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

Bigedmond 12-09-2008 07:31 PM

i am happy with the bottom of the .21 i have in the truggy. 1 more day, and i will be on my second piston and sleeve for the buggy. almost 9 gallons, I'm happy with it. Also get to see if TKO ceramics will give it anymore power.

Djballen 12-09-2008 08:27 PM

delete

bherzog513 12-09-2008 09:02 PM

My GRP has does not produce bottom end poop. Anything I suspect produces poop, I would figure to be from/on bottom end, but I personally see nothing in the form of poop being useful on the racetrack.(being a smart a$$:lol:)

fiveoboy01 12-10-2008 07:32 AM

I dunno, the two guys in my club who run the GRP .21(one in a MBX5T and the other in an 8IGHT-T) do nothing but dominate everyone every weekend. Their trucks seem to have plenty of bottom end.

I had a JPX .28 in my jammin truggy, one time myself and one of them exited the last turn to a very long straight and we were dead even the entire time. Maybe something was wrong with your motor even.


Originally Posted by Bigedmond (Post 5144517)
The GRP engine tool set is the best thing ever. 5 minutes and the motor was completely torn down, and bearings removed.

Anyone know where I can get this tool set? Haven't seen it for sale anywhere.

ABURTON 12-10-2008 07:37 AM

http://www.carolinasrc.com/Webstore/...dproduct=10023


It will make it to ya before the weekend. Let me see if I have some discount codes in any of my emails....

ABURTON 12-10-2008 07:40 AM

desert...

The guy wanting the carb has not gotten back to me.


I would like to see the idle screw and it's location though..

If ya can post a pic on here.

ABURTON 12-10-2008 07:46 AM

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desertbird 12-10-2008 05:01 PM

1 Attachment(s)
here's a pic of the carb.

ABURTON 12-10-2008 07:55 PM

thanks;)

I was wanting to look at your idle screw setting. Thats cool...

desertbird 12-11-2008 05:37 AM


Originally Posted by ABURTON (Post 5152977)
thanks;)

I was wanting to look at your idle screw setting. Thats cool...

Oh, well you can barely see it in there. I could have told you how many turns:confused: close to 4. What are you thinking?

ABURTON 12-11-2008 07:10 AM

4 turns out from closed or 4 turns in?

Not saying this is the case with you but a lot of guys tune the engine good or atleast it runs without flaming. It runs good and makes decent power, gets ok runtime. In the end life is cut short and the motor is not at it;s full potential because it's tuned with a "rich" bottom needle and a "lean" top needle, not the way this engine was designed to run.

So, it's easy to just look at the idle screw...if it's ran a pretty good ways in you know they got a rich bottom. If it's out pretty close to the outside(approx 2mm from flush), then you know the bottom was set correct. Or close.

I see all the time guys who say they are awesome and running 240. I know the engine is flip flopped with the needles. I have never seen a properly tuned one run over 200-205, with most cases being about 190 ish.

It's not a hard to tune engine, it's not finicky, once tuned I very rarely ever turn needles. Not all motors tune the same. So I think some guys get used to a vspec and then try there best to make this engine sound and tune like that.

Again, this may not be the case with you, just an observation on my part in the past;)

Bigedmond 12-11-2008 07:44 AM

I have to agree 110%. I see guys here that have always ran nova, vzb, or RB and think that the motor has to get around 230. I dont know how many times i have came in after a 10 minute qualifer and have my pit guy say 180, and drivers around me saying its to rich on the way down the ramp. This becomes funny because i normally am in the top 3 of my classes.

1 driver here was always running his GRP around 240, and i asked him to let me tune it. I got his temps around 190, and he said it had more power then it ever had.

desertbird 12-11-2008 07:51 AM

About 4 turns out form closed. 2mm from flush sounds about where it was. LSN was 5.75 out from closed with the slide pulled out.

Yeah always ran 185 to 195 after I learned in the very beginning this motor's massive head deceives the temp. I also learned it would flame with a rich bottom, and would let you lean it out to a sick lean bog on top before I got to 240 temp range. I never had to move the needles more than 4 hours. More like 2 max either way.

Not sure why the bottom of the piston litterally fell off, but it did.

NDHotbodies 12-11-2008 05:13 PM

I'm glad I see others had those engine temps, 180/190.. my GRP .21 in my PE ran those temps all summer and ran great also.. took two 1sts, and two 2nds and 2nd for the season. 5 race season..

zixxer 12-11-2008 05:45 PM


Originally Posted by ABURTON (Post 5154432)
4 turns out from closed or 4 turns in?

Not saying this is the case with you but a lot of guys tune the engine good or atleast it runs without flaming. It runs good and makes decent power, gets ok runtime. In the end life is cut short and the motor is not at it;s full potential because it's tuned with a "rich" bottom needle and a "lean" top needle, not the way this engine was designed to run.

So, it's easy to just look at the idle screw...if it's ran a pretty good ways in you know they got a rich bottom. If it's out pretty close to the outside(approx 2mm from flush), then you know the bottom was set correct. Or close.

I see all the time guys who say they are awesome and running 240. I know the engine is flip flopped with the needles. I have never seen a properly tuned one run over 200-205, with most cases being about 190 ish.

It's not a hard to tune engine, it's not finicky, once tuned I very rarely ever turn needles. Not all motors tune the same. So I think some guys get used to a vspec and then try there best to make this engine sound and tune like that.

Again, this may not be the case with you, just an observation on my part in the past;)

alan the stock needle (lsn) setting looks super rich as you had told me ...what would would be a good starting point if im breaking the motor in on the lsn ....how many turns out from bottom ...or how many turns in from flush ...stock it looks like it will take 3 full turns to get it flush ....thanks v.i.p.


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