big bore pipe on 310/295

[bigmatt61]

Does anyone have any experience with running a big bore pipe on a 295/310 cylinder?
If so, what carb, reed, porting and airfilter setup did you use?
Any of the engine guru's have an opinion on this?

Matt

[matt250r21]

From what I have read from acecarlos, a big bore pipe kills top end on any engine smaller then 370cc. I have no first hand experience on this, all my Rs are 265s.

[bigmatt61]

That seems to be contradictory as to why Curtis and Arlen made BB pipes, doesn't it?
Surely there has to be a performance gain on motors under 370. IE; 330 and up.
I'm just wondering if they would work on a "310" as well. Would there be a performance gain or would it be detrimental.

Matt

[matt250r21]

Yeah, I know Sparks and LRD made 330 BB pipes, but ESR dosn't and they seem to be into 310s and up. Seems to be two schools of thought on this.

[265 sleeper]

Depends on port timing . Sometimes reg pipes work better than BB pipes.

[Gresham250R]

I'd say get on Facebook and look up LED Performance and just ask Arlen! Just a simple thought...

[mx91a]

It might work OK if you are looking for great low end power and throttle response but the larger diameter stinger will reduce your EGTs and hurt top end power.

I have a Sparks MX pipe with 1.25" OD stinger for sale if you are interested in trying it out...

[wes350x]

Originally posted by mx91a
It might work OK if you are looking for great low end power and throttle response but the larger diameter stinger will reduce your EGTs and hurt top end power.

I have a Sparks MX pipe with 1.25" OD stinger for sale if you are interested in trying it out...

I spoke with Arlen the other day to get a quote for a sphinx build and he was telling I needed a pipe with a larger I.d. than a standard size. He also stated that ESR want to a thicker walled pipe for for the pipe they use to the stinger to create more pressure cause it will make more power but it overheats the motor way too easily.

I've personally ran trx11 and a trx5 on a ESR 310 and liked the 5 better. The 11 wasn't horrible but just a real top end pipe. The 5 was great at everything.

[red88r]

All I know is that we had a LRD pipe/silencer on our Duncan 340pv for awhile. Then we put on a Duncan/pipe silencer and what a difference it made. Don't know why but there must be a reason LRD makes them for their big bores and Duncan does not.

[C-LEIGH RACING]

Porting & pipes, which one, is dependant on what rpm range your wanting the most power produced.
Lower rpm ranges, where the flow is slow up through the ports, but probably more compact, so your stuffing more on top of the piston, you'll need that larger stinger to bleed off the pressure quick.
The flow & everything is moving slower at lower rpms so you dont what any restriction in the pipe.

Another thing, the heat, like already mentioned.
Lower rpm range engines, will get ran longer amounts of time, build more heat than say a normal drag ported & piped engine will, so in turn you need the larger stinger so that heat can be removed, blown out of the pipe.

So, think about at what rpm range your going to be running the engine the most & then go from there.

I would say though, unless you have a wad of money burning holes in your pocket & just got to get it out, if a big bore pipe all you have, you might be surprised how well it will perform.

295/310 high rpm,
39/42mm carb
V force or a cage with thick reed petals
small stinger pipe.

295/310 low rpm,
36/39mm carb
Boysene Rad valve or any cage that will flow a lot with 2 stage thin reeds.
dependant on RPM the type of pipe so anything from the LED big bore to any of the midrange ESR pipes.
Neil

[bigmatt61]

Thanks for your input Neil.
I have all the stuff you listed in both of those setups along with 2 Sparks BB pipes. One mx 330 and one TT.
I have an LRD 310 pv with mx porting, long rod, CT reed cage, 38 as with a team B pipe currently on my "treebeater".
I was really doing a "what if ? " but, could I gain more bottom end grunt for the woods with that BB mx pipe on there?

Matt

[fish10782]

I ran the lrd adjustable big bore pipe on my psi 310. usually I run the curtis sparks TT pipe. so the differences were huge on my machine. the tt pipe revs to the sky makes power high rpm's as well. the bb pipe was low to mid only!! the wheeler would easily pull a 6th gear wheelie. the adjustable pipe portion didn't seem to make a difference pulled in or out felt about the same to me. NOW what I'd like to do is cut the stinger off put smaller and invert it but don't have the balls to cut that pipe up.. so it sits in my shop. ran twice ceramic coated black :D it's hanging on the wall like art.

[C-LEIGH RACING]

Originally posted by bigmatt61
Thanks for your input Neil.
I have all the stuff you listed in both of those setups along with 2 Sparks BB pipes. One mx 330 and one TT.
I have an LRD 310 pv with mx porting, long rod, CT reed cage, 38 as with a team B pipe currently on my "treebeater".
I was really doing a "what if ? " but, could I gain more bottom end grunt for the woods with that BB mx pipe on there?

Matt

Probably not.
Best bottom end pipe I know, one I've used the most, CT midrange MX. That is one heck of a bottom end pipe, but dont expect it to rev out much.
You take that CT midrange, a good midrange port along with 220~240lbs compression, make a stump pulling grunt engine.
Dont worrie about rpm, just stick on a 15/34 & shift gears cause you'll run out of them quick.
Neil