Author Topic: Cobra motor disassembly and rebuild (Read 107722 times)

POPS 911 · « **Reply #425 on:** July 03, 2016, 05:00:05 AM »

BILL: Better hope that the late Pace from Ill. put new oil seals in that head and didn't take .060 off the shave job or you be .010 up = BANG you did it again.

Bill/BentON Racing · « **Reply #426 on:** July 03, 2016, 07:13:55 AM »

POP's, I checked clearances, we just fine and then some. Never know, but I think it's ones going to work, we'll see. Of course, all new o rings and seals, OEM or better. Sounds good, I'll know a lot more Friday, Bill

Bill/BentON Racing · « **Reply #427 on:** July 03, 2016, 07:44:31 AM »

POP's, the late BP head....went to Mike Rieck for new guides and seals, also sent new SS valves, we used Kibble white intakes, back cut by Rick Stetson, along with a Rick Stetson, decked head and new Serdi valve job.Also new springs etc. It should be FINE! And yes it's dead level, I checked! Lol, Bill

dragracer · « **Reply #428 on:** July 03, 2016, 11:56:48 AM »

Tune for the heat Bill. Went racing Saturday and couldn't break past 10.60's. Night time runs at Commerce will probably net the best numbers.

By the way, my clutches were seriously going away. But apparently the clutch held up good enough to sheer a few of the sprockets bolts off- I guess the loctite didn't hold. Hmm, or maybe I forgot to put it on. Nevertheless, glad it happened now. Time to pull the wheel to get the holes repaired. Ordering a new set of clutches tonight. Since the bike will be down, I'm planning to pull the valve cover and check things up top. Carbs are coming off too for a cleaning. I need to regain a top 10 position at the next Cup race.

754 · « **Reply #429 on:** July 03, 2016, 01:24:06 PM »

Loctite. Won't prevent shearing, so did they work loose? Solid mount? What wheel?..what size? What bolt pattern?
Time to go to studs, I am thinking.

MRieck · « **Reply #430 on:** July 03, 2016, 04:25:55 PM »

Quote from: Bill/BentON Racing on July 03, 2016, 07:44:31 AM

POP's, the late BP head....went to Mike Rieck for new guides and seals, also sent new SS valves, we used Kibble white intakes, back cut by Rick Stetson, along with a Rick Stetson, decked head and new Serdi valve job.Also new springs etc. It should be FINE! And yes it's dead level, I checked! Lol, Bill

Yes.....it is as good as it can get.

dragracer · « **Reply #431 on:** July 03, 2016, 05:57:33 PM »

Quote from: 754 on July 03, 2016, 01:24:06 PM

Loctite. Won't prevent shearing, so did they work loose? Solid mount? What wheel?..what size? What bolt pattern?
Time to go to studs, I am thinking.

Let me clarify. Its likely the bolts worked loose due to a lack of loctite. Once there was enough threads exposed, as the wheel turned the bolts snagged the swingarm and sheared off. Haven't had a chance to pull the bike out of the trailer yet as the rain came down when I was moving stuff around to get it out. Much needed rain for the garden so I'm not complaining. Hope to have it repaired by the end of the week. Memphis is the following week I think.

754 · « **Reply #432 on:** July 03, 2016, 08:54:36 PM »

Bill have you weighed any of the bikes?

dragracer · « **Reply #433 on:** July 04, 2016, 11:46:23 AM »

I think he said the 1080 motored bike was 395 in Valdosta but I know he reweighed it in Rockingham. Unsure of that number.

Bill/BentON Racing · « **Reply #434 on:** July 04, 2016, 03:46:46 PM »

It weighed 405 in Rockingham with starter motor and pieces. But have a lighter rotor coming, thanks to George Schuld and Mike Rieck. Also removed some things like volt meter, oil temp gauge etc. I want 395-399! Just finished it around 4:20! Finally I think I got one that's ready and right! We'll see Friday night. It's the best so far for me. Thanks, Bill

dragracer · « **Reply #435 on:** July 04, 2016, 06:45:39 PM »

And let the church say: Amen!!

MCRider · « **Reply #436 on:** July 05, 2016, 06:22:43 AM »

Quote from: dragracer on July 04, 2016, 06:45:39 PM

And let the church say: Amen!!

What I say!

kmb69 · « **Reply #437 on:** July 05, 2016, 07:29:16 AM »

Glad to see shocks on the rear!

Bill/BentON Racing · « **Reply #438 on:** July 05, 2016, 09:43:08 AM »

Thanks, it might be next Friday for Test n Tune. Next Wednesday or Thursday supposed to be dyno. Woke up to no A/C, so it takes precedent over most all else! Lol, Bill

dragracer · « **Reply #439 on:** July 05, 2016, 11:34:39 AM »

Quote from: Bill/BentON Racing on July 05, 2016, 09:43:08 AM

Thanks, it might be next Friday for Test n Tune. Next Wednesday or Thursday supposed to be dyno. Woke up to no A/C, so it takes precedent over most all else! Lol, Bill

Not good for the AC to be out in the south while we're going through 100 degree days. Hope all works out. I had to buy two small window units a few years ago to get us by for several days til the repairman could get the job done. Worked out well once unused rooms were isolated. Plus I was able to remove the units and donate them to a local community center that needed them to cool the seniors and children. Took a tax credit for a donation to charity so all worked out well.

POPS 911 · « **Reply #440 on:** July 06, 2016, 04:15:51 AM »

Damm BILL : Congratulation on that 10.30 ET with that COBRA HEAD MOTOR, I thought you said you were going with a BUTCH PACE head

?? That will be a new record for SEL at MAN CUP for a SOHC 750 HONDA. With the DA at Memphis being 250-400 and the tail wind that track is famous for then that bike will be 10. flat on the cool night passes.

dragracer · « **Reply #441 on:** July 06, 2016, 05:34:14 AM »

Quote from: POPS 911 on July 06, 2016, 04:15:51 AM

Damm BILL : Congratulation on that 10.30 ET with that COBRA HEAD MOTOR, I thought you said you were going with a BUTCH PACE head ?? That will be a new record for SEL at MAN CUP for a SOHC 750 HONDA. With the DA at Memphis being 250-400 and the tail wind that track is famous for then that bike will be 10. flat on the cool night passes.

I guess Pops and I may be the only two people on this forum that have no clue as to who BuTch Pace was, or is. Can someone give us a run down please?? I never professed to be a SOHC guru so I'm totally lost on this famous persons identity.

Bill/BentON Racing · « **Reply #442 on:** July 06, 2016, 06:17:49 AM »

First, POP'S, that's my first goal! I think it can run that though and better. Butch Pace I first met in 1977 at the first IDBA meet, same with Terry and Byron, we just talked in the staging lanes. Russ didn't come. But Butch Pace did. He cleaned up. He was RC's Midwest distributor! Privy to porting, boring, pretty much most everything. So a Butch Pace head was a whole lot like a RC one. He was a performance enthusiast until he passed, Bill
Oh its not coincidence that that would be a new record if I can run it! Lol.

gschuld · « **Reply #443 on:** July 06, 2016, 07:23:28 AM »

Butch Pace owned Pace Kawasaki.

He was from Edwardsville, Illinois. He held the Competition Elimination record in 1975 for A/A.

Set 11/1974, 10.19 sec 135.98mph with an 1162 cb750.

Like Billy said, Russ Sr. chose him to be the Midwest distributor for RC. I have a good example of both a Butch Pace ported head and an RC ported head. Mike Rieck extensively rebuilt both for me and would be the best judge for comparing the porting, but from my untrained eye, they sure look similiar

George

gschuld · « **Reply #444 on:** July 06, 2016, 08:47:26 AM »

This, for example is my Butch Pace ported head. It was originally ported to match an 836 (it was custom stamped "Butch Pace 836")

This head got an upgrade to the 33.5 intakes and the chambers opened up to match a big bore piston/cylinder set.

Naturally, Mike worked his magic on this head and it got new guides, valves, springs, ti retainers, etc.

And, BTW, Jim French worked his magic on chamber #4. This head suffered an apparent broken rod in anger, which left a perfectly circular piston shaped indent into the #4 chamber. Jim fixed her up and sent it to Mike for the rest.

Thanks guys.....

George

gschuld · « **Reply #445 on:** July 06, 2016, 08:49:07 AM »

George

dragracer · « **Reply #446 on:** July 06, 2016, 11:14:46 AM »

Quote from: gschuld on July 06, 2016, 08:49:07 AM

George

Mike and Rick did a jam up job on that head. Its too darn pretty to go on an engine. I'd just build a glass case and put it on a shelf for display. Yeah, I know, I lied. Straight on the biggest engine I could build it would go!!!

gschuld · « **Reply #447 on:** July 06, 2016, 11:38:22 AM »

Quote from: dragracer on July 06, 2016, 11:14:46 AM

Quote from: gschuld on July 06, 2016, 08:49:07 AM
George

Mike and Rick did a jam up job on that head.

Straight on the biggest engine I could build it would go!!!

Fully agree on both comments

George

Ericcb750 · « **Reply #448 on:** July 06, 2016, 02:02:57 PM »

That head is beautiful. I am a rookie when it comes to the hot rod Honda thing but I got my parts (head, cylinders, crank, rods, etc) from Mike a little while back...It truly is freaking amazing, It is super cool to see it next to a stock head. I only have a Stage 2+ but man, that thing is flawless. I cannot wait to run it and compare the ported 836 wiseco with Webcam 63A to my stock 736. This Cobra motor looks like an absolute beast.

Just want to thank everyone here for teaching me so much about these engines and bikes and give a shout out to Mr. Rieck...he's the man, Wicked cool guy and treated my stuff like it was going in his personal bike...Took the time to explain everything to me .... I know my face is going to hurt after breaking that motor in from the #$%* eating grin I'll have on...

Bill/BentON Racing · « **Reply #449 on:** July 06, 2016, 05:26:43 PM »

+1 , what you said! We hope it's a beast! Dyno next week, keep us posted on your build and g'luck, Bill

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Author Topic: Cobra motor disassembly and rebuild (Read 107722 times)