"La Pastinaca" CB450 498cc Big Bore Engine Built By DWMS Racing!

joeyputt

The green flag sets me free
I have been provided the great honor and priviledge of working with Brother Habanero52 to build the engine for his CB450 "La Pastinaca"!

We will be completely disassembling this engine and building it from the bare cases with a lot of photos so for all of you who share the love affair with the CB450, or high performance engines in general, you will not want to miss this thread!

Here are a couple photos of the engine as I received it from Brother Habanero52.

000_0001.jpg


000_0002.jpg
 
Re: "La Pastinaca" CB450

I'm working on one myself, will be interesting to compare the two!
Can't wait to see what madness you come up with Joey!
 
Re: "La Pastinaca" CB450

Brother Swagger I can not wait to see yours! This is the kind of build that I always look forward to doing as Brother Habanero52 is really great to work with and is providing a wonderful list of parts!

I started disassembling the engine for cleaning and inspection while some of the parts were on the way.

I removed the cylinder head, cylinders, side covers, etc.
000_0010.jpg


I disassembled the cylinder head and started cleaning it in preparation for all of the machine work. Notice the CB450 has an aluminum head with steel semi hemispherical combustion chambers.
000_0002_00.jpg


000_0016.jpg
 
Re: "La Pastinaca" CB450

If it looks like any of your others it'll be stunning!
 
Re: "La Pastinaca" CB450

Thank you for the compliment Brother Swagger it means more to me than you realize, your work is very nice as well!

I split the cases yesterday.
000_0003.jpg


Today some of the parts came in including a close ratio 5th gear!
000_0009.jpg


Before I fully disassembled the bottom end I wanted to test fit the close ratio fifth gear so I removed the main and counter transmission shafts and gears.
000_0003_00.jpg


This photo shows the mainshaft with the stock 5th gear.
000_0005_01.jpg


The mainshaft with the stock 32 tooth 5th gear removed.
000_0007_01.jpg


Here is the mainshaft with the 31 tooth close ratio 5th gear installed, and the stock gear in the bottom of the photo.
000_0011_00.jpg


I installed the mainshaft, countershaft, and gears back into the case to check the fitment of the close ratio 5th gear, it went togethor beautifully so now I can completely disassemble the cases for cleaning.
000_0012.jpg
 
Re: "La Pastinaca" CB450

Joey,

Is that a new 31T and does it come with a matching gear for the other shaft or does it just have more backlash? That gear looks brand new - is it?

NOVA in the UK list top gear as 25-23 and first as 16-30 so something must have changed over the years.
 
Re: "La Pastinaca" CB450

The honor is all mine! I am delighted with the way you are handling the project and the communication between us.
I know that this will be an enviable engine once you have completed it.
Thank you for everything.
:D ;D
 
Re: "La Pastinaca" CB450

Teazer, that is a spanking brand new gear! It did not come with a matching gear, for it is not available any more.
 
Re: "La Pastinaca" CB450

Brother Teazer as Brother Habanero52 already mentioned it is a new gear, the stock gear in this engine was a 32 tooth and the new gear is a 31 tooth. Both gears can be seen from the side in the photos above as well for a tooth count.

The backlash specs that I have for the CB450 show the servicable limits as 0.0037-0.0074 in. or 0.094-0.188mm for 3rd, 4th, and 5th gears. The new gear falls within this range, I will put gauges on it and get the exact number if you are interested.

The gear appears to have been designed and cut with the correct amount of backlash to be run as a drop in replacement for use with the stock countershaft gear, it definately has a very nice fit!
 
Re: "La Pastinaca" CB450

VonYinzer said:
Right on Joe! This will be a jewel for sure.

Brother it is definately going to be pretty but a lot of the jewels will be on the inside! Yesterday I received two big boxes of parts that Brother Habanero52 sent and was like a child at christmas going through them all! Hahahaha! You would think after all of these years I would be tired of looking at shiny new parts but for me it never gets old!
 
Re: "La Pastinaca" CB450

New gears are always a nice thing and if the lash is in spec and tooth engagement is deep enough you should be good to go. We do something similar on GT570 using GS gears and it's an old trick on Honda 305s to use a Dream top gear with one less tooth.

Is that a closer top gear or higher first gear? According to NOVA it's bottom gear that uses 30T ( different again).

Do you have all the tooth pairs and I can compare them to what NOVA has. It is possible that different years used different gear ratios or maybe General Export Vs UK or something.
 
Re: "La Pastinaca" CB450

Brother it is a K5 engine and 5th gear on the main shaft. I am removing the crankshaft and transmission now, I have a computer next to my work table, for final inspection and cleaning and can post all of the gear counts for you.
 
Re: "La Pastinaca" CB450

Joe,
That's really interesting. I went on line and trolled through parts list and found most of the gears and 32T is listed as top gear mainshaft as you said. All the gear pairs I could match were around 58/59 teeth but NOVA lists them as 45/46/48 which is very different. CB350 and 360 and race kit trans are in the 55-58 tooth range. I wonder what NOVA used as their starting point? In fact the gears that NOVA list re very close ratio. I wonder if that was a race kit trans they were measuring. I have no data on those.

If you get a chance to count teeth sometime, I'd appreciate it. From the parts list it looks like 41- (18), 22-(37), 26-33, 29-29,32-27. The numbers in brackets were guesses based on tooth counts in the other pairs. They are probably fixed.
 
Re: "La Pastinaca" CB450

Sure that is no problem at all Brother, I just got the crankshaft and transmission out and am working on cleaning the cases and I am going to record the transmission numbers for Brother Habanero52's build sheet so I can post them here for you as well this afternoon.
 
Re: "La Pastinaca" CB450

Here is a photo of the top case half after I removed the crankshaft, main shaft, countershaft, gears, etc. and started cleaning it.

000_0020.jpg


Here are the transmission numbers -
17-41, 22-36, 26-33, 29-29, 32-27 (31-27 for this engine with the close ratio gear)

So the ratios would be -
1st - 2.41:1
2nd - 1.64:1
3rd - 1.27:1
4th - 1.00:1
5th - 0.844:1
(5th in this engine with the close ratio gear will be 0.871:1)

Brother Teazer I have found the same information with the NOVA standard values being 16-30, 19-27, 21-24, 23-23, 25-23 which as you said run anywhere from 45-48 paired compared to the stock gearing of 58-59 paired. I also wonder if NOVA's standard value measurements are from their old race kit trans which I also do not have the specs for, I know that they are no longer offering the five speed but do have a six speed available. The last time I looked Team Hansen had the last available NOVA 5 speeds but they do not list the ratios for it.
 
Re: "La Pastinaca" CB450 Parts List And Photos Added!

I know a lot of you are interested to know what all is going into Brother Habanero52's engine so here is the parts list and a few photos! I will show each part in more detailed photos as I install them but this will give you all a better idea of what we will be doing.

Parts list -
Complete Athena gasket set
Solid copper head gasket
Mikuni VM32 carburetors
Kibblewhite black diamond intake valves
Kibblewhite black diamond exhaust valves
Kibblewhite bronze intake guides
Kibblewhite bronze exhaust guides
Kibblewhite H.T. steel lash caps
Kibblewhite racing valve spring conversion kit with titanium retainers
The camshafts and rockers have been shipped to Megacycle for regrinding
Tsubaki cam chain
THR 74mm racing pistons
Barnett clutch friction plates and new springs
Electronic ignition
Close ratio 5th gear
New starter chain
Rebuilt starter
Rebuilt stator
Stainless steel engine bolt set
Chrome valve cover bolt set
16 tooth front sprocket
New left cylinder head cover/cam bearing
New right cylinder head cover/cam bearing
New base point cover/cam bearing
New tach gear cover/cam bearing
New rear cam chain guide
New roller cam chain guide
New front roller cam chain guide
New cam chain tensioner
Jet kit

For the cosmetic finish Brother Habanero has decided on a satin black for the engine cases, cylinders, cylinder head, and stator nose cover with polished aluminum clutch, stator, sprocket, oil filter, and all of the cam covers. We will also be polishing the cylinder heads fin edges and the Honda lettering on the stator nose cover as well!

Here is a photo of the new Mikuni VM32 carburetors and K&N air filters!
000_0010_00-1.jpg


This photo shows the beautiful THR 74mm racing pistons!
000_0006.jpg


There are still a few parts on the way but here is a photo of what has arrived already!
000_0023.jpg
 
Re: "La Pastinaca" CB450 Parts List And Photos Added!

That's a giant pile of the good stuff....
 
Back
Top Bottom