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-   -   GRP... Engine... Thread... (https://www.rctech.net/forum/offroad-nitro-engine-forum/211114-grp-engine-thread.html)

Bigedmond 03-03-2009 12:02 PM

I run GRP is both buggy and truggy, same plug, just different pipe. I tune for useable power, but my temps are insanely low. But to say they dont have the power is bull. My rc8t has been know to pull wheelies with the AE 2035 pipe.

[email protected] 03-03-2009 12:02 PM

For break in I am going to try and heat cycle my non tuned version, so as you guys say these motors dont get above 200 should I just cover the head with aluminum foil to get it up there? Or should I let it be?

jamiekerr14 03-03-2009 12:18 PM

1st, Heat the engine case-Not the Fins to around 200f Then, quickly get the engine running.. and get temps to 200f.. As soon as possible.. And moniter the temps alot.. and continue with the heat cycle method. Tin foil, is good.. with my V-Spec I had to take it off.. after a tank or 2.. as I used the OS heat cycle version, where you run it only slightly richer.. but get the temps to 200 as soon a possible, less stress on the engine that way.

Frank L 03-03-2009 02:38 PM


Originally Posted by Bigedmond (Post 5504760)
I run GRP is both buggy and truggy, same plug, just different pipe. I tune for useable power, but my temps are insanely low. But to say they dont have the power is bull. My rc8t has been know to pull wheelies with the AE 2035 pipe.

What kinda run time are you getting with thatbae pipe in the truggy?

tony montana 03-03-2009 03:29 PM

when ever I break in a engine I cant get it up in temp. Do you guys idle the first tank or what? If so do I need to lean the bottom out to get it up in temp?

[email protected] 03-03-2009 03:39 PM

On a normal engine it usually isnt hard. Put tinfoil on the head, or just lean the top a little. Any more answers on my q up a few posts?

Fierle03 03-03-2009 03:43 PM

For break in idle a few tanks through it with the head wrapped to keep the heat in then throw it down on the driveway/street. keep it kinda rich and just varry the throttle driving around.

Fierle03 03-03-2009 03:45 PM

oh and make sure you preheat the motor, its very important you do that. It will make the internals expand and prevent putting a lot of strain on the con rod, piston and sleeve.

tony montana 03-03-2009 04:19 PM

yeah I was planning on wraping the head with foil and using my heat gun. I just want to this engine to last the rest of the season

[email protected] 03-03-2009 04:35 PM

same I am going to try and do this heat cycle method. Any feedback would be appreciated.

Wrap head in aluminum foil and preheat o 180-200
Start the car and let it sit a minute or so and get temps up and keep an idle.
Put the car down and run it for 3 minutes varying throttle and keeping temps at 200
Bring it in and let it cool at BDC(Repeat step 5 times)
Take the foil off the head and lean the top end slightly and restart
Run the car for 4 minute cycles varrying throttle and keeping temps at 200 and letting the engine cool at BDC in between runs(repeat 4 times)

Then is should be good!!!

zixxer 03-03-2009 05:02 PM

i kinda tried to hint around the way i break a new motor in no matter what engine ...im gonna try and list it as best i can ...i have broke engines in in different way especially when i first started with a sportwerks.26 which says crank it throw it down run it with much smoke coming out of pipe ....:lol:then i tried the method mentioned above from johnny cool guy ....because it was listed as do this for o.s. motors ...when people were not getting good longevity out of them ...i ended up finally after 5 motor break ins over the past 2 years with this ...it works it is sound and i have never had a motor that blew up prematurely ....here it is
----wrap the head in aluminum foil and a cut sock
----dont touch the stock settings before you try to start it
----if it doesnt start lean the lsn an hour then try again ...and repeat ....if it doesnt start after a total of 1/4 turn lean ...check things out you may have another problem
----once it starts keep a very close eye on the temp ...
----as soon as the temp reaches 200 degrees or over let it idle for about a minute
----shut it off and drop the flywheel to bdc ....
----let cool all the way back to ambient temp
----do this twice ...thats 2 super quick heat cycles
----crank motor and let idle at a temp that is acceptable for your motor ...
grp 180-200 range , gotechs 200-240 range
----idle 2 tanks this way keeping the temp at your certain temp for your engine ....
--- you will definitley have to richen and lean the needles to keep it at this temp /////be sure to keep track of how much you turn each needle and which way you turn it .....with the grp i cant say that you would need to touch the hsn ....just the lsn .....
----after the idle tanks throw it down and run 4 tanks
tank 1 ....1/4 throttle blips no longer than 1 second blips ....then 1/2 throtlle ...then 3/4 throttle ...then full throttle ....temp the engine very frequently every 4-5 passes by you ...and adjust needles to keep temp in your certain range ....
---after that hit the track ....keep a close eye on it for the first 3/4-gallon of fuel ....it will be golden .....it sucks having to do this ...but if you do it will pay dividends down the road .....

here is a link to some of the best info i have ever read on tuning breaking in and some issues that can come up due to a motor not being tuned correctly ....


http://mrcr.ca/Documents/Ron%20Paris...ral%20Tips.htm

ron paris was the man ...his info is top notch ...and works if your stuff is in good running order .....sorry for the long post but theres a right way and a wrong way to do it .....hope this helps :tire::tire:
----

Bigedmond 03-03-2009 05:30 PM


Originally Posted by Frank L (Post 5505303)
What kinda run time are you getting with thatbae pipe in the truggy?

I will normally pit at the 8min mark. I just ordered a 6mm restrictor, as i have been running the 7.5. My epa is set so that it only pulls 75% open for full throttle. And im on gallon 4 for this motor.

[email protected] 03-03-2009 06:09 PM

I am ordering my glow plugs for my non-tuned grp and I was looking at the o'donnell 99 plug. I know I want to try this plug but on the site I will get it from it says it is meant for 30% nitro. Does this mean it will not work with 20 or 25%? Also any other glow plug suggestions would be good.

zixxer 03-03-2009 06:14 PM


Originally Posted by [email protected] (Post 5506260)
I am ordering my glow plugs for my non-tuned grp and I was looking at the o'donnell 99 plug. I know I want to try this plug but on the site I will get it from it says it is meant for 30% nitro. Does this mean it will not work with 20 or 25%? Also any other glow plug suggestions would be good.

you will be fine with that plug ...od plugs are good and they work good in the grp's ..i ran mine 2 weeks ago on 25% gen2 byrons with an od 97t works good lasts long time

[email protected] 03-03-2009 06:18 PM


Originally Posted by zixxer (Post 5506289)
you will be fine with that plug ...od plugs are good and they work good in the grp's ..i ran mine 2 weeks ago on 25% gen2 byrons with an od 97t works good lasts long time


ok great, thanx for the help. I will be using your break in method also!! Do you have the non-tuned version also? How is your power band, bottom, and top?


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