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Author Topic: CB750 Wet Sump Conversion - Sumpthing  (Read 6666 times)

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Offline voxonda

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #175 on: March 10, 2018, 10:29:44 am »
Oh that’s interesting.  I had originally assumed the factory oil tank line ports needed to be shut off leaving oil cooler plumbing options at the oil filter only.  Great. ;)

George

The initial setup has the ports closed.  So leaving cooler plumbing to adaptor behind filter. But I prefer the cooler in the return line and not in the (higher) pressure side. So I suggested this to BJ. But we will start testing without a cooler and go from there.
Better sorry for failing then for the lack of trying.

Offline Tintop

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #176 on: March 10, 2018, 12:23:04 pm »
Oh that’s interesting.  I had originally assumed the factory oil tank line ports needed to be shut off leaving oil cooler plumbing options at the oil filter only.  Great. ;)

George

The initial setup has the ports closed.  So leaving cooler plumbing to adaptor behind filter. But I prefer the cooler in the return line and not in the (higher) pressure side. So I suggested this to BJ. But we will start testing without a cooler and go from there.

Would also be interesting to know if there is any oil pressure drop depending on which ports (front/side) & pressure (high/low side).
1977 CB550/4 Cafe - Speed Warrior / BOTM 03/11
1980 CB750F (project)
Whittaker GBF Vintage Racing Sidecar (XS750 power) - ITG / 151's / CMR Racing Products (SOLD)
1976 CB400 SS - stock / BOTM 04/11 (SOLD)
1973 CB750 K - basket case (SOLD)
77 CB550 Cafe build
550/750 Filter Thread
Sidecar Rebuild Thread

Offline voxonda

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #177 on: March 10, 2018, 01:08:58 pm »
Will record all my findings, Brian. And post them here. First have to open up the engine for an overhaul.
Better sorry for failing then for the lack of trying.

Offline Tintop

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #178 on: March 11, 2018, 11:51:29 am »
Will record all my findings, Brian. And post them here. First have to open up the engine for an overhaul.

Yes, sorry to hear about that little set-back Rob.
1977 CB550/4 Cafe - Speed Warrior / BOTM 03/11
1980 CB750F (project)
Whittaker GBF Vintage Racing Sidecar (XS750 power) - ITG / 151's / CMR Racing Products (SOLD)
1976 CB400 SS - stock / BOTM 04/11 (SOLD)
1973 CB750 K - basket case (SOLD)
77 CB550 Cafe build
550/750 Filter Thread
Sidecar Rebuild Thread

Offline voxonda

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #179 on: March 13, 2018, 02:50:41 am »
In the meantime, while waiting for parts, started with constructing a suitable exhaust system. To make life somewhat easier cut up an old four into one which I made years ago using the oem primaries. It is not exactly what I wanted but it will do.
Need to do a little cutting and welding but this it a first step.
 
Better sorry for failing then for the lack of trying.

Offline gschuld

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #180 on: March 13, 2018, 06:31:20 am »
Rob,

Besides the extra weight of the thicker gauge tubing used in the factory head pipes, it’s hard to argue about the carefully design gentle curvaturecof the shape.  Funny how similar they are in profile to the hand bent 1st generation race pipes.

I’m guessing that you are creating a 4 into 2 into 1 style pipe along the lower right side?  It’s going to be a tight fit while keeping clear of the Sumpthing and keeping it tight enough to avoid the full lean angle grounding concerns.  The only other option it seems is to have the 2 into 1 individually on each side and join together behind the Sumpthing.  I’m guessing that would be too convoluted.  4 individual pipes CR style is the other obvious path. 

If anyone can modify factory header pipes to work, you have my vote.

Watching with interest🧐

George
« Last Edit: March 13, 2018, 06:34:49 am by gschuld »

Offline voxonda

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #181 on: March 13, 2018, 07:59:17 am »
Only downside of the oem tubing is the rather small diameter of 35mm. But I do love the curve of them.
A preferred 4-2-1 on one side of sump would kill ground clearance so had to opt for two individual 2 into 1 and join behind sump. Rather have the #1 and #4 coupled and #2 and #3 due to firing order  but cant have them all. Maybe in a later stage.
« Last Edit: March 13, 2018, 09:03:38 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 #182 on: March 13, 2018, 08:14:55 am »
Gotcha.  I was wondering how you were going to fit it all on the right side.  It’s going to be an interesting transition with 2 singles coming back together, joining together with a Y and out one side well clear of both the rear of the Sumpthing and the rear tire without having a small radius turn on one of the pipes.  I’m digging your creativity regardless.

George

Offline simon#42

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #183 on: March 13, 2018, 08:15:24 am »
Yes one and four , two and three will give the best power .

Offline voxonda

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #184 on: March 13, 2018, 09:07:24 am »
Gotcha.  I was wondering how you were going to fit it all on the right side.  It’s going to be an interesting transition with 2 singles coming back together, joining together with a Y and out one side well clear of both the rear of the Sumpthing and the rear tire without having a small radius turn on one of the pipes.  I’m digging your creativity regardless.

George

There is enough room behind the sump to join without too small radius tunes. Buit still working on some idea's. We will see.
Better sorry for failing then for the lack of trying.

Offline scottly

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #185 on: March 13, 2018, 09:07:44 am »
Rob, you may want to consider merging the head-pipes together in front of the sump, so there is only a single pipe on each side running past the sump? As far as effect on performance with shorter primaries, only the dyno will tell. ;)
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Offline voxonda

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #186 on: March 13, 2018, 09:34:40 am »
Scott, it is something I also consider. But it does effect the power output. It would make the routing of a single pipe next to the sump easier.
Better sorry for failing then for the lack of trying.

Offline gschuld

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #187 on: March 13, 2018, 09:34:56 am »
FWIW, Carpy’s Yoshimura copy pipes have gone through several suppliers and versions.  Some hang quite low under the engine.  In fact, for a visual example, the one pictured below looks to clear an oil pan lowered 2”

Might it be worth considering for a road racer simply going under the Sumpthing along the centerline assuming the ground clearance isn’t an issue.🧐

George

Offline bwaller

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #188 on: March 13, 2018, 09:42:36 am »
What about a flat (4 in a row) collector directly under the pan? I don't know the results in such a case, but have seen them before. It would take your special touch to fab a cool piece.

Offline gschuld

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #189 on: March 13, 2018, 09:50:28 am »
What about a flat (4 in a row) collector directly under the pan? I don't know the results in such a case, but have seen them before. It would take your special touch to fab a cool piece.

Right, like the early Murray pipe, similar to the later Monty Campbell X-pipe

George

Offline simon#42

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #190 on: March 13, 2018, 11:03:13 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

Offline 754

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #191 on: March 13, 2018, 11:58:33 am »
I am betting smaller primary   make more torque..
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Offline calj737

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #192 on: March 13, 2018, 12:27:10 pm »
I am betting smaller primary   make more torque..
I went to the same school, Frank.
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Offline simon#42

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #193 on: March 13, 2018, 12:45:16 pm »
you went to school cal ?

Offline voxonda

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #194 on: March 13, 2018, 12:59:38 pm »
I am betting smaller primary   make more torque..

Diameter, length of primaries make torgue up or down scale. Form and length of the collectors too.
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Offline calj737

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #195 on: March 13, 2018, 01:34:19 pm »
you went to school cal ?
Long enough to school you, Simple.
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Offline Tintop

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #196 on: March 13, 2018, 04:27:54 pm »
Rob given this going to be a chop and fit exhaust, why not try and incorporate Captain's (Brent H) 360 degree design.  The NASCAR boys use very flat collectors for ground clearance, maybe some packaging ideas there?
1977 CB550/4 Cafe - Speed Warrior / BOTM 03/11
1980 CB750F (project)
Whittaker GBF Vintage Racing Sidecar (XS750 power) - ITG / 151's / CMR Racing Products (SOLD)
1976 CB400 SS - stock / BOTM 04/11 (SOLD)
1973 CB750 K - basket case (SOLD)
77 CB550 Cafe build
550/750 Filter Thread
Sidecar Rebuild Thread

Offline gschuld

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #197 on: March 13, 2018, 06:34:21 pm »
Rob,

You are going for something like this right, squeezing around the sump?

George

Offline scottly

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #198 on: March 13, 2018, 08:01:33 pm »
I am betting smaller primary   make more torque..
Smaller primary diameter made less torque on the FT 500, AKA Ditch Pump. ;)
Don't fix it if it ain't broke!
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Offline voxonda

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Re: CB750 Wet Sump Conversion - Sumpthing
« Reply #199 on: March 14, 2018, 01:16:06 am »
Rob,

You are going for something like this right, squeezing around the sump?

George
 

Thuis could be, but still thinking of other options too.
Better sorry for failing then for the lack of trying.

 

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