Cam and Piston

[tcr450r]

Just recently I made a post about what piston I should get that I can use with pump gas. Well, I am debating on maybe just running a 50/50 mix and I was also thinking about the Sparks Aggresive drop in cam for a camshaft mod. I was wondering if that cam is any good, as I haven't really heard much about it, is it for top end or low and will it go good with the Standard Bore Sparks JE 13.8:1. From what I have heard, you can run this piston with 50/50 mix. Correct me if I am wrong.

[cals400ex]

the cam you run will have a lot to do with what octane fuel is needed. what kind of riding are you interested in? the hrc cam is an aggressive drop in cam with most of the gains from mid-top end. the stage 2 hotcam shines in the mid range. you won't suffer low end power with this cam but it won't give quite as much top end. however, there is still a nice gain over stock top end. i wouldn't get the sparks cam. you will just pay more for it. you can get the crf cam. some people who run a cam with a lot of overlap (like the hrc and more aggressive cams) can get away with running near 13:1 compression on fresh 93 octane fuel. you could also thermal coat the piston and help things out. i wouldn't run the 13.8:1 on pump gas though.

Originally posted by cals400ex
the cam you run will have a lot to do with what octane fuel is needed. what kind of riding are you interested in? the hrc cam is an aggressive drop in cam with most of the gains from mid-top end. the stage 2 hotcam shines in the mid range. you won't suffer low end power with this cam but it won't give quite as much top end. however, there is still a nice gain over stock top end. i wouldn't get the sparks cam. you will just pay more for it. you can get the crf cam. some people who run a cam with a lot of overlap (like the hrc and more aggressive cams) can get away with running near 13:1 compression on fresh 93 octane fuel. you could also thermal coat the piston and help things out. i wouldn't run the 13.8:1 on pump gas though.

yep, what he said :macho

[tcr450r]

So do you guys think I should go with the hrc and a 13:1 piston and try to run 93 octane gas? And does sparks cell a 13:1 piston. I was on their website earlier and I dont remember seeing one. If not, what about wiseco. If not please mention some. By the way, I ride mx.

Originally posted by tcr450r
So do you guys think I should go with the hrc and a 13:1 piston and try to run 93 octane gas? And does sparks cell a 13:1 piston. I was on their website earlier and I dont remember seeing one. If not, what about wiseco. If not please mention some. By the way, I ride mx.

sparks sells only a 13.8:1 piston, any compression below that they edit the 13.8:1 and create the lower compression, so you can get any, if i was you id go with either the hrc or stg 2 hotcam and a 12.5:1

[cals400ex]

yep, either the hrc or stage 2 should be good. if you need more low end power you might want to consider some others. by adding a pipe, hrc, and modded air box lid i actually gained low end power over stock.

[tcr450r]

Originally posted by cals400ex
the cam you run will have a lot to do with what octane fuel is needed. what kind of riding are you interested in? the hrc cam is an aggressive drop in cam with most of the gains from mid-top end. the stage 2 hotcam shines in the mid range. you won't suffer low end power with this cam but it won't give quite as much top end. however, there is still a nice gain over stock top end. i wouldn't get the sparks cam. you will just pay more for it. you can get the crf cam. some people who run a cam with a lot of overlap (like the hrc and more aggressive cams) can get away with running near 13:1 compression on fresh 93 octane fuel. you could also thermal coat the piston and help things out. i wouldn't run the 13.8:1 on pump gas though.

Who makes that the 13:1 compression piston that you said I might be able to get away with 93 octane fuel?

I think I am going to go with the hrc, does anyone know where I can get it just by itself without the hrc kit? Thanks for the help with the cam, I just can't decide on the piston.

Originally posted by tcr450r
Who makes that the 13:1 compression piston that you said I might be able to get away with 93 octane fuel?

I think I am going to go with the hrc, does anyone know where I can get it just by itself without the hrc kit? Thanks for the help with the cam, I just can't decide on the piston.

sparks, www.servicehonda.com

[tcr450r]

alright thanx for the link, but what if the 93 octane doesnt work, whats the worst i would have to do, just run a mix?

[cals400ex]

if you just want to be 100% safe, you could just get a piston around 12:1. its sounds like you are worrying about the gas a lot. you would not need to run straight race gas with 13:1 with an aggressive cam. some may recommend it, but there is no way i would.

Originally posted by tcr450r
alright thanx for the link, but what if the 93 octane doesnt work, whats the worst i would have to do, just run a mix?

yep

[tcr450r]

say if i do get this 13:1 and i try 93 octane in it, is it just either going to run like normal or not run at all, what im trying to say is if 93 octane isnt going to work, what are the signs and would it cause any engine damage.

[mikes450r]

i think you really need to consider what your doing here..i think you are really going to be pushing it with a 13:1 and 93 octane..and also you would have to make sure you ran fresh 93 only...no old ****...that can be a pain in the *****..

if you want to be safe you should just go with a 12:1 piston..

also how come you just dont run race fuel..

mike

[tcr450r]

well i am willing to run a 50/50 mix, but when he mentioned that i might be able to get away with 93 octane i figured i would try and take what i could get. But no, i dont mind running a mix. I just want to get the most power out of it.

[cals400ex]

more compression should definately yield more power. but it comes at a cost.......you may need race fuel. it will be hard to tell if you need race gas or not. you may notice some pinging, etc. you would need to make sure it isn't lean, especially if you try to run around 13:1.

[tcr450r]

Alright guys, thanks for helpin me out. I am still debating between the 12:1 and the 13:1 but atleast I got an understanding. Right know I am leaning towards the 13:1 just for power, and if I got that I would just start out, and always run, a 50/50 mix just to be safe. I am positive on the hrc, I just need to try and find it without the kit. I know that the HRC isn't mainly for low end, but I have a set of 18's on so those should make up for the low end. If you have any links to the hrc cam by itself please post them. Thanks for all the help.

[cals400ex]

here is a list of part numbers for the parts that come in the kit:

http://www.trx450r.org/forum/index.php?showtopic=4996

you can copy the part number and buy it from www.servicehonda.com

if you are a member at www.trx450r.org you can buy just the cam from woodward specialities for the best price that is known to man kind :D

[trost66]

If i was you I would just I would just buy the cam. Take your airbox lid off and rejet the carb. You Don't need all that other stuff in the kit. Also go with the 13-1 piston

[mstrav1]

you can run the 12.0-1 and the hrc on 91 pump. that is the max comp you can go period!!!!!!!

if you live in a place that has 100 octane at the pump like i do in vegas you could run the 13.0-1 piston (4.39 per gallon not to bad)

if you are trying to cut it close you will just burn up your motor.

you don't mention what you are trying to achieve? maybe a big bore kit 480 / 510 / 520 or ? might be better for what you are trying to do with a stock bore piston. you need to think it through and do it right the first time or your wasting money. what head work you going to do? i can go on all day but you need to really get us more info and go from there. as it stands you are real wishy washy and we havn't even brought up carb and jetting yet!!!!!!

[tcr450r]

Well, if it were up to me, I would already have a big bore kit in it. But my dad forbids it. He thinks that if I do something like that then I will have no reliability in my motor and that i am just wasting my money. But me, I am just looking for more power and speed. If you guys don't think that going with a cam and a piston isn't a good idea then please tell me what you think I should invest in. I do not have any motor work done to it yet. The only power mods I have is the pipe, filter, airbox and it is jetted as it shows in my signature.

[D-7#61-450r]

Why are you so worried about running 110 octane. Your quad will have increased power, it will run cooler, and compared to todays gas prices its not really all that expensive. Your looking for power but your trying to be cheap about it. That doesn't work! A little hint buy a crf 450 cam off ebay. You can find one for around $50. Its more agressive than an hrc and from what people say it was what sparks used to sell for $200. By that I mean same profile not that very cam. Hope you find this somewhat usefull.

[mstrav1]

110 doesn't make more power!!!! it alows you to utilise power you are making from advanced timing and high comp pistons without causing pinging / or destoying the piston!!!!

110 = waste unless you have a 13.5-1 piston

the only fuel you will se more power from is oxgenated vpu4!!! you gain about 6% only after you raise your main 1 size. not by just running this fuel, down side is it leaves build up in carb / cylinder!!!!

just by 91 octane and a piston under 12.0-1 and you don't need to worry about it $2.45 is wayyyyy cheaper than $8-$10 per gallon for 110!!!!!!!!!!!!!!!!!!!!!!!!

[D-7#61-450r]

I am running 13.5 to 1.
And you guys must be getting screwed on 110. Here in Va. its only $5.00 a gallon. 114 is $8.00. Not that big of a price deal for me on the 110 thats the reason I'm ruunig it, also price doesn't vary like 93 octane.