Top Ends & Parts

OBR billet intake manifold for the G320RC and G340RC engines. We've found the big down side to a billet intake manifold is the transfer of heat from the cylinder to the carb. We've done a thick isolator similar to our V2 reed which has proven to not transfer heat or leak. Match porting to the cylinder has been improved over the stock intake manifold. You will need to use carb bolts about 5mm longer then your currently using due to the thickness of the isolator.

OBR billet intake manifold for all engines 22.5cc through 30.5cc. We've found the big down side to a billet intake manifold is the transfer of heat from the cylinder to the carb. We've done a thick isolator similar to our V2 reed which has proven to not transfer heat or leak. Match porting to the cylinder has been improved over the stock intake manifold. You will need to use carb bolts about 5mm longer then your currently using due to the thickness of the isolator.

OEM NGK spark plug for all CY and Zenoah engines from 22.5cc-30.5cc's

38mm Zenoah piston ring for the G320/340 engines.

Porting not shown in picture!

Full mod G320RC top end. Can be installed onto a stock G320RC engine or is a replacement top end for full mod engine 6300. View engine description for modifications done to top end. https://oneillbrothers.com/products/6300-7-7hp-full-mod-zenoah-g320rc-31-8cc-engine?_pos=1&_sid=6be5a34a3&_ss=r

Top end comes complete with:

Ported cylinder

Modified piston

piston ring

Cylinder gasket

Transfer port/skavenging covers

Wrist pin

Thrust/piston pin washer

c-clip set 

<p>These are not a copy of the stock Zenoah transfer port plates. These are a performance upgrade that add up to 0.5hp. Billet transfer port covers for the G320RC and G340RC engines(not compatible with 22.5cc - 30.5cc engines). The angles and volume of these plates has been changed to increase power. We've seen a power gain on both stock and ported engines. Clutch and flywheel side plates are included with hardware. Sealant is required when installing.</p>

Replacement fully modified G340RC top end  for engine 6310. A +2mm stroke crank is required for this top end.

Replacement fully ported top end for 30.5cc reed engines sku 6316.

Replacement fully modified top end for engine 6274. This top end can also be used to upgrade a stock G290RC. A +2mm stroke crank is required.

Replacement top end for our full mod engines. This top end is fully ported and modified and can be used to upgrade a stock GP460. The 47cc version requires a +1mm stroker.

<p>(Our porting is not shown in picture)&nbsp;</p> <p>PROSTOCK - An affordable/mild version of a full mod. The PROSTOCK's are rated at 5-5.5hp, full mod's 6-6.5hp, and full mod long rods 7-7.5hp.&nbsp;<span>We guarantee performance of this top end to be as much if not more than similary priced ported top ends from our competitors.&nbsp;</span></p> <p>The PROSTOCK line has replaced the Race Ported line. The PROSTOCK engines produce more power than the race ports and are more economical.</p> <p>To keep costs down, we focused our time tuning this top end to the areas that would yield the most power possible while maintaining reliability and ease of use. At OBR, we do not believe in stacking or using thick cylinder gaskets. We always machine and reshape the combustion chamber on our stroked engines. To help with reliability, we also relieve the piston. Piston reliefs help reduce the chances of the piston seizing on the exhaust side of the cylinder when running lean or hot. We were the first in this industry to do the piston relief several years ago.</p> <p>Being that this line is a budget/starter top end, we tuned it to run well with any exhaust. We kept in mind that you may not have a pipe. We have seen great performance with everything from an HPI can exhaust to a pipe. If upgrading to a pipe, we recommend the Jetpro Boss. For those of you that are new to ported engines, we shot for ease of use. With proper installation a PROSTOCK engine is very easy to start and to tune the carb.&nbsp;</p> <p>We have left the porting open on this top end. At any time, you may send your engine/top end in to us to be upgraded to a full mod or a full mod long rod.</p> <p><span>*Tech notes: We have ported this top end to not need a modified crankcase. We recommend a standard Zenoah 4 bolt crankcase. This top end requires that you use a +2mm stroker crankshaft.&nbsp;</span></p>

<div class="std"> <p>This long block now comes with a TR/OBR billet crankcase at no extra cost.&nbsp;<span>Every long block or engine is now CNC ported and hand finished. CNC porting and hand finishing is all done in-house by the OBR staff. We do not contract out any of our porting so every engine is modified to our exact specifications. We are able to offer higher accuracy this way as well as more power. Our CNC machine has allowed us to take our porting to the next level due to us being able to do cylinder work that is not possible to do by hand.</span></p> <p>Full Mod -&nbsp;Our top of the line engines.</p> <p>Check out this engine in action: <a href="http://www.youtube.com/watch?v=NhQ50CvSVIM">http://www.youtube.com/watch?v=NhQ50CvSVIM</a>&nbsp;</p> <p>The full mod 30.5cc has proven to be one of&nbsp;the most&nbsp;popular engines we build. This is a great way to&nbsp;upgrade to a full mod&nbsp;4 bolt&nbsp;engine and save some cash. To&nbsp;complete this long block you will need a flywheel, coil, covers, carb and&nbsp;clutch. All of thse items can be removed from your stock engine. Our long blocks come with a complete 4 bolt Zenoah crankcase with bearings, seals, 2mm stroker&nbsp;crank and&nbsp;full mod top end. All long blocks come assembled as shown in the picture.&nbsp;&nbsp;</p> <p>With the higher reliability of the&nbsp;4 bolt Zenoah engines we were able to&nbsp;achieve more power with out sacrificing reliability. We put all of the knowledge that we have picked up from years of dyno and field testing and came up with a monster.</p> <p>The following porting and machined has been performed to this long block:</p> <p><br />1. Machine combustion chamber for a proper squish clearance without stacking cylinder&nbsp;gaskets<br />2. Reshape piston <br />3. Lighten piston <br />4. Relieve&nbsp;piston to prevent seizes&nbsp;<br />5. Modify intake port for better flow <br />6. Adjust intake&nbsp;duration to our specs <br />7. Resurface all ports <br />8. Modify transfer ports for better flow <br />9. Enlarge and reshape exhaust port <br />10. Adjust exhaust&nbsp;duration to our specs <br />11. Re-bevel all porting and stock bevels to prevent damage to the piston and/or cylinder</p> <p>&nbsp;<br />This long block fits:</p> <p>Off-road Rc Cars: HPI Baja 5B/5T/5SC, MCD, Rampage, FG Marder, FG Marder Race, FG Monster Beetle, FG Monster Beetle Pro,FG MT5,FG Stadium Truck, Duratrax Firehammer, Carson Attack, Smartech Traveller,FG Leopard, XTM, Leopard Race, FG Leopard STX, FG Marder Beetle, FG Pajero and most other large scale cars.</p> <p><br />On-road Rc Cars: MCD, FG Evo,FG Sportline, HARM,FG F-1 Competition and most other large scale onroad cars.</p> </div>

Replacement 36mm piston ring. This ring is compatible with the G290RC based engines including 28.5cc, 29.5cc and 30.5cc.

Replacement Piston for G320RC & G340RC Reed Case Engines

Replacement Needle Bearing for G320RC & G340RC 38mm Piston

Replacement full mod or signature series twin top end set. These top ends have been machined for twin use and our billet heat sink. Full mod is our production CNC porting and will have good power from torque through top rpm's. The signature series are ported more aggressively and will have quite a bit more power than the full mod version. We also offer custom tuning on any signature series top ends/engines upon request at no additional charge. If ordering signature series porting please email us if you would like custom tuning. 

<p>This is a brand new race ported 30.5cc top end. This kit comes with everything need to turn your motor into a beast except for a 2mm crank. To start we machine the cylinder for the 2mm stroker and for a proper squish clearance with out stacking gaskets. This allows the motor to rev higher and still have a massive amount of torque. All of our port work is done by hand except for machining the cylinder.&nbsp;</p> <p><br />This big bore kit will fit the following Motors/Cars/Trucks:</p> <p><br />Motors: (2mm Stroker Required) G230RC, G260RC, CY23rc,CY26rc, CY27rc, CY29rc,GP290, 27cc Head Kit Motor, 29cc Head Kit Motor He23hp, He26hp.</p> <p>Off-road Rc Cars: HPI Baja 5B/5T/5SC, FG Marder,FG Marder Race,FG Monster Beetle,FG Monster Beetle Pro,FG MT5,FG Stadium Truck, Duratrax Firehammer, Carson Attack, Smartech Travel,ler,FG Leopard, XTM<br />Leopard Race,FG Leopard STX,FG Marder Beetle,FG Pajero, And most other large scale cars</p> <p>On-road Rc Cars: FG Evo-4,FG Sportline, HARM,FG F-1 Competition, And most other large scale on-road cars.</p>

Replacement Piston C-Clips for G320RC & G340RC 38mm Piston

Replacement Thrust Washers for G320RC & G340RC 38mm Piston

Porting not shown in picture!

Full mod G340RC top end. Can be installed onto a stock G320RC(with +2mm stroke crank) engine or is a replacement top end for full mod engine 6309. 

Top end comes complete with:

Ported cylinder

Modified piston

piston ring

Cylinder gasket

Transfer port/skavenging covers

Wrist pin

Thrust/piston pin washer

c-clip set 

Replacement 36mm Piston for G290 Reed Case Engines. Fits 28.5cc-30.5cc Reed Engines

Replacement 36mm Piston for 30.5cc G290 Engines

Replacement piston C-Clip set for all CY and Zenoah engines 22.5cc's-30.5cc's.

Replacement fully modified G320RC reed top end  for engine 6304 and long block 6323. This top end must be used on a stock stroke G320RC crankshaft.