clone/rocker Head upgrade??

[Lkerley]

new to the bsp.with the stock rod turning 5300 and under mostly a cruiser.will the stock rod tend to stress and break with an upgrade to a 18cc or 14cc head maybe shaved and a 1.3 rocker/ push guide plate upgrade is there a max you should not go over with the stock rod...just running the bsp4 cam and pvl wheel.and should I stick with a red stripe type 10.8 spring or should I go to 18 lb springs or is that overkill..thks for any info and help.

 

[GClary]

I have turned the stock rods in excess of 7,000 rpms , and many say that is its limit before it goes to getting funky . With the build your talking about I would upgrade the rod , just to be on the safe side . You should be good with the 10.8 's .

 

[racinnut15xm]

Seems like most of the failures ive seen are the rod galling to the crank. On springs i would get them based off what cam you are running. BSP4 is probably fine with 10.8's, if you don't have rules shim them closer to coil bind.

 

[Lkerley]

not going to be running high rpm
Im wondering if I raise the compression 10.0 or higher will that cause stress enough to cause failure...this is just a toy to ride around on

 

[racinnut15xm]

Oh man i would just take the governor out and roll with it. Someone will hurt themselves with much more than that. Harder to find fuel when you go to raising compression and cost more per mile to ride.

 

[Lkerley]

yeah the governor is out.it hasnt been turned over 5200 yet with a 63/13 gear.was thinking of putting the 1.3 rockers on and change the guide plates and milling .050 off the head.maybe that would pep it up at lower rpm's.worried that raising compression might stress that stk rod even at low cruising rpm's?

 

[mike97760]

If you're just cruising at lower rpms than racers use, why the rocker change and milling the head?

 

[racinnut15xm]

yeah the governor is out.it hasnt been turned over 5200 yet with a 63/13 gear.was thinking of putting the 1.3 rockers on and change the guide plates and milling .050 off the head.maybe that would pep it up at lower rpm's.worried that raising compression might stress that stk rod even at low cruising rpm's?

Stock rod held up to 14-1 6000rpm in multiple motors ive known of. Do you have a flywheel key in it? Throw a washer under the spring to bring the spring pressure up some on the 10.8's with that cam it should be plenty to turn 6000ish.

 

[jsf74]

For this application I would just change the gearing. Its not like were looking for lower lap times you probably just want it to rip on the hit! Make it loud with a good pipe and gear it to rip!

 

[Lkerley]

For this application I would just change the gearing. Its not like were looking for lower lap times you probably just want it to rip on the hit! Make it loud with a good pipe and gear it to rip!

yes.i have the gearing right..and yes this just a show type kart to ride at car shows,drag races etc.
I guess what I'm asking is will the 1.3 rocker set up give it enough extra lift to give it some loping sound.like a bigger cam?
and will shaving .050 off the head.require an arc rod upgrade?

I was hoping the 20% or so extra lift would give me what I'm looking for.

the motor is stock from bsp with the bsp4 cam.i put the pvl wheel on it 32 deg.of timing,.750 header,and a pk1b tilly on it..