Will I be okay?

[400exmxrider15]

Getting a JE High Comp 12.5:1 piston installed next week, running RACE gas 110 oct. Question is, do i need to be jetted with using 110 and having a high comp? Also, Is it a good idea to get the head and cylinder bead blasted?

[PaRedneckRiders]

if your running 110 then yes jet it to where it runs best with 110.
Are you talking about the outside of the head and cylinder or actually inside the sleeve?? Where the piston would be haha

[400exmxrider15]

Originally posted by PaRedneckRiders
if your running 110 then yes jet it to where it runs best with 110.
Are you talking about the outside of the head and cylinder or actually inside the sleeve?? Where the piston would be haha

Yes, obviously outside. lol. I think it would look 100% cleaner that it does now...

[400exmxrider15]

Do I have to run full 110, or can I mix? Its $5 a gallon here for 110, while $3.19 for 93 pump gas.

[tri5ron]

I notice you've got 3 different types of graphics, your grips, and block-off plate, ...
Your bumper, nerfbars, tires, and throttle cover,...
listed in you sig, but not much in the way of engine mods.

Before you get this 12.5:1 piston installed,
you'd better think seriously about having your studs replaced / upgraded by GTT, or your going to be back here very soon asking why you are blowing head gaskets, and leaking oil.

Many other members here, have learned the hard way, and have shared their experiences in the effort to save others from having to deal with the same difficult and expensive issues.

Do it right the first time, or pay triple to have it done right later.

Gee,... I hope I didn't "Sugar-coat" that too much :blah: :D

[400exmxrider15]

Originally posted by tri5ron
I notice you've got 3 different types of graphics, your grips, and block-off plate, ...
Your bumper, nerfbars, tires, and throttle cover,...
listed in you sig, but not much in the way of engine mods.

Before you get this 12.5:1 piston installed,
you'd better think seriously about having your studs replaced / upgraded by GTT, or your going to be back here very soon asking why you are blowing head gaskets, and leaking oil.

Many other members here, have learned the hard way, and have shared their experiences in the effort to save others from having to deal with the same difficult and expensive issues.

Do it right the first time, or pay triple to have it done right later.

Gee,... I hope I didn't "Sugar-coat" that too much :blah: :D

What do you mean by 3 different types??? Cant I just order new studs from GTT and have my machine shop install them????

[CJM]

He was poking some fun at you.

Do the GT Thunder studs, having them install them insures they are done correct as they all dont stick out the same lengths and the machine shop might not do it right..

[400exmxrider15]

So I have to send my cylinder all the way to there shop!!! What is there turn round time?

[tri5ron]

Originally posted by CJM
He was poking some fun at you.

Do the GT Thunder studs, having them install them insures they are done correct as they all dont stick out the same lengths and the machine shop might not do it right.. CJM is Correct, as well as, they need to be Roll Formed threads, as opposed to Tap Cut Threads. (yes, it makes a difference).

[400exmxrider15]

I dont see why I can't take this to my local machine shop. They build sprint car motors and ARCA motors...If i just tell them I want them installed, they can do it? I can give them strict instructions? I just hate dealing with shipping...

[tri5ron]

We can only give you the advise, knowledge, and personal experiences, that you came here to recieve.

GTT is intimately familiar with this particular process, this particular installation, on this particular engine, with it's particular materials, issues, and characteristics.
It's what they do for a living.

It's your money.
You can spend it wherever you choose.
Just choose Wise-ly, so that you don't have to choose Twice-ly.

[trailrider894]

Originally posted by tri5ron
We can only give you the advise, knowledge, and personal experiences, that you came here to recieve.

GTT is intimately familiar with this particular process, this particular installation, on this particular engine, with it's particular materials, issues, and characteristics.
It's what they do for a living.

It's your money.
You can spend it wherever you choose.
Just choose Wise-ly, so that you don't have to choose Twice-ly.

GTT designed the studs, So just like Ron said, there is no better person to install them than the man himself.

[400exmxrider15]

Originally posted by trailrider894
GTT designed the studs, So just like Ron said, there is no better person to install them than the man himself.

Great points guys.

Looks like I'm getting:
Je High Comp 12.5:1
Cometic EST Kit
GTT Heavy Duty Stud Kit
hone


Anything I'm leaving out needed fra top end rebuild?

[trailrider894]

Originally posted by 400exmxrider15
Great points guys.

Looks like I'm getting:
Je High Comp 12.5:1
Cometic EST Kit
GTT Heavy Duty Stud Kit
hone


Anything I'm leaving out needed fra top end rebuild?

I would get a CRF timing chain just for assurance. Make sure to check your valve springs also.

[tri5ron]

Originally posted by trailrider894
I would get a CRF timing chain just for assurance. Make sure to check your valve springs also. True That.

Also don't forget that you will now be creating a considerably greater amount of heat.

You need to get rid of that heat.

Your stock oil cooler will not be suffecient by itself.

You will need to increase the cooling capacity of your machine accordingly, equal or greater to the amount of increased heat it will be producing.

This means you would be Wise to start using the search function, and learning everything you can on oil coolers, spal fans, increased capacity tanks, rerouted oil to the head, etc.
There are countless threads covering this subject.

Remember, the more you research and learn about your machine,...
The more chance you have of holding onto some of your cash.

Trust us,
The "School of Hard Knocks", and "College of Experience" has a VERY high Tuition.

You can earn some "Scholalship" to those lessons, by researching these subjects and threads.

[sneaky11]

be sure to get your head stud installed before your honing process... or you gonna have tight spot in the cylinder and probably GT will tell you that... with this kind of compression, you will also to change your cam cuz you gonna build to much dynamic compression with the oem cam and BTU's probably gonna sit to long in the chamber, you will need to run higher octan gaz to not predetonate... prefire = hard time for your rod... that is surely something you want to avoid with a fresh new built!!! I suggest you looking for stg2 hotcam(this is a drop-in cam), webcam 450/451 and GT thunder have a cam with the same shape of the web cam I speak of... that is for a 416 or less with the last 2 you will need hardfaced rocker arms for $$$ure.

I'm in the same rebuilt process with a CP 12.5:1 416... and I'm looking to build something that I'll run with around 100 octan... if I can help you with my exriders.com search engin knowledges... :eek2:

[400exmxrider15]

So now, I'm hearing that a 12.5:1 compression isnt a true 12.5:1....(stock bore) What this mean????

[400exmxrider15]

I just replaced my timing chain at christmas, not but 2 hours on it...

[CJM]

Originally posted by 400exmxrider15
I just replaced my timing chain at christmas, not but 2 hours on it...

A stock chain is ok, but you must understand a CRF chain is MUCH stronger and will stretch and wear out less overtime.

So its always good to do the chain, guides and auto tensioner all at once to be sure everything holds up. Chain stretches, slips a tooth and your gonna have bent valves

[tri5ron]

go back and re-read all the suggestions you have already gotten.

you can not just drop a 12.5:1 piston into a otherwise stock engine, and have it run correctly.
10.5:1 ,....yes, (with some minor tuning/jetting)

12.5:1 ,....No. ( it will need many other components addressed, to accomodate, and compensate, for that high of compression)

The fact that you are not getting the FULL amount of the "Advertised" compression is irrelevant.
That has more to do with the pistons deck height at TDC, which is another subject entirely.

[400exmxrider15]

So i Have to have a crf chain with tensioner and guides!!?!? Do i need a cam for that high comp????I will be running pure 110 (Renegade) I dont understand what i need??HD studs are going in too!?!?

[CJM]

What you need is the following to make it all work properly together.

Heres what I would do:
12:5:1 piston
Stage 2 or 3 hotcam
CRF chain and components
Jetting
full or at least a slip one exhaust.
Bore job, say 416 or 426

You also need to run at least 100 octane, have better cooling like a spal fan, a bigger oil cooler, bigger oil tank etc. The cam is needed cause in order to take advantage of the compression you nee the valves to stay open longer as well.

The reason most do not run higher than 11:1 pistons is b/c of the heat created. The EX doesnt like heat, its air cooled unlike alot of the more recent liquid cooled quads. It generates alot of heat when you up the compression that much and its hard to dissipate the heat.

What are you really looking to get out of it? Keeping up with a 450, being the fastest guy out there? Or just the bragging rights?

In all honesty it sounds to me like you would be much better off buying a 450r. It will have the performance you want, with the liquid cooling-which means you can up the compression quite a bit and still be ok.

[400exmxrider15]

Originally posted by CJM
What you need is the following to make it all work properly together.

Heres what I would do:
12:5:1 piston
Stage 2 or 3 hotcam
CRF chain and components
Jetting
full or at least a slip one exhaust.

You also need to run at least 100 octane, have better cooling like a spal fan, a bigger oil cooler, bigger oil tank etc. The cam is needed cause in order to take advantage of the compression you nee the valves to stay open longer as well.

The reason most do not run higher than 11:1 pistons is b/c of the heat created. The EX doesnt like heat, its air cooled unlike alot of the more recent liquid cooled quads. It generates alot of heat when you up the compression that much and its hard to dissipate the heat.

What are you really looking to get out of it? Keeping up with a 450, being the fastest guy out there? Or just the bragging rights?

In all honesty it sounds to me like you would be much better off buying a 450r. It will have the performance you want, with the liquid cooling-which means you can up the compression quite a bit and still be ok.

I do not want to be able to run with 450 class, but i do wish to have a little bit more bottom end and faster revving. If a 11:1 is gonna make a big difference from stock, i'll go that route, for now though, i dont have money for all that...

[CJM]

Then what you want to do is either an 11:1 or 10:1 and a cam.

However, if you dont have the cash to do all the mods it might be a better idea to wait till you have the cash and build it right once and for all.

In order to get everything running tip top and make the machine quite a bit faster you need about 600-700 bucks to do it right.

Piston $100
Bore job and HD studs: $175
Cam: $150
Gaskets $50-75
Timing chain, tensioner, chain guides $150
Jetting: $50

Trust me, if you build a 416 or 426 kit following this model you will easily keep up or even beat the 450rs and have ALOT of power. The above is pretty much my setup (minus exhaust), a stock 400 cannot touch me, a slightly modified one cant touch me, a 450r can beat me but only with a good rider. I have no issues keeping up with them or beating them if they dont know how to handle the machine.

[400exmxrider15]

The class im running though is Youth 400 or less...So I dont wanna get caught with cheating going with a bigger bore..My 400 is also not running as of now, the cylinder has stripped studs, piston is new, but needs re-ringed, i figured while im in the motor, i might as well replace it with a high comp. I dont care for getting a cam right now, I will get a cam after i get done with my suspension (revalved triple rate 450r shocks)..

[CJM]

Ok, then I think you would best benefit from asking GT thunder to deck the cylinder a bit to get that last little bit of compression you want or do like mickey dunlop and use an XR400 gasket. The cam will help, but not much b/c of the stock bore.

Not much else you can do if your limited to the 400cc class.

[tri5ron]

Originally posted by 400exmxrider15
I do not want to be able to run with 450 class, but i do wish to have a little bit more bottom end and faster revving. If a 11:1 is gonna make a big difference from stock, i'll go that route, for now though, i dont have money for all that... http://i111.photobucket.com/albums/n148/tri5ron/Emoticons%20and%20funny%20pics/barniearrgh.gif I think my work is done here
http://i111.photobucket.com/albums/n148/tri5ron/Emoticons%20and%20funny%20pics/bangheadonwall.gif

[400exmxrider15]

Sorry guys for all the confusion, I'm used to building Blasters..i raced those for 2 years and quit cause i went through too many top ends

[trailrider894]

Originally posted by tri5ron
http://i111.photobucket.com/albums/n148/tri5ron/Emoticons%20and%20funny%20pics/barniearrgh.gif I think my work is done here
http://i111.photobucket.com/albums/n148/tri5ron/Emoticons%20and%20funny%20pics/bangheadonwall.gif

Sure did miss you ron!!!!!!!!

[tri5ron]

Originally posted by trailrider894
Sure did miss you ron!!!!!!!! I belive that Density, and Rate of Absorbtion, and directly proportional.
whether they be in Physical, or Comprehensive form.

[trailrider894]

Originally posted by tri5ron
I belive that Density, and Rate of Absorbtion, and directly proportional.
whether they be in Physical, or Comprehensive form.

:huh

2 hours of lecture on women creating make believe families in prison, i have been brain dead ever since........... Maybe this college to be a cop thing isn't worth it... They pay isn't much better with a degree anyway.... :huh

[tri5ron]

trailrider,
it was intended as sarcastic humor, (not directed at you). :devil:

[trailrider894]

Originally posted by tri5ron
trailrider,
it was intended as sarcastic humor, (not directed at you). :devil:

Ha ha i know. lol just venting... :blah:

[tri5ron]

Originally posted by trailrider894
Ha ha i know. lol just venting... :blah: Hahaha,.. you had me at,...

"2 hour Lecture on Women..."


You could have just stopped right there ! LOL !

NOBODY could have survived that ,with ANY level of Comprehension !

http://i111.photobucket.com/albums/n148/tri5ron/Emoticons%20and%20funny%20pics/lmaosmiley.gif

[trailrider894]

Originally posted by tri5ron
Hahaha,.. you had me at,...

"2 hour Lecture on Women..."


You could have just stopped right there ! LOL !

NOBODY could have survived that ,with ANY level of Comprehension !

http://i111.photobucket.com/albums/n148/tri5ron/Emoticons%20and%20funny%20pics/lmaosmiley.gif

yeah.... a 2 second lecture has me running for the hills!!!

[400exmxrider15]

Okay, So I will get a Wiseco 11:1 High Comp piston, GTT HD Studs, Cometic EST Gasket Kit.....How much can I mill the head and be safe??

[sneaky11]

don't touch your head, the cometic gasket is tinner then oem , that will get you amlost at it... put your money on a cam, if you got stock bore, go with the stage 1 or if you can find an XR cam for cheap I think that can be a better choice...

you can also put a sparks timing key with that, that gonna help you build a little bit more compression. THAT WILL HELP ALOT!! 25$

If you race MX, get your flywheel shaved... THAT WILL HELP ALOT!! 50$ maybe

If you are a little bit handy, you can smooth your head ports and polish the exhaust one... THAT WILL HELP ALOT!! Priceless

For everything else, there's MasterCard!!
:scary:

[trailrider894]

Originally posted by 400exmxrider15
Okay, So I will get a Wiseco 11:1 High Comp piston, GTT HD Studs, Cometic EST Gasket Kit.....How much can I mill the head and be safe??


GTThunder will know how much is safe.

[400exmxrider15]

For now, I will go stock bore, 11:1 compression piston (wiseco), Gt thunder head studs, cometic est gaskets, and possibly take my dremel and polish those exhaust ports.

I will save up for a cam after i get the suspension work done