I opened it up where the pipe connects to the head(there was a monster weld cutting airflow). There was also a 1.5 inch section that narrowed the diameter of the pipe about 3/8". It was about one inch from where the pipe connects to the head again that I removed and replaced it with a larger section so that there would be no restriction. And I had to cut and bend it in a few areas so that it could clear the FCR's. Nothing drastic though, as far as bends are concerned(doesn't seem to be any blocking of airflow or restriction of any kind). I took the disks out and placed a free flowing end cap. I figured the less restriction the more top end I would recieve. I think they put that narrow part in so it would have some torqe. My Raptor has a ton of torque right now, but rather have more top end.

You would love to see the cinders it makes the dunes look like burms and whoops. Take a look at PredFan's fics on his page. shows some hills from far off.

 

A good friend of mine has got a 727 done by Curtis and it has the high rev cam, FCR's with stock valves and its a runner. I know Craycraft puts out some fast bikes also and it would be interesting to see some Craycraft and Sparks bikes hook it up and see what happens. I got a good look at the head Curtis had done for it and it was a little different from other port jobs I had seen. Slim

 

I didn't know Sparks had build a 727 yet. They told us that they wouldn't be building one, but it's great to see that he is working on different setups. I checked out our sparks' heads and they did look different than the craycraft head. I wish I could have had them side by side though.

 

The 727 was done for him I guess you could say specially for him. The guy i'm talking to is in pretty good with Curtis personally and has done a lot of buisness with him; he owns an ATV shop(SANFORDS ATV AND REPAIR-OWNER FREDDY SANFORD). I would imagine he would do one for someone else who wants one though? Slim

 

SLIM660 - Have you raced him yet? I see that you have the 685 web cam. Did you ever try the stage two hotcam. What is the difference in the two cams, duration & lift? What type of fuel mixture are you running(or is that a secret)?[img]i/expressions/face-icon-small-wink.gif[/img]

 

Raptor660fam I'd try your dads Sparks X-6 if he will let you I had better luck with that pipe system then the Graydon/CT! Its a free mod if he lets you and it might up your performance.





Pat

 

PatsRaptor - Thats a very good Idea. When I first built my engine and broke it in I used the x-6 pipe because I was still working on my CT pipe. I don't really remember the difference because it was only a break in. I think I will try that though. Thanks.

 

Raptor660Fam;

I am running stock (modified) Carbs with a dual feed system. Ferrea Stainless Steel valves.

My next item to try is FCR Carbs soon.

 

sparks pipe on a craycraft?? That will start a family fued[img]i/expressions/face-icon-small-wink.gif[/img] Maybe a mbrp full bore headpipe with the ct slip-on might be the ticket. A larger headpipe for less torque and more top end?

I used to believe that all the pipes were close to one another, but now that guys have modded hard there are lots of differences.

Still looks to me that you need to gear them closer and run them again. I am sure some math guru on here can figure out the gearing difference in 3rd to even the 01's to the 03's ratios.

You got hte FCR's dialed perfect? I have seen a lot that seem to be a little less than perfect. Why did you toss the stock carbs? I think ubetrun said the stock carbs gave him more top end than the fcr's. ( i think i read that somewhere) A egt guage will verify in a hurry.

How did the sparks motors mount there FCR's??


Did you guys run any flat drags? You said you had them out of the hole for how long? Everyone started in the same gear?

 

With Raptor660fam's and families setups.....the 03 Raptor's are geared 2% lower. If he switches too a 45 tooth rear he will have 1% lower gearing than his buddies. For comparism purposes between percentages if Raptor660ram leaves his setup as is and changes too a 13 tooth front sprocket his gearing will be 8% higher than now.