Engine Build

[NINER]

So i have read a bunch of threads and figured out most of what I want to do to my DRZ. My ultimate goal is to make as much or a little bit more than a CRF450, buying parts and going up in power as the money becomes available. Here is my plan:

Step 1-

Vortex airbox with K&N filter (already have)

FCR MX tuned for stock pipe

Step 2-

Above with Yosimura Stainless exhaust

Rejet carb

Step 3-

Athena 94mm big bore kit

Hotcams

Maybe some mild headwork and valve springs

My questions:

Does this sound like a good plan of attack?

Is Athena the best bore kit for the $?

What compression ratio should the big bore kit be. It must run on pump gas.

Will that compression ratio require 93 octane?

What hotcams should I get? From wehat I hear there are stage 1, stage 2, and newer cams that have no stage designation

Is headwork, valves, springs really required? I am looking for 45-50HP.

Anything else that I am forgetting?

[drzrobbcanuck]

don't know what the vortex airbox is, but openning up the air box inlet to 3x3" hole will let it breathe well enough on that end.

The pipe, fcr-mx, hotcams stage 2 intake and no stage or stage 2 exhaust, 94mm bore (either athena or, cheaper/equally good=millenium technologies bore and replate), valve springs for reliability, not for power, and you'll be there. So, yes, good list except for the airbox, which may or may not be.

I haven't had a chance to try out a crf to compare mine to, but I have those mods done to my drz and it rocks.

[Harvey600]

Eddie says the stock head is good for 55hp, so no need to port it, better off going for one piece valves, the stockers are known to break when in a tuned motor. You're looking at 12:1 compression ratio so you can stick to pump gas.

[NINER]

don't know what the vortex airbox is, but openning up the air box inlet to 3x3" hole will let it breathe well enough on that end.

The pipe, fcr-mx, hotcams stage 2 intake and no stage or stage 2 exhaust, 94mm bore (either athena or, cheaper/equally good=millenium technologies bore and replate), valve springs for reliability, not for power, and you'll be there. So, yes, good list except for the airbox, which may or may not be.

I haven't had a chance to try out a crf to compare mine to, but I have those mods done to my drz and it rocks.

The vortex airbox is an aluminum airbox that is basically like doing a 4x4 mod instead of a 3x3 mod. I don't know if the extra airflow CAPABILITY is really needed, but I got it cheap for around the price that I would have paid for a K&N filter and it looks cool.?

Eddie says the stock head is good for 55hp, so no need to port it, better off going for one piece valves, the stockers are known to break when in a tuned motor. You're looking at 12:1 compression ratio so you can stick to pump gas.

12:1 runs on 93 or can 89 or 87 be used?

So stage 2 hot cams, some ferrea valves, and some nice valve springs to make sure the cams don't beat them up too bad and I am good.?

[Wayward Son]

you can spend the money much better than on the the vortex air box.

either way,a stock crf 450 makes 50hp.

what you have planned is 48hp or so.

[NINER]

you can spend the money much better than on the the vortex air box.

either way,a stock crf 450 makes 50hp.

what you have planned is 48hp or so.

I only paid about $90 shipped for it with the filter, so it didn't break the bank by any means.

Within 2 HP is close enough for me. Just looking for the most economical, reliable, daily rideable combo possible.?

[Harvey600]

My GSXR track bike runs on 89 or 93, with no problems, so the DRZ shouldn't have a problem with it.

[Captain Uno]

Those are good mods. Basically the same I have on my Z400 and what I plan to do with my DRZ.

I would recommend WEbcams over the stage 1 hotcams. If you can find some stage 2's go for that.

Here are my mods on my Z400, and it runs like a beast. The webcams that I have have a lower end powerband, that is what I like for trails. If you want a bit higher like the stage 2 hotcams, they have them. Webcams makes great products at a good price.

Athena 434 kit (12.2:1 compression ratio piston), Single layer base gasket, Ferrea Stainless Valves, Dyna NP ignition, FCR 39mm carb(170 Main, 45 Pilot, 35 Leak, Needle 3rd clip, 2 turns on fuel screw), Pro Circuit Adjustable Fuel Screw, Raptor 660 petcock, Yuasa 200 CCA battery, ESR Coolant Temp Guage, DRZe Valve Springs, DID 3/4 timing chain, Webcams grind 293/536, Yoshi RS3 Full System, ESR Intake with "Outer Wear", ZipnZ's splash guard, TT MCCT, and RTC Radiator Scoops & Louvers

[andersoncol]

where do you find these "webcams"?

[Captain Uno]

where do you find these "webcams"?

http://www.webcamshafts.com/

[hi_im_sean]

My GSXR track bike runs on 89 or 93, with no problems, so the DRZ shouldn't have a problem with it.

that has nothing to do with anything??????????

the static compression ratio wont quite tell if it will ping or not (although it may be plenty close enough in a drz motor, mi just not sure). the dynamic compression ratio is more important, deepnds on your cam choice as well. i know in a small block chevy you can change the DCR quite a bit by cam selection and cam timing, while keeping a constant SCR.

eddie is there enough differences in DRZ cams to change the DRC enough to matter. do they publish duration at 0.050 lift or at 0.006 lift , or both like a small block, or neither?

[William1]

RHC 187's (WebCams) are measured at .050" lift with zero clearance.

[MotoChris521]

I only paid about $90 shipped for it with the filter, so it didn't break the bank by any means.

Within 2 HP is close enough for me. Just looking for the most economical, reliable, daily rideable combo possible.?

Now if you knew the jetting specs for a "4x4" mod....

[Harvey600]

that has nothing to do with anything??????????

the static compression ratio wont quite tell if it will ping or not (although it may be plenty close enough in a drz motor, mi just not sure). the dynamic compression ratio is more important, deepnds on your cam choice as well. i know in a small block chevy you can change the DCR quite a bit by cam selection and cam timing, while keeping a constant SCR.

eddie is there enough differences in DRZ cams to change the DRC enough to matter. do they publish duration at 0.050 lift or at 0.006 lift , or both like a small block, or neither?

It has race cams and 13:1 compression, running a ported head and full race exhaust, it's probably running a higher state of tune than the spec for this guys motor and it runs fine. Although whether the differences between a single or a multi are enough to make a difference, I do not know. I've built car and bike engines and never had any problems.

We get a choice of 98 or 95 RON, some pumps have 99, but, only a few that I've noticed recently.

[MutualBill]

Now if you knew the jetting specs for a "4x4" mod....?

You need very little...if any tweaking for the larger hole Vs the jetting specs for the 3x3 hole.

My entire airbox top is gone...just like the DRZ475TT bike. Adjusting my jetting was not that hard using the guidelines offered on this site. Just do a little searching.

[hi_im_sean]

It has race cams and 13:1 compression, running a ported head and full race exhaust, it's probably running a higher state of tune than the spec for this guys motor and it runs fine. Although whether the differences between a single or a multi are enough to make a difference, I do not know. I've built car and bike engines and never had any problems.

We get a choice of 98 or 95 RON, some pumps have 99, but, only a few that I've noticed recently.

ahhh, ok. now that pertains to the conversation. i wish we could get 93, let alone 95, 98, 99, you guys are lucky

[Harvey600]

Perhaps I should have listed the mods to the bike in my original post, so it can be seen to be more relevent to the question asked, but, I didn't want to go on about my GSXR when this is a DRZ forum!

I've not been to the states, but, I have heard your gas isn't that great, (is this true?) I guess we're pretty fortunate to have a higher octane rating. I'm sure the static ratio on even my stock GSXR is something like 12.5:1.