BBC 2618 Icon Piston .008 piston to wall
Moderator: Team
BBC 2618 Icon Piston .008 piston to wall
Has anyone ever run an Icon 2618 BBC piston in a street engine with .007 to .008 piston to wall clearance? I believe the pistons rock in the bore about .025 too. Top ring gap is about .021.
Icon recommends PtW .0045-.0055 for street NA.
Will the engine beat itself up or just be a little noisy until it warms up?
492 BBC with 10:1 compression
Thanks
Icon recommends PtW .0045-.0055 for street NA.
Will the engine beat itself up or just be a little noisy until it warms up?
492 BBC with 10:1 compression
Thanks
Eric
Re: BBC 2618 Icon Piston .008 piston to wall
The shorter the piston, the bigger the problem will be with excessive bore clearance...
Re: BBC 2618 Icon Piston .008 piston to wall
Been several discussions here recently about using custom coatings to take up the slop.
Jack Vines
Studebaker-Packard V8 Limited
Obsolete Engineering
Studebaker-Packard V8 Limited
Obsolete Engineering
Re: BBC 2618 Icon Piston .008 piston to wall
Thank you for your replies. I will check into coatings.
Eric
-
- Guru
- Posts: 4585
- Joined: Sun Sep 18, 2011 11:31 am
- Location: Heading for a bang up with Andromeda as we all are.
Re: BBC 2618 Icon Piston .008 piston to wall
You had better run a Barrel face second ring if your having less then pefect PTB issues , as all the coatings in the world will not help the rings seal better!
You can cut a man's tongue from his mouth, but that does not mean he’s a liar, it just shows that you fear the truth he might speak about you!
Re: BBC 2618 Icon Piston .008 piston to wall
Line2Line claims their coating will fill up the sloppy clearance between the piston and bore. Sounds like magic to me. I wonder if anyone has successfully done this on Speedtalk. From Line2Line's website:
ADVANTAGES:
Restores and Holds Clearances
Highly Wear Resistant
NHRA Pro-Mod Tested
AND
Piston Skirt Coating reduces operational clearances, protects piston skirts from scuffing, retains oil, and reduces friction. Recommended when piston and bore dimensions are providing stock clearances. Reduces slap and ring flutter compared to uncoated pistons, effectively improving ring seal and reducing wear on the pistons and rings. Also protects the interface from foreign particle wear. During a short break-in cycle (5-15 min), excess coating thickness will wear away where contact stresses are highest. Where there is room, lower contact stresses allow the thickness to remain and reduce operating clearances.
ADVANTAGES:
Reduces Stock Clearance for Best Fit
Reduces Slap for Better Ring Seal
Protects Against Scuffing
Retains Oil Film
Promotes Hydrodynamic Sliding
Reduces Friction
2 Strokes Run Quieter Crisper
ADVANTAGES:
Restores and Holds Clearances
Highly Wear Resistant
NHRA Pro-Mod Tested
AND
Piston Skirt Coating reduces operational clearances, protects piston skirts from scuffing, retains oil, and reduces friction. Recommended when piston and bore dimensions are providing stock clearances. Reduces slap and ring flutter compared to uncoated pistons, effectively improving ring seal and reducing wear on the pistons and rings. Also protects the interface from foreign particle wear. During a short break-in cycle (5-15 min), excess coating thickness will wear away where contact stresses are highest. Where there is room, lower contact stresses allow the thickness to remain and reduce operating clearances.
ADVANTAGES:
Reduces Stock Clearance for Best Fit
Reduces Slap for Better Ring Seal
Protects Against Scuffing
Retains Oil Film
Promotes Hydrodynamic Sliding
Reduces Friction
2 Strokes Run Quieter Crisper
Eric
Re: BBC 2618 Icon Piston .008 piston to wall
Yes.Bishop540 wrote:I wonder if anyone has successfully done this on Speedtalk.
Re: BBC 2618 Icon Piston .008 piston to wall
Anyone else having difficulty translating this?Recommended when piston and bore dimensions are providing stock clearances.
Reduces Stock Clearance for Best Fit
Jack Vines
Studebaker-Packard V8 Limited
Obsolete Engineering
Studebaker-Packard V8 Limited
Obsolete Engineering
Re: BBC 2618 Icon Piston .008 piston to wall
I guess stock clearances are too loose for them and need to be tightened up.....PackardV8 wrote:Anyone else having difficulty translating this?Recommended when piston and bore dimensions are providing stock clearances.
Reduces Stock Clearance for Best Fit
Eric
Re: BBC 2618 Icon Piston .008 piston to wall
Yes, I think they are saying that stock clearances are designed to live long and prosper under worst case conditions, so coating them up to/near zero allows it to open up only where and how much required for your app. Under this scenario, the worst that could happen if a rare extreme arose would be self-clearance a tad more.
Felix, qui potuit rerum cognscere causas.
Happy is he who can discover the cause of things.
Happy is he who can discover the cause of things.
Re: BBC 2618 Icon Piston .008 piston to wall
Yes Sir, I think it is my best option at this point.MadBill wrote:Yes, I think they are saying that stock clearances are designed to live long and prosper under worst case conditions, so coating them up to/near zero allows it to open up only where and how much required for your app. Under this scenario, the worst that could happen if a rare extreme arose would be self-clearance a tad more.
Eric
Re: BBC 2618 Icon Piston .008 piston to wall
Pistons off to Line2Line. They said they will coat them to .002 PtW, and then let the 2618 do its magic for the rest of the clearance needed. I hope this is a big step in the right direction.
(gonna start another thread about bearing clearance)....
(gonna start another thread about bearing clearance)....
Eric
-
- Guru
- Posts: 1649
- Joined: Tue Mar 06, 2007 7:23 pm
- Location: San Tan Valley, AZ
- Contact:
Re: BBC 2618 Icon Piston .008 piston to wall
Just for future reference, at .008, the thing would sound like a diesel at idle. Temperature wouldn't have mattered. It wouldn't kill the motor, it would just be noisy.
We once did a 283 Chevy at .006 and it was still noisy, but fine. We did a Chrysler "A" motor at .004. It ran great, but don't stop at the donut shop unless you have time to lose the heat soak, because it wasn't going to start until it was cold.
This was back in the day when we were still grinding pistons. The skirt designs we use now can still be run at or above .008, but they're not optimum.
We once did a 283 Chevy at .006 and it was still noisy, but fine. We did a Chrysler "A" motor at .004. It ran great, but don't stop at the donut shop unless you have time to lose the heat soak, because it wasn't going to start until it was cold.
This was back in the day when we were still grinding pistons. The skirt designs we use now can still be run at or above .008, but they're not optimum.
-
- Guru
- Posts: 8687
- Joined: Sun Jan 21, 2007 1:16 pm
- Location: Victoria BC Canada
Re: BBC 2618 Icon Piston .008 piston to wall
I have to ask why??
The piston is inexpensive to start with so I got to ask why would you not just go to the next oversize??
The piston is inexpensive to start with so I got to ask why would you not just go to the next oversize??
Real Race Cars Don't Have Doors
Re: BBC 2618 Icon Piston .008 piston to wall
They may be "inexpensive" in Canada but not in the USA.ProPower engines wrote:I have to ask why??
The piston is inexpensive to start with so I got to ask why would you not just go to the next oversize??
Eric