Drilled slides to large - will they be OK?

[Krunk_Kracker]

OK - I got my Dynojet kit installed and by an extreme stroke of stupidity, I drilled the slides with the 5/32" drill bit.

I've contacted Dynajet through email and they are telling me that it should still run fine, but that it *may* stumble at the beginning of a rev and when rolling on the throttle. I haven't yet been able to test this due to a bad petcock.

Has anyone had experience with this? Is there anything I can do with the needle to compensate for this?

The rep with Dynojet said that I can use some sort of two part epoxy and fill the hole and redrill it directly beside it.

Thoughts?

[Guest]

I'd try to run it and see what happens.
If you dont wanna do that or it happens to not run correctly you can full the holes with JB weld and drill em with the correct bit.

[Krunk_Kracker]

I'd try to run it and see what happens.
If you dont wanna do that or it happens to not run correctly you can full the holes with JB weld and drill em with the correct bit.

Should I drill through the JB Weld or move directly beside it?

[Guest]

The one I did, I drilled right through the JB weld.

[Krunk_Kracker]

The one I did, I drilled right through the JB weld.

Awesome, thank you very much!


How much JB weld did you use? Did you fill the entire hole?

[TheCafeKid]

Awesome, thank you very much!


How much JB weld did you use? Did you fill the entire hole?

Fill the hole. Let it set. Start over. It'll be just fine

[chuck hahn]

Since i am not a engine builder..plz enlighten me as to what drilling a sslide is and what its supposed to do.

[Steve]

Since i am not a engine builder..plz enlighten me as to what drilling a sslide is and what its supposed to do.

In the CV carbs, there is a hole in the bottom of the slide that transfers the vacuum up to the space above the diaphragm to pull the slide up. When you install a jet kit (usually due to pods and a header), the engine can handle more air quicker, but the holes are not big enough to transfer the vacuum quickly enough. Drilling them out a bit will help quicken the response. Drilling the hole too large will tend to lift them too quickly, making the carbs stumble because the velocity of the air flow is lost because the slides lifted.

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[Mith]

I must have been thinking about this backwards. I thought the hole was to allow the slide to drop more quickly when you let off on the throttle. Is there a diagram or powerpoint that explains how these carbs work at different throttle positions? They are a bit confusing.

[Krunk_Kracker]

The CV slide regulates how where the needle is in reference to where you are in the throttle.

Here's a diagram:

[Mith]

I see it more clearly thanks to your picture. Increasing the hole size must make the slide more responsive in both the time it take to raise as well as lower the slide based on the vacuum created on the intake stroke, correct? I think I was seeing only half of the picture.

[Krunk_Kracker]

I see it more clearly thanks to your picture. Increasing the hole size must make the slide more responsive in both the time it take to raise as well as lower the slide based on the vacuum created on the intake stroke, correct? I think I was seeing only half of the picture.

Yes, exactly.

I haven't tested it yet, I'll report back to this thread how the larger holes act.

[Steve]

I thought the hole was to allow the slide to drop more quickly when you let off on the throttle.

Technically speaking, it wouldn't really matter how long the slides stay up when you close the throttle.

The butterfly is what is connected to the cable, and is what controls the output to the cylinders. The slide only modulates the velocity of the airflow across the jets in the carb throat. When you close the butterflies by letting off the throttle, there is NO air flow, so it does not matter where the slides are, as there is no demand.

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[Billy Ricks]

The CV slide regulates how where the needle is in reference to where you are in the throttle.

Here's a diagram:

That's an RS flatslide, completely different animal. The DJ kits used to include new return springs for the slides, not sure if they still do or not. The new springs and drilled slides are meant to give you quicker throttle response.

[Guest]

No springs just drilling the slides on the new DJ kits. I believe the Factory Pro kits still include the spring.

I have JB Welded some slides back to stock and they were just fine. Drill through the center just like you did with the wrong bit.