Author Topic: CB400F - 466cc big bore kit on eBay (Read 18332 times)

OLDN64 · « **on:** July 12, 2012, 04:43:24 AM »

G'day guys,

Just wondering if anyone has used one of these ?

http://www.ebay.com.au/itm/HONDA-CB400F-466cc-BIG-BORE-PISTON-KIT-NOS-NEW-CB-400-RINGS-GASKET-CB400-4-FOUR-/271012265330?pt=Motorcycles_Parts_Accessories&hash=item3f1996fd72#ht_1377wt_1398

I'm not too sure about the massive increase in bore/cylinder size on the little 400.

Does anyone know if there is much else involved ? I'm imagining that this would require at least a re-jet on the carbs, but can anyone think of anything else I should consider if they're worth the money ?

neevo · « **Reply #1 on:** July 12, 2012, 05:30:02 AM »

I hear they are essentially this kit but for more money:

http://bit.ly/N8IC7w

I will be putting one of these in my 400, it will require reboring the cylinders but I haven't heard much about jetting. My assumptions would be some minor tweaks would be required.

Reports seem good about the quality/performance.

Greggo · « **Reply #2 on:** July 12, 2012, 06:07:51 AM »

Member 'Camelman' is one of the resident experts on big bore CB400's..Maybe send him a message. He's done the 466cc bore kits before I believe.

Kwality · « **Reply #3 on:** July 12, 2012, 07:48:58 AM »

There are a few threads on here about theSe kits. Member Jessezm has one installed. From memory it's the largest bore that you can take out the stock barrels, and you lose the taper at the base of the cylinder, making installation a little trickier.

Search '400f performance modifications' in these forums for a good discussion on not only the big bore kit, but other mods that can be done to give the 400 more bang.

camelman · « **Reply #4 on:** July 12, 2012, 08:01:32 AM »

I seem to have built a reputation. Greggo, when are you going to add a 400 to your stable?

I recommend the kits from cruzin-image. I've bought a number of his kits (non 466 kits too) and have been impressed with the quality and speed of shipping, especially for under $150 shipped!! You might find some casting marks left on the piston crowns, but nothing to be concerned with and the piston dimensions have been correct and consistent for me. You might have trouble finding a shop to bore that small of a cylinder, but they exist and others here can help find a shop if necessary.

Jetting should not change much at all with just the 466 kit. If you keep the stock intake, which I recommend, then leave the stock jets in to see how they work. You might need one step larger or smaller, but you won't require a large jet size change. I recommend carb boring by denoonsp too. That is the icing on the cake and really wakes the engine up. Jetting with bored carbs should only require a single size increase on the mains...depending.

Good luck!
Camelman

Greggo · « **Reply #5 on:** July 12, 2012, 08:12:09 AM »

Camelman, I seem to remember asking if you had one to sell me

HondanutRider · « **Reply #6 on:** July 12, 2012, 09:55:11 AM »

These kits seem to be listed for the CB400F. I wonder if they would also work for the CB350F?

Sparked · « **Reply #7 on:** July 12, 2012, 10:43:47 AM »

Quote from: HondanutRider on July 12, 2012, 09:55:11 AM

These kits seem to be listed for the CB400F. I wonder if they would also work for the CB350F?

Same question I was going to ask. It would make sense that you would need a set of 400f cylinders to bore out.

What other changes would be necessary to optimize the big bike kit?

How much work would be needed for the 350f head to breath properly?

Or would it be smarter to swap a full 400f top end?

What are the differences between the 350f and 400f cams?

camelman · « **Reply #8 on:** July 12, 2012, 12:00:17 PM »

Same cams between 350f and 400f. The 466 kit will not fit in the 350f cylinders, but you could swap out the 400f cylinders, head and studs if you wanted. I don't think it is worth the effort (better to just swap in an entire 400f engine), but that's just my opinion. the 400f head does not line up all that well on the 350f setup and will require some minor modifications.

The 400F stock pistons are a good swap into a 350f cylinder. They take the 350f liners to their very limits just like the 466 kit does to the 400f engine, but they are a huge improvement to the 350f... supposedly.

I've ported out a 350f head and it made a world of difference. I have one coming from Rieck that was ported and rebuilt, which I imagine will provide even greater benefits. The 350F ports weren't great, and should be cleaned up if you radically increase the engine displacement. The next choke point is the carbs, which I'd recommend to bore out (DenoonSp is a good option for that) or replace. Boring out the carbs and increasing the displacement will not overly tax the intake and exhaust systems, and should not require extensive rejetting work.

Camelman

Sniper X · « **Reply #9 on:** July 12, 2012, 02:24:45 PM »

Isn't there only 4bhp difference between the 350F and 400F?

Sparked · « **Reply #10 on:** July 12, 2012, 05:19:17 PM »

Are there any major differences between the 350f and 400f heads? Differences in valve sizes, flow, etc??

Stev-o · « **Reply #11 on:** July 12, 2012, 05:28:40 PM »

Here's the link to the eBay seller cruzin image Camelman mentioned...

http://www.ebay.com/itm/75-77-HONDA-CB400F-466cc-BIGBORE-PISTON-KIT-WITH-GASKET-/160823346573?pt=Motorcycles_Parts_Accessories&hash=item2571d1858d&vxp=mtr

camelman · « **Reply #12 on:** July 12, 2012, 06:06:29 PM »

That 4HP, if that's all it is, really are noticable. There are some big differences between the two heads. The 400 head intake ports are much better designed than the 350 intake ports, and the intake valve is 1mm larger on the 400f I think.

mattcoff1 · « **Reply #13 on:** July 12, 2012, 06:31:23 PM »

Hey
I used the kit from cruzin image
quality was good no problems... got it running
about a month ago

Matt

Sparked · « **Reply #14 on:** July 12, 2012, 06:58:26 PM »

Sounds good Matt. Dis you have to change anything with your carb set up? Do you have a build thread for your bike?

mattcoff1 · « **Reply #15 on:** July 12, 2012, 07:02:41 PM »

No no build thread
Im still getting it dialed/broken in...
Matt

camelman · « **Reply #16 on:** July 12, 2012, 07:39:23 PM »

Matt, I'm interested to know how you dial in that 466 if the rest of the system is stock. Don't be afraid to go down a jet size if necessary. Larger displacement can do that.

mattcoff1 · « **Reply #17 on:** July 12, 2012, 08:01:58 PM »

http://i290.photobucket.com/albums/ll272/mattyc1_photos/400new026.jpg

Its close to stock.new muffler.k&n filters
had 38 slow jets trying 40s now
I think one size up mains
Its only gone 100 miles
I will change oil and re do 3k checks when i get back from vac next week...

Matt

Stev-o · « **Reply #18 on:** July 12, 2012, 08:30:29 PM »

Matt - beautiful bike! BOTM nominated

mattcoff1 · « **Reply #19 on:** July 12, 2012, 08:39:47 PM »

Thanks steve o
Its big fun to ride!!!

Matt

Stev-o · « **Reply #20 on:** July 12, 2012, 08:41:53 PM »

Quote from: mattcoff1 on July 12, 2012, 08:39:47 PM

Thanks steve o
Its big fun to ride!!!

I bet. A 400F is in my future...

crazypj · « **Reply #21 on:** July 12, 2012, 08:44:16 PM »

Haven't used a kit but I built a 490 conversion that didn't have any problems except clutch slip with stock springs

Sparked · « **Reply #22 on:** July 12, 2012, 09:46:03 PM »

Quote from: crazypj on July 12, 2012, 08:44:16 PM

Haven't used a kit but I built a 490 conversion that didn't have any problems except clutch slip with stock springs

Hey PJ, What parts did you use to build up the 490cc engine?

camelman · « **Reply #23 on:** July 13, 2012, 12:12:41 AM »

Try EBC discs with Barnett springs. It'll handle well over 60 hp with a snappy clutch grab.

Matt, that's beautiful!!!

Robbnc · « **Reply #24 on:** July 13, 2012, 08:58:55 AM »

I just got my 466 fired up last week . I started with 40 slow and 90 main jets and it idles and revs up real good. I won't know for sure until I can ride it and
right now I'm waiting on brake parts and I gotta paint the tank.

Sniper X · « **Reply #25 on:** July 13, 2012, 09:36:50 AM »

Will the 400 head bolt up to a 350?

camelman · « **Reply #26 on:** July 13, 2012, 10:59:10 AM »

Sniper,

The oil holes on the left and right sides of the head won't line up without some metal work, and you'll need to swap out some of the engine studs to shorter ones. The cylinder diameters are different too, so the combustion dome will overlap the cylinder walls and you might need a custome cylinder head gasket. Compression ratio will also be slightly decreased. For these reasons, if you are going to swap a 400 head onto a 350 engine, then swap the cylinders too. I think that will require opening up the holes in the upper case on the 350f to accept the larger 400 cylinder liners though... again... a headache. A complete engine swap would be easier.

Try porting out the 350f head instead. It'll provide a lot more power than the stock head and won't create all the fitment issues of force fitting a 400 head and cylinders to your 350 block. The big difference between the two heads is better flow on the 400f and larger intake valves. You can easily fix the airflow issue by porting the 350f head. The displacement of the 350f doesn't really justify the larger intake valves for street use though. You'd need to run higher revs to really benefit from increasing the intake valve size, and you probably don't drive around like that anyway. If you are looking at power, then stick to the porting for a quick power increase in the streetable RPM range.

One of the early posts in this thread referenced another thread where a bunch of us commented on how to make more power out of these engines. We all seemed to be in agreement on how to do it, so you'd do well to read that post.

Camelman

crazypj · « **Reply #27 on:** July 13, 2012, 11:01:25 AM »

Quote from: Sparked on July 12, 2012, 09:46:03 PM

Quote from: crazypj on July 12, 2012, 08:44:16 PM
Haven't used a kit but I built a 490 conversion that didn't have any problems except clutch slip with stock springs

Hey PJ, What parts did you use to build up the 490cc engine?

Fitted 500f liners to block and modified 56mm pistons, don't remember details, it was late 80's

Sniper X · « **Reply #28 on:** July 13, 2012, 11:54:31 AM »

Quote from: camelman on July 13, 2012, 10:59:10 AM

Sniper,

The oil holes on the left and right sides of the head won't line up without some metal work, and you'll need to swap out some of the engine studs to shorter ones. The cylinder diameters are different too, so the combustion dome will overlap the cylinder walls and you might need a custome cylinder head gasket. Compression ratio will also be slightly decreased. For these reasons, if you are going to swap a 400 head onto a 350 engine, then swap the cylinders too. I think that will require opening up the holes in the upper case on the 350f to accept the larger 400 cylinder liners though... again... a headache. A complete engine swap would be easier.

Try porting out the 350f head instead. It'll provide a lot more power than the stock head and won't create all the fitment issues of force fitting a 400 head and cylinders to your 350 block. The big difference between the two heads is better flow on the 400f and larger intake valves. You can easily fix the airflow issue by porting the 350f head. The displacement of the 350f doesn't really justify the larger intake valves for street use though. You'd need to run higher revs to really benefit from increasing the intake valve size, and you probably don't drive around like that anyway. If you are looking at power, then stick to the porting for a quick power increase in the streetable RPM range.

One of the early posts in this thread referenced another thread where a bunch of us commented on how to make more power out of these engines. We all seemed to be in agreement on how to do it, so you'd do well to read that post.

Camelman

Thanks for clearing that up! I wasn't really considering it but wondered if they bolted right up.

camelman · « **Reply #29 on:** July 13, 2012, 12:08:53 PM »

Someone else might be able to chime in on directly dropping a 400 block onto the 350 case without enlarging the cylinder openings. I have one of each engine apart right now, but doubt I'll have time to check fitment for a few weeks.

I'm interested to hear about that 490!!

crazypj · « **Reply #30 on:** July 13, 2012, 03:55:06 PM »

I remember it was the only '400' I've ever ridden that would wheelie in second gear straight off the throttle (I hate abusing clutch)
Take it 6 grand chop and then just give it full throttle (loads front suspension and comes right up when you re-accelerate)

Sparked · « **Reply #31 on:** July 13, 2012, 08:56:39 PM »

Reason I was thinking of using this kit on a 350f engine is I have 1.5 that are in need of a rebuild that are my spares. And it would defiantly wake up the little engine. All I need to find is a 400f top end with a stuck piston cheap.....

classic bike tuner · « **Reply #32 on:** July 14, 2012, 02:38:51 AM »

you can take the liners from a 400 and fit them in a 350 cilinder and then bore these for the 460 pistons
then you keep your 350 looks but its more work

if you need 400 liners i have a lot of them

Sparked · « **Reply #33 on:** July 16, 2012, 07:43:58 AM »

How much would a set of 400f liners cost me? having a stock looking 350f engine that isn't would be a fun build.

Calumjs · « **Reply #34 on:** October 19, 2016, 02:36:43 AM »

Firing up an old thread but I just got my 466 eBay kit ad I'm wondering what size I get my machine shop to bore my cylinders to? I'm guessing 54.5?

-CB-Jamie- · « **Reply #35 on:** October 19, 2016, 05:39:21 AM »

I think the machine shop measured my pistons and bored to suit. 54.5 sounds about right though.
I had to go down from #75 to #70 mains as well.

Calumjs · « **Reply #36 on:** October 19, 2016, 02:14:51 PM »

Thanks for the reply, I was surprised that there was no paperwork with the piston kit with all those details on it. Does the machine shop just need to measure the piston or do I need to install the rings onto the pistons for them to measure too?

Bodi · « **Reply #37 on:** October 19, 2016, 03:42:06 PM »

Just the pistons. You gap the rings in the finished bore.

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Author Topic: CB400F - 466cc big bore kit on eBay (Read 18332 times)