ICON 9929 Piston Specs
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ICON 9929 Piston Specs
It seems I've finally zeroed in on the build direction. Met with my machinist today. I'll be rebuilding the old lump and moving to a 40 over 350 (Gen 1 SBC).
He's suggested the ICON 9929 forged piston from their FHR series.
What I'm finding is conflicting information regarding the compression height.
I've fired off an inquiry to ICON for clarification as well as the weight specs. In the meantime I thought I'd throw out the clarification question here at ST.
The newest info I've found from ICON online lists the compression height at 1.550.
Older ICON catalogs and Summit both list the height at 1.560". There's also a discrepancy regarding the valve relief volume. 3.7cc vs 5 cc.
Does anyone have any recent experiences with this piston?
Recent catalog.
Older catalog.
Summit.
The engine had Speed Pro H631P pistons with a 1.560" height. That makes for a .014" below deck piston combined with a .026" gasket for a .040" PTH clearance.
The newer spec piston will result in a .024" piston below deck. That impacts a lot of things.
He's suggested the ICON 9929 forged piston from their FHR series.
What I'm finding is conflicting information regarding the compression height.
I've fired off an inquiry to ICON for clarification as well as the weight specs. In the meantime I thought I'd throw out the clarification question here at ST.
The newest info I've found from ICON online lists the compression height at 1.550.
Older ICON catalogs and Summit both list the height at 1.560". There's also a discrepancy regarding the valve relief volume. 3.7cc vs 5 cc.
Does anyone have any recent experiences with this piston?
Recent catalog.
Older catalog.
Summit.
The engine had Speed Pro H631P pistons with a 1.560" height. That makes for a .014" below deck piston combined with a .026" gasket for a .040" PTH clearance.
The newer spec piston will result in a .024" piston below deck. That impacts a lot of things.
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Kevin
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Re: ICON 9929 Piston Specs
Kevin,
Do they offer a thinner ring pack?
Do they offer a thinner ring pack?
steve c
"Pretty don't make power"
"Pretty don't make power"
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Re: ICON 9929 Piston Specs
i don't know what your Combustion Chamber CC's are ?
i used 58cc and 64cc
they list the Flat-Top Piston's Valve Notches as plus + CC Volume ??
it should be negative CC volume .
i used 58cc and 64cc
they list the Flat-Top Piston's Valve Notches as plus + CC Volume ??
it should be negative CC volume .
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Re: ICON 9929 Piston Specs
I'd looked into that Steve. The thinner ring pack I was looking for is an option but it looks to be only with a 6" rod version of that same piston.
Kevin
Re: ICON 9929 Piston Specs
I'll get all of my build data together and post it up.maxracesoftware wrote: ↑Sun Jan 16, 2022 12:26 am i don't know what your Combustion Chamber CC's are ?
i used 58cc and 64cc
they list the Flat-Top Piston's Valve Notches as plus + CC Volume ??
it should be negative CC volume .
SkinnyZ_CompRatios.jpg
Kevin
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Re: ICON 9929 Piston Specs
skinny z wrote: ↑Sun Jan 16, 2022 12:37 amI'll get all of my build data together and post it up.maxracesoftware wrote: ↑Sun Jan 16, 2022 12:26 am i don't know what your Combustion Chamber CC's are ?
i used 58cc and 64cc
they list the Flat-Top Piston's Valve Notches as plus + CC Volume ??
it should be negative CC volume .
SkinnyZ_CompRatios.jpg
You do not have the required permissions to view the files attached to this post.
Re: ICON 9929 Piston Specs
The latest web pdf catalog I downloaded list the 9929 as 1.55" CH
My older 2008 catalog pdf says 1.565".
The KB hyper flat top is listed as 1.56" KB120.
Does this build really need re boring and new pistons?
My older 2008 catalog pdf says 1.565".
The KB hyper flat top is listed as 1.56" KB120.
Does this build really need re boring and new pistons?
Re: ICON 9929 Piston Specs
If all you can get is a 1/16-1/16-3/16 ring pack I’d look for a different piston. There is no reason to run those big, heavy, clunky ring packs. I’d spend more money on pistons and rings and skip the 4 corner cooling. Rings reduce friction and save power. The 4 corner cooling is a fool’s errand.
Re: ICON 9929 Piston Specs
Last build:maxracesoftware wrote: ↑Sun Jan 16, 2022 12:43 amSkinnyZ_CH.jpgskinny z wrote: ↑Sun Jan 16, 2022 12:37 amI'll get all of my build data together and post it up.maxracesoftware wrote: ↑Sun Jan 16, 2022 12:26 am i don't know what your Combustion Chamber CC's are ?
i used 58cc and 64cc
they list the Flat-Top Piston's Valve Notches as plus + CC Volume ??
it should be negative CC volume .
SkinnyZ_CompRatios.jpg
Speed Pro 4.030" flat top piston with 5 cc valve relief.
Measured piston below deck at .014" with a 1.560" compression height piston.
Victor Reinz/Mahle head gasket. .026" x 4.125".
.040" PTH clearance.
Measured 65.4 cc combustion chamber
10.2:1
___________________________________
If using the old ICON piston spec and no additional machining other than the overbore:
ICON 4.040" flat top piston with 3.7 cc valve relief. 1.560" compression height.
Piston would maintain the .014" below deck measurement.
Same head gasket (.026" x 4.125").
.040" PTH clearance.
Same heads (65.4 cc)
10.4:1
___________________________________
If using the new ICON piston spec and no additional machining.
ICON 4.040" flat top piston with 5 cc valve relief. 1.550" compression height.
Piston would now measure .024" below deck.
Same heads.
Same gasket for the purposes of this comparison.
.050" PTH clearance.
10.0:1
___________________________________
Of course, substituting the composite gasket for a shim style gasket would recover that .010" lost with the new piston. The heads have the proper surface finish and are freshly milled. The block not so much. It was decked 20 years ago.
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Last edited by skinny z on Sun Jan 16, 2022 12:27 pm, edited 1 time in total.
Kevin
Re: ICON 9929 Piston Specs
My catalogues tell the same story although I've a 2011 version as well as the latest 2020 one I could find.
An overbore is most definitely needed. The piston skirts are deeply scratched and the bores are equally a mess. It was surmised by my guy that the lack of chamfer on the bottom of the bores led to bits of metal getting drawn up with the piston.
Not only that, but it's plain to see there's less than zero crosshatch remaining in places. I bet I'll find taper, out of round and barrel shapes when I measure. Not that it matters.
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Last edited by skinny z on Sun Jan 16, 2022 12:33 pm, edited 1 time in total.
Kevin
Re: ICON 9929 Piston Specs
I read what you're saying (although I think your first sentence might be the reverse of what you mean).ClassAct wrote: ↑Sun Jan 16, 2022 10:05 am If all you can get is a 1/16-1/16-3/16 ring pack I’d look for a different piston. There is no reason to run those big, heavy, clunky ring packs. I’d spend more money on pistons and rings and skip the 4 corner cooling. Rings reduce friction and save power. The 4 corner cooling is a fool’s errand.
I'd expressed my desire for a thinner ring pack and we'll see how that conversation plays out. So far, other than discussing the basics of what the new short block would entail, nothing is finalized.
We're also dealing with the lack of availability for a lot of these speed parts. It doesn't improve here in Canada either. In fact it's probably worse. The ICON piston is what that builder knows he can get (he was stuffing a block with a set during the course of our discussion).
Not to mention the incredibly poor dollar exchange we deal with.
That said, by most accounts the thinner rings are the way to go. OEMs chose that direction for a reason. I've read about the HP gained through reduced friction, etc. I admire the ease at which an entire rotating assembly can be spun around with only inch/lbs of effort required on the all out Stock and Super Stock engines.
But for a pedestrian guy like me, how much gain is there really though? And at what RPMs? Not that free HP is anything to complain about.
Mentioning weight, the ICON piston (the old version at least), despite being forged and with the 5/64ths rings, comes in lighter at 545/132 for 677 grams than the cast Speed Pro coming out which is 572/159 for 712 grams.
The weight of the ICON piston has yet to be determined officially. There's the .040" oversize to consider as well.
Waiting on my email inquiry.
Kevin
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Re: ICON 9929 Piston Specs
Take a look at the Autotec offering.
#1000104
Ring #AT4040
1.5-1.5-3 MM ring package.
-5cc valve reliefs.
Listed weight is 501 grams.
Listed comp. height is 1.560 in.
Listed comp. is 10.4.
#1000104
Ring #AT4040
1.5-1.5-3 MM ring package.
-5cc valve reliefs.
Listed weight is 501 grams.
Listed comp. height is 1.560 in.
Listed comp. is 10.4.
Re: ICON 9929 Piston Specs
There'll most certainly be additional conversations regarding the options available.
In those conversations, I'll be setting my CR limit which I prefer to keep at 10.2:1 or somewhat less. Not more.
The weight difference is of some concern as well. It'd be nice if another balance job isn't required if only from a cost perspective. I'm throwing money around at a couple of other projects and if I can save some here and there, I will.
In those conversations, I'll be setting my CR limit which I prefer to keep at 10.2:1 or somewhat less. Not more.
The weight difference is of some concern as well. It'd be nice if another balance job isn't required if only from a cost perspective. I'm throwing money around at a couple of other projects and if I can save some here and there, I will.
Kevin
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Re: ICON 9929 Piston Specs
skinny z wrote: ↑Sun Jan 16, 2022 12:01 pmLast build:
Speed Pro 4.030" flat top piston with 5 cc valve relief.
Measured piston below deck at .014" with a 1.560" compression height piston.
Victor Reinz/Mahle head gasket. .026" x 4.125".
.040" PTH clearance.
Measured 65.4 cc combustion chamber
10.2:1
CR 1.jpg
___________________________________
If using the old ICON piston spec and no additional machining other than the overbore:
ICON 4.040" flat top piston with 3.7 cc valve relief. 1.560" compression height.
Piston would maintain the .014" below deck measurement.
Same head gasket (.026" x 4.125").
.040" PTH clearance.
Same heads (65.4 cc)
10.4:1
CR 2.jpg
___________________________________
If using the new ICON piston spec and no additional machining.
ICON 4.040" flat top piston with 5 cc valve relief. 1.550" compression height.
Piston would now measure .024" below deck.
Same heads.
Same gasket for the purposes of this comparison.
.050" PTH clearance.
10.0:1
CR 3.jpg
___________________________________
Of course, substituting the composite gasket for a shim style gasket would recover that .010" lost with the new piston. The heads have the proper surface finish and are freshly milled. The block not so much. It was decked 20 years ago.
You do not have the required permissions to view the files attached to this post.
Re: ICON 9929 Piston Specs
Exactly my results as well.maxracesoftware wrote: ↑Sun Jan 16, 2022 1:54 pmSkinnyZ_CompRatios2.jpgskinny z wrote: ↑Sun Jan 16, 2022 12:01 pmLast build:
Speed Pro 4.030" flat top piston with 5 cc valve relief.
Measured piston below deck at .014" with a 1.560" compression height piston.
Victor Reinz/Mahle head gasket. .026" x 4.125".
.040" PTH clearance.
Measured 65.4 cc combustion chamber
10.2:1
CR 1.jpg
___________________________________
If using the old ICON piston spec and no additional machining other than the overbore:
ICON 4.040" flat top piston with 3.7 cc valve relief. 1.560" compression height.
Piston would maintain the .014" below deck measurement.
Same head gasket (.026" x 4.125").
.040" PTH clearance.
Same heads (65.4 cc)
10.4:1
CR 2.jpg
___________________________________
If using the new ICON piston spec and no additional machining.
ICON 4.040" flat top piston with 5 cc valve relief. 1.550" compression height.
Piston would now measure .024" below deck.
Same heads.
Same gasket for the purposes of this comparison.
.050" PTH clearance.
10.0:1
CR 3.jpg
___________________________________
Of course, substituting the composite gasket for a shim style gasket would recover that .010" lost with the new piston. The heads have the proper surface finish and are freshly milled. The block not so much. It was decked 20 years ago.
Now put a .015" gasket in there and the CR gets back to 10.2:1.
So all is not lost if that's the piston that ends up in the engine.
I'll explore my options though.
Kevin