National Runner Up Red Plate Build Specs

Big Chris

Premium User
So, for those of you who are interested.
One of red plate clones went to the 2019 Maxxis Thunder in the Valley Nationals and took second place. Andy Partridge of Khemical Khaos did the tire prep. And Mason from Keystone Heights, FL was the wheelman. Jason, Mason's father, was the crew chief, coach, and chassis setup man. Mason's invite came after winning the Big O Tribute race in Blacksburg, South Carolina. Mason also is the two time Callahan Speedway rookie champ.

So in an effort to help the little guys out there, I thought I would share some of this particular engines build components. All the parts for this build came from either the Box Stock Project or ARC Racing.

The engine block is a 2019 vintage Box Stock Engine.
The head is a #223 casting head, and as per the rule set in FL, it is an AKRA spec head w/o porting. 3 angle valve job at 30/45/60 degree. This head was cut to ensure flatness, and to set combustion chamber cc. Pro tip combustion chamber cc was not set to the minimum of 26.5cc
Piston is a stock BSP piston at stock sizing. Cylinder to piston wall clearance was set to .0035" as measured at wrist pin centerline. Rod is a stock BSP cast rod.
Top ring end gap was .018" second ring end gap was .026" and oil control ring package was stock.
Cam was a BSP4, ILC was set to my spec.
Light weight lifters, light weight retainers, and square tip rockers were used. Valve lash was set to my spec. Pro tip, valve lift was not set to the max of .238"/.242" Springs were seasoned (pre fatigued) dyno green stripes.
ARC 6689 flywheel was used, with no key. Ignition timing was set to my spec, and coil air gap was set to my spec.
ARC 6934 air filter adapter was used, and of course an ARC red plate was used. Carb jetting and blueprinting was set to my spec.
RAPP Fab thick flange weenie pipe was the header of choice and the spec RLV screw in muffler rounded out the exhaust system.

IMG_3391.JPG
 
Thanks Chris, some excellent info for the guys out there still trying to do their own thing. Much appreciated!

My son has raced this kid at our local tracks and we have beat him every time... lol. They can't get the setup for these wet tracks that need sponge tires and some wheelin' But he's bad fast at sealed, hard tracks!
 

Kart0023

Member
I don’t personally know Chris, but I did just ship my kids green and purple plate motors to him for rebuild/freshen. I emailed him and he responded quickly with his phone number. We talked over the phone and he seems as honest and fair as they come and offered to dyno my motors and make his recommendations to improve HP. And his post on helping the little teams just backs up what I already thought about him. Glad to see there are still good people out there willing to help out.
 

Big Chris

Premium User
how much better is the rapp thick vs the thin one?
Quite honestly, I've tested most* of the weenie pipes on the market, and IMO, there isn't a whole lot of power differences to be had from one weenie pipe to the next. I have had some instances where other weenie pipes have broken at the weld where it meets the mounting flange. So here are my thoughts.

The RAPP thick flange weenie pipe is pricey but : Offers a nice transition between the "D" shaped exhaust port in the head and the round profile of the pipe. This is a feature just not possible on the thin flanged pipes. The welds on the RAPP pipe are almost a work of art, and there is a nice brace btwn the mounting flange and the end of the pipe. Also it has nice tab welded on to the end so you can secure the muffler via a pipe clamp.

*most means pretty much all of them......
 
Quite honestly, I've tested most* of the weenie pipes on the market, and IMO, there isn't a whole lot of power differences to be had from one weenie pipe to the next. I have had some instances where other weenie pipes have broken at the weld where it meets the mounting flange. So here are my thoughts.

The RAPP thick flange weenie pipe is pricey but : Offers a nice transition between the "D" shaped exhaust port in the head and the round profile of the pipe. This is a feature just not possible on the thin flanged pipes. The welds on the RAPP pipe are almost a work of art, and there is a nice brace btwn the mounting flange and the end of the pipe. Also it has nice tab welded on to the end so you can secure the muffler via a pipe clamp.

*most means pretty much all of them......
I asked because I had a thick one and ordered one and ended up with the thin one. Haven't put it on yet. But I agree the thick flange is pretty.
 

flattop1

Dawg 89
So, for those of you who are interested.
One of red plate clones went to the 2019 Maxxis Thunder in the Valley Nationals and took second place. Andy Partridge of Khemical Khaos did the tire prep. And Mason from Keystone Heights, FL was the wheelman. Jason, Mason's father, was the crew chief, coach, and chassis setup man. Mason's invite came after winning the Big O Tribute race in Blacksburg, South Carolina. Mason also is the two time Callahan Speedway rookie champ.

So in an effort to help the little guys out there, I thought I would share some of this particular engines build components. All the parts for this build came from either the Box Stock Project or ARC Racing.

The engine block is a 2019 vintage Box Stock Engine.
The head is a #223 casting head, and as per the rule set in FL, it is an AKRA spec head w/o porting. 3 angle valve job at 30/45/60 degree. This head was cut to ensure flatness, and to set combustion chamber cc. Pro tip combustion chamber cc was not set to the minimum of 26.5cc
Piston is a stock BSP piston at stock sizing. Cylinder to piston wall clearance was set to .0035" as measured at wrist pin centerline. Rod is a stock BSP cast rod.
Top ring end gap was .018" second ring end gap was .026" and oil control ring package was stock.
Cam was a BSP4, ILC was set to my spec.
Light weight lifters, light weight retainers, and square tip rockers were used. Valve lash was set to my spec. Pro tip, valve lift was not set to the max of .238"/.242" Springs were seasoned (pre fatigued) dyno green stripes.
ARC 6689 flywheel was used, with no key. Ignition timing was set to my spec, and coil air gap was set to my spec.
ARC 6934 air filter adapter was used, and of course an ARC red plate was used. Carb jetting and blueprinting was set to my spec.
RAPP Fab thick flange weenie pipe was the header of choice and the spec RLV screw in muffler rounded out the exhaust system.

View attachment 6887
This and careful assembly, should produce a good engine .
Pre fatigued springs , out of a mule engine ?
 
Chris-

What is your opinion of the new JT-223 head in unported form? is it as good as BSP and others are touting? Do you feel it is a good head for restricted classes?
 

Big Chris

Premium User
Pre-fatigued springs is something I've been researching and doing for long time, and is a result from testing back in 2015. This has taken me years to dial it in. Begin at post #43 of this thread. Sorry but photobucket hijacked the photos.


As for the 223 head:

I've gone on record to say that the 181 head from Box Stock was THE head to have for restrictor plate racing. I'll also go on record to say that the 223 is as good if not better. I mean an unported one went to the nats.

Everyone gets hung up on flow numbers, cross sectional area, runner volume, etc. Here is what I know from a metric ton of data I personally collected and study regularly. A great flowing head on the SF60 doesn't always impress on the dyno. But great numbers of the dyno perform great on the track. For whatever the reason, the 223 not only flows great, but makes solid hp numbers.
 
Pre-fatigued springs is something I've been researching and doing for long time, and is a result from testing back in 2015. This has taken me years to dial it in. Begin at post #43 of this thread. Sorry but photobucket hijacked the photos.


As for the 223 head:

I've gone on record to say that the 181 head from Box Stock was THE head to have for restrictor plate racing. I'll also go on record to say that the 223 is as good if not better. I mean an unported one went to the nats.

Everyone gets hung up on flow numbers, cross sectional area, runner volume, etc. Here is what I know from a metric ton of data I personally collected and study regularly. A great flowing head on the SF60 doesn't always impress on the dyno. But great numbers of the dyno perform great on the track. For whatever the reason, the 223 not only flows great, but makes solid hp numbers.
Awesome! Thank you again for the great info!
 
So, for those of you who are interested.
One of red plate clones went to the 2019 Maxxis Thunder in the Valley Nationals and took second place. Andy Partridge of Khemical Khaos did the tire prep. And Mason from Keystone Heights, FL was the wheelman. Jason, Mason's father, was the crew chief, coach, and chassis setup man. Mason's invite came after winning the Big O Tribute race in Blacksburg, South Carolina. Mason also is the two time Callahan Speedway rookie champ.

So in an effort to help the little guys out there, I thought I would share some of this particular engines build components. All the parts for this build came from either the Box Stock Project or ARC Racing.

The engine block is a 2019 vintage Box Stock Engine.
The head is a #223 casting head, and as per the rule set in FL, it is an AKRA spec head w/o porting. 3 angle valve job at 30/45/60 degree. This head was cut to ensure flatness, and to set combustion chamber cc. Pro tip combustion chamber cc was not set to the minimum of 26.5cc
Piston is a stock BSP piston at stock sizing. Cylinder to piston wall clearance was set to .0035" as measured at wrist pin centerline. Rod is a stock BSP cast rod.
Top ring end gap was .018" second ring end gap was .026" and oil control ring package was stock.
Cam was a BSP4, ILC was set to my spec.
Light weight lifters, light weight retainers, and square tip rockers were used. Valve lash was set to my spec. Pro tip, valve lift was not set to the max of .238"/.242" Springs were seasoned (pre fatigued) dyno green stripes.
ARC 6689 flywheel was used, with no key. Ignition timing was set to my spec, and coil air gap was set to my spec.
ARC 6934 air filter adapter was used, and of course an ARC red plate was used. Carb jetting and blueprinting was set to my spec.
RAPP Fab thick flange weenie pipe was the header of choice and the spec RLV screw in muffler rounded out the exhaust system.

View attachment 6887
When this engine was built, was it set up for a spec gear or open gear? When I say spec gear, I am talking about the typical 4 teeth too many on the rear, and a few less in the front than what it should be, 6300 rpm red plate.
 
Last edited:
Chris,

I notice your ring gaps seem unusually large for what I see as norm, have you done some testing on that area? .018" on the top ring is significantly larger than what I run my plate engines at (usually .005-.008) I also keep my second ring tighter at .010-.015. Interested in your findings if you care to share. Totally understand if you don't!
 
So, for those of you who are interested.
One of red plate clones went to the 2019 Maxxis Thunder in the Valley Nationals and took second place. Andy Partridge of Khemical Khaos did the tire prep. And Mason from Keystone Heights, FL was the wheelman. Jason, Mason's father, was the crew chief, coach, and chassis setup man. Mason's invite came after winning the Big O Tribute race in Blacksburg, South Carolina. Mason also is the two time Callahan Speedway rookie champ.

So in an effort to help the little guys out there, I thought I would share some of this particular engines build components. All the parts for this build came from either the Box Stock Project or ARC Racing.

The engine block is a 2019 vintage Box Stock Engine.
The head is a #223 casting head, and as per the rule set in FL, it is an AKRA spec head w/o porting. 3 angle valve job at 30/45/60 degree. This head was cut to ensure flatness, and to set combustion chamber cc. Pro tip combustion chamber cc was not set to the minimum of 26.5cc
Piston is a stock BSP piston at stock sizing. Cylinder to piston wall clearance was set to .0035" as measured at wrist pin centerline. Rod is a stock BSP cast rod.
Top ring end gap was .018" second ring end gap was .026" and oil control ring package was stock.
Cam was a BSP4, ILC was set to my spec.
Light weight lifters, light weight retainers, and square tip rockers were used. Valve lash was set to my spec. Pro tip, valve lift was not set to the max of .238"/.242" Springs were seasoned (pre fatigued) dyno green stripes.
ARC 6689 flywheel was used, with no key. Ignition timing was set to my spec, and coil air gap was set to my spec.
ARC 6934 air filter adapter was used, and of course an ARC red plate was used. Carb jetting and blueprinting was set to my spec.
RAPP Fab thick flange weenie pipe was the header of choice and the spec RLV screw in muffler rounded out the exhaust system.

View attachment 6887
so used springs are better ( Pre-fatigued springs )?
 
Pre-fatigued springs is something I've been researching and doing for long time, and is a result from testing back in 2015. This has taken me years to dial it in. Begin at post #43 of this thread. Sorry but photobucket hijacked the photos.


As for the 223 head:

I've gone on record to say that the 181 head from Box Stock was THE head to have for restrictor plate racing. I'll also go on record to say that the 223 is as good if not better. I mean an unported one went to the nats.

Everyone gets hung up on flow numbers, cross sectional area, runner volume, etc. Here is what I know from a metric ton of data I personally collected and study regularly. A great flowing head on the SF60 doesn't always impress on the dyno. But great numbers of the dyno perform great on the track. For whatever the reason, the 223 not only flows great, but makes solid hp numbers.
Hmm, You relate dyno numbers and on track performance. I agree with you to a point, but it seems to me that doesn't always apply to the small plate motors, especially red. I put a red plate together to run Daytona with a few weeks back. The pig didn't make enough power to run piss ants motorcycle up a 1% incline, yet it turned right at 6500 rpm on the racetrack, put it back together and ran it on a 1/3 mile dirt track and turned it just shy of 6500 rpm again. I am pretty sure if the chain would have fell off of the go kart it would not have turned any harder lol. Nevermind, rereading your post and I see you said "impress on the dyno" , and you did not say peak power. I jump to conclusions sometimes.
 
Hmm, You relate dyno numbers and on track performance. I agree with you to a point, but it seems to me that doesn't always apply to the small plate motors, especially red. I put a red plate together to run Daytona with a few weeks back. The pig didn't make enough power to run piss ants motorcycle up a 1% incline, yet it turned right at 6500 rpm on the racetrack, put it back together and ran it on a 1/3 mile dirt track and turned it just shy of 6500 rpm again. I am pretty sure if the chain would have fell off of the go kart it would not have turned any harder lol. Nevermind, rereading your post and I see you said "impress on the dyno" , and you did not say peak power. I jump to conclusions sometimes.
You're purposely turning red plate engines 6500rpm? Holy cow, I don't even turn my purple plates that hard...
 
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