Box Stock

Both rtc 6 and rtc 9 heads

B

Boostedego

New member
Ok i have rtc 6 and rtc 9 heads i have heard the rtc 6 heads are great heads and with a little smoothing there the best flowing heads, so what about the rtc 9 head and how do these compare to the 14 cc hi comp head that i have would really want to run the best one ?
 
The RTC-9 will most likely already outflow the 14cc head you have, with a little port work the rtc-9 and rtc-6 heads both make really nice heads for modified or open predators. The 6 and 9 are basically the same head, the 9 is just the most recent casting of the rtc-6 and has stainless valves and the ports are a little cleaner from what i have seen and can tell, these valves and retainers that come in the RTC heads can handle stiffer spring pressures alot better than the hemi style retainers and valves do, i have an engine with the rtc-6 head that is ported and polished and has the stock valves and retainers that came in it, with dual springs that has been running for over a season without a single problem, very strong running engine and has won alot of races.
 
W5R said:
The RTC-9 will most likely already outflow the 14cc head you have, with a little port work the rtc-9 and rtc-6 heads both make really nice heads for modified or open predators. The 6 and 9 are basically the same head, the 9 is just the most recent casting of the rtc-6 and has stainless valves and the ports are a little cleaner from what i have seen and can tell, these valves and retainers that come in the RTC heads can handle stiffer spring pressures alot better than the hemi style retainers and valves do, i have an engine with the rtc-6 head that is ported and polished and has the stock valves and retainers that came in it, with dual springs that has been running for over a season without a single problem, very strong running engine and has won alot of races.
Click to expand...

Thank you i guess i will be milling the head as well for more compression do you how much im able to remove being i have a stock length rod with.010 gasket ?
 
If you mill the head, you will have to run shorter pushrods.... depending on how much you mill the head...
I do my own heads can't say I do anything special.... but on my findings the 14cc head flows a bit less at lower lift and not bad in the higher lift...
The 18cc heads and 22cc heads flow more sooner and at lower lift than the 14cc head...
Even if you unshroud the 14cc head it is tough to get it to flow as much as the others at lower lift...

Really depends on your entire build...and the track you will be racing at most...
I have tried too many different combos and they all achieve the same lap times, at different RPMs...
You can have a motor that makes most of its power at 4000-7000rpm, and another 5000-9000rpm...
 
Boostedego said:
Thank you i guess i will be milling the head as well for more compression do you how much im able to remove being i have a stock length rod with.010 gasket ?
Click to expand...

You can mill just about as much as ud like! I have an rtc-6 that's milled .115 with the dished piston... my guess is .070 to .080 off will land u around 14cc
 
If you do that, you are going to need more octane in your fuel, 87 octane, if that's what you use now, will not get it. You might even need race gas.
 
Right now as she sits with the 14cc head not sure about the ccs in the chamber, but im using 93 sometimes a bit more octane and has been running fine but thank you for all the info i will be putting my 14 cc head a side and will start milling and porting my 6 or 9 head whats crazy is i have noticed great difference between rtc 6 and 9 heads to other heads i have used and even the hi comp 14 cc head i thought i was loosing it when i started building these engines thinking why does it feel like these engines breath better with the stock heads but then i got info about them so i really looked at them and they are pretty clean right out of the box.
 
That head I did some work to and also installed a 28.5 intake valve...
You may end up with a bit more or less CC's than I did...
Generally on a 22cc head when milled .090 you are looking around 13.5cc's depending...

Also will have to use shorter pushrods if milling that much...
I had GX160 lifters laying around so I used those instead of shorter pushrods...
 
Ok thanks for the info looks like it will be a little bit before i can have the head milled i have to buy the right router bit to make a flush cut.
 
With .09 off a 22cc head I either run 5.175 pushrods and regular lifters or stock length pushrods and gx160 lifters...
 
You must log in or register to reply here.
Back
Top