Jump to content

Web cam 89 with stock piston?

Recommended Posts

If you are going to install a cam you might as well install a good piston.

 

In my opinion the 89a is way too big/long for the stock piston and CR.

Edited by VortecCPI

Share this post


Link to post
Share on other sites

If you are going to install a cam you might as well install a good piston.

 

In my opinion the 89a is way too big/long for the stock piston and CR.

Finally a not going without the other!

Share this post


Link to post
Share on other sites

If you are going to install a cam you might as well install a good piston.

 

In my opinion the 89a is way too big/long for the stock piston and CR.

By the way what do you think about wich is the best piston Wiseco.Wossner,BBr for,compression lighter,qualities,price?

Share this post


Link to post
Share on other sites

IMO:

Compression is the single and most largest bang for the buck. The more the better.

(Wossner or Wiesco)

Second...Larger diameter header pipe.

(FMF or XR's only)

Proper camshaft (closest your desired needs) would be the third largest bang for the buck. (I like Web, 40mc/402 the best for a stocker)

Fourth priority would be properly porting the intake port correctly.

After that:

Larger size piston (big bore)

Larger stroke (stroker crank)

Larger carb. 28mm-30mm

EO reverse cone exhaust system.

Terry Miller would be a great source for all of the "largest smile" producing products above.

541-923-1290

Frank at Engines Only

(Xr100.com) would be another good source.

  • Like 3

Share this post


Link to post
Share on other sites

I did a Web 40mc/402 and Wiseco piston for ~$300.  Absolutely huge bang for the buck.

 

Oversize head pipe is A MUST even with the stock engine.  According to findings here in TT the CR with either Wiseco or Wossner is still miserably low and barely 10:1.  Wiseco is about half the price so that was my choice.

 

My mildly-modified CRF230 is everything I could ever ask for and the engine is simply amazing for what it is.

  • Like 3

Share this post


Link to post
Share on other sites

 If I might jump in here, who makes the oversized header and does it fit on the stock tail section?

Share this post


Link to post
Share on other sites

If I might jump in here, who makes the oversized header and does it fit on the stock tail section?

See post #5

Yes, they both fit the stock factory muffler.

Share this post


Link to post
Share on other sites

Ok first mods 120 main pilot 45 and web cam 89a with STOCK piston good idea bad idea?.What kind of performance it would

give it's?230 tuner i await your

comments!

It's a step in the right direction.

All change I have made to my 230 have been incremental with no I'll effect.

I started with12:1 piston. A year later an 89a cam. Year later forks. On and on...

Yes full effect of cam may not be seen till compression is raised but 200.00 a year is much easier than 400 at once..

Share this post


Link to post
Share on other sites

A big/long cam like the 89a will LOWER low-speed cylinder pressure (and power) with a stock piston.  Might be okay for fast long open work but certainly not for slow short tight work.  While the 89a cam is certainly not a wild cam is is certainly not a torquer like the 40mc/402.

 

89a - Power later in torque curve so shift later - Gear selection more critical - Fast long open work

40mc/402 - Power earlier in torque curve so shift sooner- Gear selection less critical - Slow short tight work

 

Example:  An old L-48 350 ci 8.5:1 Chevy can make more net area under the torque curve with a short/small modern cam versus a lazy stock cam, all other engine pieces being equal.  Slap in a big/long cam and you sacrifice power just about everywhere and lose net area under the torque curve.  Though the engine may make more Peak HP overall power is down and you have a real beater.

 

If the CRF230 was already 10:1 like the XR200 or XR250 it would be okay but at 8.5:1 it is not a good idea.

 

Also keep in mind the 89a is not a true "Drop-In" cam like the 40mc/402 cam.

Edited by VortecCPI

Share this post


Link to post
Share on other sites

Either wiseco or Wossner are good choices. Advantage on Wossner is a 67mm is commonly available and increases CC's a bit. Use a .020 headgasket and now in mid 10's for compression which is perfect for pumpgas. That being said the 40-402 is great trail cam. Worked out a few others that fit in between anddifferent "type" of power. As far as 89a here is my impressions.

   After flow testing 2 stock heads as they come from Honda. They stop gaining airflow at around 250-275 valve lift. Not good. The exhaust matches or beats the intake flow throughout range. Not good. Any cam with over .300 lift on stock head is just excercizing valvesprings!!!!  Good thing is with just a little work on intake the numbers jump. Bowl, throat, 3 angle or more and a little work on side of guide boss are all flow increases. Exhaust just lightly clean and do a good valvejob no real porting needed unless building a real hot-rod (then you really need to do some serious porting on intake side). Now with a ported head and at least 10.5 compression the 89 will start to work better. Yet there are cams that will easily out torque it in the trails. As a side note I can have lobe centers altered on 89a cams to change powerband 

Share this post


Link to post
Share on other sites

For some good feedback on 89a versus 40mc/402 PM FrickinJim.  He recently switched from 89a to 40mc/402.  He is very happy.

 

And I DID forget to mention Terry (Teamrude) has four hybrid cams that are available to better match your particular riding needs.

  • Like 1

Share this post


Link to post
Share on other sites

On the Wiesco website they now show piston kits all the way up to 67.5 11-1 compression in the online catalog for the 230f,

but you need one of Terry Millers .010 head gaskets to get close to the Wiesco advertised compression. (Recommended)

ImageUploadedByThumper Talk1461431769.940899.jpg

Edited by adnohguy

Share this post


Link to post
Share on other sites

ImageUploadedByThumper Talk1461810394.753790.jpg

69mm, 13-1 compression and +.005 above the deck =.039 squish clearance.

Then add either a 4mm or 6mm stroker crank on top of that.

This piston with rings, pin and clips weighs less than a stock piston with rings, pin and clips.

Instant gratification.

Edited by adnohguy

Share this post


Link to post
Share on other sites

Nothing wrong with a 0.039 squish clearance.

 

And CR is the secret to bottom end, if you can avoid detonation.  My Powroll 218 is 11:1 with a Torque cam and survives with 1 degree less timing on pump premium (instead of pump regular on 10:1). The 230s have a different advance curve so may not be as sensitive.  Ness le French posted info on his research for a 230 advance curve.  http://www.thumpertalk.com/topic/971921-keihin-fcr-32-mx-on-crf-230-any-experience/

Edited by Chuck.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:


×