also cause I would think vavles where probably hitting too. I am by no means an expert like you Joe. It's just a thought.

[D.S.R.E.]

16.5? wow! Did you measure the Cranking compression by chance? Thats Wayyy too advanced!

[raynorshine]

After 13.5/1 gains get smaller and the problems become bigger.

I have wondered how much is left behind with the alcohol crowd wanting and running in the 15:1 area with 355 and 23 heads with that big dome/dam in the way.

me too, wish i said that

[Bucky]

I wonder if they stuck that cam in there advanced because they were having some p to v issues. Obviously the dome needs to come down or be reshaped to not hit the head, but maybe a flycut would be in order also tomake sure there is plenty of room for different cams put in at different positions. Just a thought.

I am currently running a tad over 14:1 on alky, and the engine seems to like it. I ran a tad over 13:1 for years on alky, and all was fine. I do think some of my gains when I updated my combo are from the extra compression. It may seem obvious, but when you talk alky and compression ratio, you can't overlook the cam. A big cam will of course in general like a bit more compression to work ideally. I don't think there is any right or wrong answer for compression ratio with alky. I have seen 12:1 and 15:1 work well.

[Keith Morganstein]

I think very high compression is overrated. Something a bit over 13:1 is fine for racing gas engines and little less than that with a crappy chamber.

[Mark O'Neal]

10:1 is fine for a bracket racer. He's running a number.

[lun40119]

Keep us posted on the results after you fix it Joe. I bet you'll wake her up!

Of course he will..........Duh!!! Why do you think he started a thread.

Joe.........bracket motor........Id go pump gas..........like Mark said, he is only running a number.

[revolutionary]

He could always run it at Denver...

[john@bmp]

Something seems wrong....700 Seems awfully light for that engine. Joe, when you get it all fixed up let us know what it is, so we can file that away in the crevices of my eroding brain.

[sjvalleydave]

We are a tad under 15:1 on race gas, but since we are doing this with flat top pistons we aren't really leaving anything out there, you think?

[Bucky]

We don't build race engines to just run the number. Racers like to go fast too!

[af2]

You think he might be running an INDEX ##?

[rustbucket79]

10:1 is fine for a bracket racer. He's running a number.

With that theory it's a wonder why there aren't more of us running Pontiac Fireflys.

When I started bracket racing in 1991, there were a pile of us running 14's, and it was fun. Those of us still racing today that raced back then, are running the same cars, with different powerplants. The bulk of us are running 10's, with some of us knocking on the 9 second door. Most of us are running race gas, the rest are running premium with a Snow system. I gladly pay the money for VP 113, it's peanuts compared to the cost of everything else associated with racing, and I prefer to run quicker rather than slower.

[MELWAY]

10:1 is fine for a bracket racer. He's running a number.

With that theory it's a wonder why there aren't more of us running Pontiac Fireflys.

When I started bracket racing in 1991, there were a pile of us running 14's, and it was fun. Those of us still racing today that raced back then, are running the same cars, with different powerplants. The bulk of us are running 10's, with some of us knocking on the 9 second door. Most of us are running race gas, the rest are running premium with a Snow system. I gladly pay the money for VP 113, it's peanuts compared to the cost of everything else associated with racing, and I prefer to run quicker rather than slower.

HAHA might be peanuts for you guys,,,,,we pay 220-250 dollars for 5gallons of Q16