carb spacer question

[rubbinsracin]

ok guys we run a gauge legal 4412 on top of our 11-1 383 and we were wondering something. we have a victor JR intake with an adapter that provides the regular 1 1/2" we are normally allowed to run.

what would happen if we were able to add an additional open carb spacer that would open it up say either a 1" or 2" spacer (we have both)?

[cassellracing24]

There is so much velocity threw a 350\500 carb @ rpm that getting the carb as high away from intake runner floor is critical to performance. You want the air to go threw the carb and make a gradual change in direction so fuel stays suspended in air. If air hits the floor of intake, fuel suspention is lost as well as power\efficiency.

[rubbinsracin]

so if i were to put a 2" spacer under the carb adapter i would have better performance?

[sj valley dave]

The old rule of thumb is that when you get the carb further away from the cylinder the engine will gain top end HP and lose a little on the bottom end...Think of a tunnel ram scenario...

[rubbinsracin]

so it might be beneficial to have the spacer on a 4412 steelhead motor against say a 602 or 604 with a 4bbl? i give up most of my speed on the end of the straights.

[stock car driver]

If you give up speed at end of straights I would go one less gear, unless youve gotta have that gear to get off the corner with the crate? In which case losing bottom end from the spacer may hurt more than it helps.

[bushracing67]

The old rule of thumb is that when you get the carb further away from the cylinder the engine will gain top end HP and lose a little on the bottom end...Think of a tunnel ram scenario...

car craft busted that myth years ago, a tunnel ram makes more power top to bottom, the ratio to low end to high end changes, but it all goes up compared to the single 4bbl

[rubbinsracin]

If you give up speed at end of straights I would go one less gear, unless youve gotta have that gear to get off the corner with the crate? In which case losing bottom end from the spacer may hurt more than it helps.

Sorry stock car, guess i wasnt very clear. we run an 11-1 spec motor with a 4412 against 602 and 604 motors that are allowed to run any 4bbl they want. so im ok off the corners until their secondaries really kick in and i loose about a 1/3 to 1/2 a car length going down the straights. doesnt seem like much i know...but alot of the racers around here, a half car is all they need to slam the door. we are already in the RPM range we want to be at, so we were looking to see if adding a spacer under the carb would give us a little extra boost at the end of the straights.

[stock car driver]

Sorry stock car, guess i wasnt very clear. we run an 11-1 spec motor with a 4412 against 602 and 604 motors that are allowed to run any 4bbl they want. so im ok off the corners until their secondaries really kick in and i loose about a 1/3 to 1/2 a car length going down the straights. doesnt seem like much i know...but alot of the racers around here, a half car is all they need to slam the door. we are already in the RPM range we want to be at, so we were looking to see if adding a spacer under the carb would give us a little extra boost at the end of the straights.

No it wont help the spacer doesnt add power it moves the power curve up higher in the rpm range.

If your losing ground mid straight a spacer or gear change may give you more power there, BUT you will lose power in the corner now and that may put u behind them already.

[rubbinsracin]

so what you're telling me is i need more motor, or a crate lol.

[stock car driver]

I dont know. If your only getting pulled at the end of the straight, you might just need to gear differently.

[rubbinsracin]

do you think if i went down like 15ish points it would be enough. say from a 6.29 to a 6.13?

[stock car driver]

that is clearly the first thing i would try

[parrot69777]

If you are getting beat...and everything is good out of the corner....sounds like you need a cam change.

[sj valley dave]

Bushracing67, You misunderstood what I was trying to say...Yes a good tunnel ram will make more power everywhere, but it moves the curve up in the RPM range. Just like Stock Car Racing stated, you might only get a small bump in HP numbers, but it will move the power curve up the RPM range...