[mx671]

I'd like to know from someone who has actually tune nitrous with a set of yates heads. How much timing should we pull as a start, with 30 jets on a fogger E3 nozzle. We have the timing @ 26 initial. We've had several bad nitrous back fires through the carb.
The motor is a 9.2 deck 427, 14.1 comp. using VP n2o fuel, NGK 10 plug. This damn thing is sensitive on the tune. The last back fire nearly blew the hood off. Thanks for the help!

 

[Sam Vincent]

I'd like to know from someone who has actually tune nitrous with a set of yates heads. How much timing should we pull as a start, with 30 jets on a fogger E3 nozzle. We have the timing @ 26 initial. We've had several bad nitrous back fires through the carb.
The motor is a 9.2 deck 427, 14.1 comp. using VP n2o fuel, NGK 10 plug. This damn thing is sensitive on the tune. The last back fire nearly blew the hood off. Thanks for the help!

should be able to run anywhere from 16* to near 20* with a 30jet. if itsreal sensitive, might have to tight a quench

 

[moneypit]

Can you run a thicker gasket ? I went from .040 to .072 and tuneup is a lot happier. Whats the fp set on ? Have you verified the retard drop ?

 

[mx671]

Thanks for reply! They are 42cc chamber off a nacar truck. We are using a 1200 SVI carb. What can be done about the quench?

 

[SSOCOBRA]

If you arent familiar with the C3 I would recommend to back that nitrous jet off some and regroup..

 

[SSOCOBRA]

Thanks for reply! They are 42cc chamber off a nacar truck. We are using a 1200 SVI carb. What can be done about the quench?

Thicker gasket or soften the chamber..

 

[mx671]

Can you run a thicker gasket ? I went from .040 to .072 and tuneup is a lot happier. Whats the fp set on ? Have you verified the retard drop ?

The piston have a dish & he used the thickest copper gasket,to try'n get the comp down. Did you change plugs every pass, that seems to be some of the issue to me?

 

[Sam Vincent]

what is " the thickest copper gasket" how thick is that? is engine 0 decked, or piston + or - the deck?

 

[mx671]

If you arent familiar with the C3 I would recommend to back that nitrous jet off some and regroup..

I agree with you on this one, I'm trying to help a friend with his car. This thing is not nitrous friendly. It's been kicking our ass!

 

[mx671]

what is " the thickest copper gasket" how thick is that? is engine 0 decked, or piston + or - the deck?

Sam I will find out tomorrow when I speck with him. Sorry for lack of info.

 

[Max rider]

That's why I went with the TFS R outlaw head. Those Yates heads are to much sugar for a dime.

 

[mx671]

fuel pressure is @ 6lbs.

 

[SSOCOBRA]

At 42cc you will need to be alittle more careful.. @ 6psi (not knowing the jet spread) I would assume a .030 is prolly rich..

I would back up and make sure the engine is clean on the carb before applying nitrous.. I would say if you are changing plugs that soon you arent far from lifting ring lands...

 

[ernie's 5oh]

Yeah with the 14:1 comperession and a fast burn cumbution chamber, you might want to drop the CR down a bit, and look into the quench.

 

[SouthernTrendKill]

Might want to start with a smaller tune and see what it likes. Then work your way up. Jets are cheaper than pistons.

 

[bykr]

What is considered safe for quench ? I think I read on here around .030,is that about right?

 

[Sam Vincent]

What is considered safe for quench ? I think I read on here around .030,is that about right?

way too tight.

 

[Sick88lx]

What is considered safe for quench ? I think I read on here around .030,is that about right?

Maybe for a N/A motor but for nitrous it's different. I've heard minimum of .060 or so and I know my buddy's is about .070.

 

[SSOCOBRA]

What is considered safe for quench ? I think I read on here around .030,is that about right?

.030 isnt enough.. Mine is @ .065 and seems to work ok..

 

[bykr]

Is the problem with being too tight the piston expanding more on nitrous reducing the clearance to the head or a combustion issue?