Author Topic: CB750 Wet Sump Conversion - Sumpthing  (Read 73498 times)

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Offline voxonda

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #200 on: March 14, 2018, 02:26:41 AM »
thats not a great pipe , for max power you need to find a way to pair the pipes together 1 and 4 , 2 and three the lengths of the headers is also crucial .
looking at your first design you are not only going to loose power you also have reduced ground clearance considerably .
i think the only way to make it work is to go under the sump some how

That "loosing" power is something we will see at the Dyno. In my experience it is fractional but the reduced ground clearance is my main concern too. Agree that coupling 1&4, 2&3 is favorit but in this stage need to come up with a usable system to test the wet sump. Now looking into having the both collector side by side under the oilpan. Looks promising.
Better sorry for failing then for the lack of trying.

Offline gschuld

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #201 on: March 14, 2018, 06:00:45 AM »
thats not a great pipe , for max power you need to find a way to pair the pipes together 1 and 4 , 2 and three the lengths of the headers is also crucial .
looking at your first design you are not only going to loose power you also have reduced ground clearance considerably .
i think the only way to make it work is to go under the sump some how

That "loosing" power is something we will see at the Dyno. In my experience it is fractional but the reduced ground clearance is my main concern too. Agree that coupling 1&4, 2&3 is favorit but in this stage need to come up with a usable system to test the wet sump. Now looking into having the both collector side by side under the oilpan. Looks promising.

Rob, perhaps something like this would be ideal.  1/4 and 2/3 pipes together, and coming together tight side by side under the pan, then merge to 1 and out.  It’s a more difficult fabrication challenge getting those primaries shaped like that though😒

George

Offline voxonda

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #202 on: March 14, 2018, 07:43:37 AM »
Hi George,

Thanks for sharing your thoughts! Yes this is also a possibility, but since the main goal is to be able to test the wet sump and not trying to find the perfect exhaust (yet), I decided to go my first route, but by replacing the collectors side by side under the pan to still have decent lean angle. Advantage is that the oil plug is free. So now I have to do some welding and painting the primaries. Now have to place the silencer and secubdary collector and then create the connection pipes. But I am getting there......

Rob
« Last Edit: March 14, 2018, 07:45:21 AM by voxonda »
Better sorry for failing then for the lack of trying.

Offline gschuld

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #203 on: March 14, 2018, 08:35:02 AM »
Looks great Rob.  It’s easy for me to suggest difficult to create design ideas when I’m not the one who needs to actually create them😏 🙄

George

Offline dragracer

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #204 on: March 14, 2018, 12:29:23 PM »
I had an 1-5/8" sidewinder on my kz dragbike for years. I scrapped the pipe on the return road at some point and put a small hole in the collector where all the tubes joined. Screwy spot to reweld so I went out and bought myself a brand new, big tube V&H prostock replica pipe. I put the pipe on the bike thinking it would help since I had a 1425cc engine. Well, much to my surprise and total disappointment, the bike lost numbers from one end of the track to the other. The 70' time went up, the ET went up and I lost mph. Needless to say, I found a competent welder to repair my smaller diameter pipe and the bike picked up performance again. Moral of the story; bigger is not always better.

Offline dragracer

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #205 on: March 14, 2018, 01:36:35 PM »
I had an 1-5/8" sidewinder on my kz dragbike for years. I scrapped the pipe on the return road at some point and put a small hole in the collector where all the tubes joined. Screwy spot to reweld so I went out and bought myself a brand new, big tube V&H prostock replica pipe. I put the pipe on the bike thinking it would help since I had a 1425cc engine. Well, much to my surprise and total disappointment, the bike lost numbers from one end of the track to the other. The 60' time went up, the ET went up and I lost mph. Needless to say, I found a competent welder to repair my smaller diameter pipe and the bike picked up performance again. Moral of the story; bigger is not always better.

Offline voxonda

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #206 on: March 15, 2018, 01:03:19 AM »
Wether a pipe works, or not, depends on so many factors. You are right, bigger is surely not always better.
« Last Edit: March 15, 2018, 01:24:39 AM by voxonda »
Better sorry for failing then for the lack of trying.

Offline voxonda

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #207 on: March 16, 2018, 08:04:10 AM »
Little by little the exhaust is getting its (rough) shape.

Better sorry for failing then for the lack of trying.

Offline gschuld

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #208 on: March 16, 2018, 08:18:27 AM »
Looking good.  Forging right ahead I see...👍

George

Offline voxonda

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #209 on: March 16, 2018, 08:31:00 AM »
George,

Try to keep in flow, time is ticking for the new season.

Here a pic of the oil spraying jet in my DOHC camcover.

Better sorry for failing then for the lack of trying.

Offline gschuld

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #210 on: March 16, 2018, 08:49:37 AM »
Gotcha, makes perfect sense👍 Thanks for sharing.

George

Offline bwaller

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #211 on: March 16, 2018, 09:07:56 AM »
Lot's going on there Rob. Just use a thumb brake for the rear!

Offline voxonda

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #212 on: March 16, 2018, 09:12:48 AM »
Haha, not allowed Brent.
Better sorry for failing then for the lack of trying.

Offline NickO

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #213 on: March 16, 2018, 10:57:59 AM »
Lot's going on there Rob. Just use a thumb brake for the rear!

You mean the guy who rides this beast can "back it in", (or does he need it for wheelie control Rob)? ;)

Offline voxonda

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #214 on: March 16, 2018, 11:06:28 AM »
Wheelie control.........hahaha.
Better sorry for failing then for the lack of trying.

Offline BPellerine

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #215 on: March 16, 2018, 06:01:52 PM »
George,

Try to keep in flow, time is ticking for the new season.

Here a pic of the oil spraying jet in my DOHC camcover.
I have often thought honda went through alot of trouble to hide a few oil lines,I never even had to think about cam,rocker wear in bikes that had external feed to the top end.bill
1978 CB 750K ard and webers
another anfob

Offline Bert Jan

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #216 on: March 17, 2018, 02:47:09 AM »
Little by little the exhaust is getting its (rough) shape.

Looks awesome Rob!

Offline voxonda

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #217 on: March 19, 2018, 07:18:30 AM »
Despite the low temps wanted to go ahead with the exhaust to see if I could make it complete today.
Next step is to weld the seams shut and give it a heat resistant spray.
Happy with the outcome, easy acces to oil drainbolt and filter.
Even the ground clearance seems ok, although one can never have enough of that.....


« Last Edit: March 19, 2018, 07:21:19 AM by voxonda »
Better sorry for failing then for the lack of trying.

Offline dragracer

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #218 on: March 19, 2018, 04:36:27 PM »
Looks good. Its coming together.

Offline Bert Jan

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #219 on: March 20, 2018, 01:02:09 AM »
Despite the low temps wanted to go ahead with the exhaust to see if I could make it complete today.
Next step is to weld the seams shut and give it a heat resistant spray.
Happy with the outcome, easy acces to oil drainbolt and filter.
Even the ground clearance seems ok, although one can never have enough of that.....

Sweeeeet! If that exhaust works good we could try to make it profitable to do a production run..

Offline Bill/BentON Racing

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #220 on: March 20, 2018, 04:50:32 AM »
Welcome,  a kinda rocky start,  but that's ok. Appreciate what you are doing. It will be good to see someone try it. One man band, well a lot of us can appreciate that. Hell,  my second language is smashmouth southern.  And some English. So keep us posted and don't get discouraged,  we just a real hard sell sometimes......Bill
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Over 35 years of experience working on vintage motorcycles, with a speciality in Honda SOHC/4 with a focus on the CB750 and other models as well from 1966 - 1985.
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Offline Bert Jan

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #221 on: March 20, 2018, 11:36:53 AM »
Welcome,  a kinda rocky start,  but that's ok. Appreciate what you are doing. It will be good to see someone try it. One man band, well a lot of us can appreciate that. Hell,  my second language is smashmouth southern.  And some English. So keep us posted and don't get discouraged,  we just a real hard sell sometimes......Bill

Thanks dude, appreciate it!

Offline NickO

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #222 on: March 20, 2018, 12:05:24 PM »
Hey Rob, your CB750 looks great, proper race bike, keep up the good work.  8)

Offline voxonda

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #223 on: March 20, 2018, 12:49:19 PM »
Hey Rob, your CB750 looks great, proper race bike, keep up the good work.  8)

Hey Nick, thanks bud! How's the family?

Cheers Rob
Better sorry for failing then for the lack of trying.

Offline NickO

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #224 on: March 21, 2018, 04:03:07 AM »
Hey Rob, your CB750 looks great, proper race bike, keep up the good work.  8)

Hey Nick, thanks bud! How's the family?

Cheers Rob

Great thanks Rob. My daughter is 17 this weekend and my boy is almost 20 and studying engineering at Cambridge University.

I've not had much time to ride any bikes recently though!