Starting spot for jets...

[Icetech]

Just curous if anyone has an opinion on where i should start with jets.. Just bought a new carb and it's a bit large for my current motor (bought it for the next motor but want to use it for now) Which will be a 408..

850 with annular boosters..
Current motor is a 318 with trick flows and a howards roller 232@.50

Carb came with 78/86 which is gonna be way too big.. Was thinking 68/76?

will tune with a AFR gauge when i get it installed.. just wanna start in the right area.. And time to blow $100 on a jet kit..

 

[RustyRatRod]

I think you need a smaller carburetor.

 

[Icetech]

I think you need a smaller carburetor.

for a 408? 850 should be fine... with the annular boosters it will actually be around 820...

 

[RustyRatRod]

for a 408? 850 should be fine... with the annular boosters it will actually be around 820...

Where did it say 408? I see 318 as the only engine size.

 

[Icetech]

Where did it say 408? I see 318 as the only engine size.

you are right.. i just put that it's for my next motor without saying the size.. i am pure fail.

 

[RustyRatRod]

you are right.. i just put that it's for my next motor without saying the size.. i am pure fail.

Well no, I ain't a mind reader, either. lol

 

[Cuda416]

Just curous if anyone has an opinion on where i should start with jets.. Just bought a new carb and it's a bit large for my current motor (bought it for the next motor but want to use it for now)

850 with annular boosters..
Current motor is a 318 with trick flows and a howards roller 232@.50

Carb came with 78/86 which is gonna be way too big.. Was thinking 68/76?

will tune with a AFR gauge when i get it installed.. just wanna start in the right area.. And time to blow $100 on a jet kit..

Holly calibrates there stuff at sea level I think, then they have guidelines to where you go from there based on your altitude. Something like one bump for every 500 or 1000 feet. You'd need to look it up I'm afraid as I don't have it in front of me. Lot's of talk here in the past on using AFR gauges and how they can "lie" so look do some searching to find that. I agree with @RustyRatRod though, that's an awfully big carb for that engine. Maybe start with a 600 which will give you way better low speed velocity of the air fuel charge.

 

[Icetech]

Well no, I ain't a mind reader, either. lol

yeah.. i don't get why people don't understand what's in my head if i don't spell it all out.. come on people!

 

[TT5.9mag]

Put it on with the stock jetting. Tune from there. You have no idea how little or how big the signal will be from the 318. Jetting will be in direct proportion to throttle blade size AND signal. The 318 will not tug as hard on an 850 as it will on a 600 so the fuel orifice will have to be bigger. It might be difficult to get it to respond to tuning simply because it’s a lot of throttle valve area for a small cu/in but it will run.

 

[Icetech]

Put it on with the stock jetting. Tune from there. You have no idea how little or how big the signal will be from the 318. Jetting will be in direct proportion to throttle blade size AND signal. The 318 will not tug as hard on an 850 as it will on a 600 so the fuel orifice will have to be bigger. It might be difficult to get it to respond to tuning simply because it’s a lot of throttle valve area for a small cu/in but it will run.

thanks TT.. i figure the annular boosters will help with the smaller 318 signal.. it's only going to be a for a month or 2 anyway

 

[TT5.9mag]

thanks TT.. i figure the annular boosters will help with the smaller 318 signal.. it's only going to be a for a month or 2 anyway

Ive actually found the opposite to be true.

 

[Icetech]

Ive actually found the opposite to be true.

well pewp.. that's the opposite of everythign i read... it is what it is... will see how it goes...

 

[TT5.9mag]

well pewp.. that's the opposite of everythign i read... it is what it is... will see how it goes...

Don’t loose sleep over it. Put carb on, tune carb. Drive. It’s that easy.

 

[Bobzilla]

It's winter here Michigan. Are you planning to actually drive it with that carb on or just idle tuning in the garage? I enjoy tinkering, but may not be worth the effort unless you are going to take it out for a drive.

 

[Icetech]

It's winter here Michigan. Are you planning to actually drive it with that carb on or just idle tuning in the garage? I enjoy tinkering, but may not be worth the effort unless you are going to take it out for a drive.

I will drive a bit.. i like winter driving on days when there's no snow/salt... plus my heat works which is nice But mainly looking forward to spring and planning ahead

 

[Bobzilla]

Any update on your block, when machining will start? Probably any time now I would think. Looking forward to hearing about your experience with him.

 

[Icetech]

Any update on your block, when machining will start? Probably any time now I would think. Looking forward to hearing about your experience with him.

Not yet. i'm gonna text him later in the week.. starting to get to me..

 

[Icetech]

I was more worried about how long a stroker kit might take to get.. talked to hughes and they can have a 426 kit for me in a few days.. no idea on a 408..

All the hughes 408 kits now are made for Magnum blocks which is a different deck height.. don't want to wait another 5 months if i need the deck cut .020.. at that point i would probably just leave the pistons down and eat it..

 

[Bobzilla]

He'll be decking it to true it up anyway, won't he?

 

[Icetech]

He'll be decking it to true it up anyway, won't he?

yeah.. but i don't know what i will need to be zero deck until i get the stroker kit.. and i can't order a stroker kit til i know if i my block is even usable or what bore.. sooo.. tons of fun

 

[Bobzilla]

yeah.. but i don't know what i will need to be zero deck until i get the stroker kit.. and i can't order a stroker kit til i know if i my block is even usable or what bore.. sooo.. tons of fun

At least your block is at the shop, in line for the work. That is good. My junk is still sitting in the garage taking up space.

 

[Icetech]

At least your block is at the shop, in line for the work. That is good. My junk is still sitting in the garage taking up space.

Take it to automotive on groesbeck..

Home

www.automotivemachine.net

 

[Bobzilla]

Take it to automotive on groesbeck.. i wish i had gone there at this point.. Spring is coming fast..

http://[URL]https://www.automotivemachine.net/

[/URL]

Good things come to those who wait. Don’t worry so much. DVW says that guy is good. I would much rather wait longer from a really good small shop instead of rushing it through a high volume shop with lower standards. I am hoping you’ll be impressed with his work. We have a long winter ahead still.

 

[CRUZE 418]

My 418 doesn't seem to want much different jetting than the 340. It's a 6-pack, but the jetting is almost identical. Considerably smaller than what you are talking about. Would be interesting to see where you end up at.

 

[Icetech]

Good things come to those who wait. Don’t worry so much. DVW says that guy is good. I would much rather wait longer from a really good small shop instead of rushing it through a high volume shop with lower standards. I am hoping you’ll be impressed with his work. We have a long winter ahead still.

yeah. i'm just antsy and wanna get goin