Topic: built motor on ebay

[yoomit]

http://cgi.ebay.com/ebaymotors/HONDA-CB750-ENGINE-COMPLETE-PRO-1-RACING-TEMPE-CYCLE_W0QQcmdZViewItemQQhashZitem1e5a157604QQitemZ130360374788QQptZMotorcyclesQ5fPartsQ5fAccessories

does this seem overpriced?  not very detailed info either.
but curious how good it runs.

[MCRider]

I hate these kinds of ads/auctions. Always so many holes in the descriptions. A WebCam AND RC valve spring kit? Which is it?  Any crank work?

6 weeks to build? If its a part time project. And ... it is an F2.

Probably not too high if that's what you want. But there is no way of knowing what is really inside.

[wannabridin]

it does look pretty tho.  that's a good color scheme for a blacked out motor

[mlinder]

Way too much, in my opinion.

[MCRider]

After re reading it they probably meant a WebCam camshaft and RC Engineering valve springs.

if so the spring kit has to be 20 years old though it may never have been used, its old tech.

Add it up: piston kit and misc $500; head, cam, misc $1,000. Bottom end work assume lighten and balanced crank and misc $1000; misc $500 labor $1,000. Its a retail price, but it adds up.

[yoomit]

the lack of details is what would make it suspicious.
and that price doesn't even come with CR's, which i'd think would be necessary for an 850 bore...that's another $700 or so. ouch.

that said, i'm unfamiliar with the shop that put this together, they may be reputable - anybody know these guys??

[Sam Green Racing]

The said builder.  http://www.pro1racingheads.com/Pro1racing_heads/Home.html

Sam.

[sangyo soichiro]

Judging from the picture of the open case, the crank doesn't look lightened. 

[mlinder]

850 is most likely the cyclex pistons. Great for street use, I'm sure.
But for a track bike?

And who did the porting? What kind of porting?

I didn't see anything about a lightened and balanced crank. If I were selling a 'race engine' I would mention a lightened and balanced crank had been done.

[754]

I only came up with about a 1K in parts so far, he said he did not include porting.

 Borekit, fitted 600ish

 Cam 200-250ish

 Springkit 100-150ish


 plus motor core 200 MAX... leaves a lot on the table for assembly, DiamondCutting, powdercoating...CNC valvejob..

 I think someone should ask for a list of Parts used in build...

[Shenanigans]

Hey they are in Tempe! Maybe I should go stop by and bug them about these motors

[yoomit]

plus, this shop's specialty seems to be in building heads, not necessarily building whole motors.  

[MCRider]

Hey they are in Tempe! Maybe I should go stop by and bug them about these motors

These guys are all over you tube with instructional informative stuff. I like them. I think they are selling a well built motor for retail. Granted I agree with Soichiros observation, not likely a balanced crank. And as they say OEM parts used like a stock cam chain etc. Its not the way I'd go, but another way to skin a cat, could do worse.

http://www.bing.com/videos/watch/video/pro-1-racing-heads-diamond-honing-a-plated-cylinder/FD8079051526A94CA177FD8079051526A94CA177

Depending on what they put in the tranny, and with all the misc stuff it takes to button up an engine, fair retail.

They may not be CB750 specialists, that's my take away.

[Jerry Rxman Griffin aka MuthaF'er]

From 1st hand knowledge, you can easily put $6,000 into one of our engines but you have to go all the way rather than a mild build as they have done.

[MRieck]

From 1st hand knowledge, you can easily put $6,000 into one of our engines but you have to go all the way rather than a mild build as they have done.

You can easily put 2,000.00 in just the 750 head.

[mlinder]

From 1st hand knowledge, you can easily put $6,000 into one of our engines but you have to go all the way rather than a mild build as they have done.

You can easily put 2,000.00 in just the 750 head.

For sure. You can put almost that much in a 350t head

However, It doesn't appear to me they've done anywhere near that, though.

[MRieck]

From 1st hand knowledge, you can easily put $6,000 into one of our engines but you have to go all the way rather than a mild build as they have done.

You can easily put 2,000.00 in just the 750 head.

For sure. You can put almost that much in a 350t head

However, It doesn't appear to me they've done anywhere near that, though.

It would appear so Mark. 

[fastbroshi]

So what's the joke on F2's?  Those were the late 70's models, with the tank color-matching tail right?

[Soos]

Exhaust valves burned frequently, by then the cb750 had a de-tuned cam, the carbs were gas sipper economy models....

Better head design though.
(Correct me , 'cause I probably got 1 or more things wrong )


l8r

[MCRider]

So what's the joke on F2's?  Those were the late 70's models, with the tank color-matching tail right?

No first hand experience, but the F2 has a reputation for eating valve guides prematurely. Honda changed the valve angle on them to produce a little more horsepower but in the process, spoiled it for making a lot more horsepower reliably or at least with some longevity. A big cam and more RPMs would not be a good thing.

The fix is to convert the F2 back to a K cylinder and head. Not enough K2s were ever sold for it to be a problem for Honda. I think they fixed a few under warranty, then soon introduced the DOHC and the F2 was history.

If I was going to choose an engine to soup up, i would not choose an F2

[MRieck]

So what's the joke on F2's?  Those were the late 70's models, with the tank color-matching tail right?

No first hand experience, but the F2 has a reputation for eating valve guides prematurely. Honda changed the valve angle on them to produce a little more horsepower but in the process, spoiled it for making a lot more horsepower reliably or at least with some longevity. A big cam and more RPMs would not be a good thing.

The fix is to convert the F2 back to a K cylinder and head. Not enough K2s were ever sold for it to be a problem for Honda. I think they fixed a few under warranty, then soon introduced the DOHC and the F2 was history.

If I was going to choose an engine to soup up, i would not choose an F2

I can't completely agree about not using the F2 engine as base motor to hot rod. The head does have problems but there are some good points. It has the newer style clutch setup and the output shaft is very beefy compared to the K's and F's. The case casting are nicer and heavier than early pieces. The cylinder is more stout. The cylinder studs are about 1mm thicker. The cranks were supposed to be better than earlier cranks as well. By better I mean material wise. I know when removing the galley balls and tapping for threaded plugs the F2 crank metal is harder than early cranks. You can feel it when turning the tap handle.

[MCRider]

So what's the joke on F2's?  Those were the late 70's models, with the tank color-matching tail right?

No first hand experience, but the F2 has a reputation for eating valve guides prematurely. Honda changed the valve angle on them to produce a little more horsepower but in the process, spoiled it for making a lot more horsepower reliably or at least with some longevity. A big cam and more RPMs would not be a good thing.

The fix is to convert the F2 back to a K cylinder and head. Not enough K2s were ever sold for it to be a problem for Honda. I think they fixed a few under warranty, then soon introduced the DOHC and the F2 was history.

If I was going to choose an engine to soup up, i would not choose an F2

I can't completely agree about not using the F2 engine as base motor to hot rod. The head does have problems but there are some good points. It has the newer style clutch setup and the output shaft is very beefy compared to the K's and F's. The case casting are nicer and heavier than early pieces. The cylinder is more stout. The cylinder studs are about 1mm thicker. The cranks were supposed to be better than earlier cranks as well. By better I mean material wise. I know when removing the galley balls and tapping for threaded plugs the F2 crank metal is harder than early cranks. You can feel it when turning the tap handle.

The risk one takes when talking about something I don't really know about is to look foolish.

Another side effect is that someone will take pity and teach me something. Thanks!

[Honda?]

So the F2 has valve guide problems but what about the F1 engine???

Does the F1 have any problems that stick out?

[MRieck]

So the F2 has valve guide problems but what about the F1 engine???

Does the F1 have any problems that stick out?

Aside from age.....no.

[SOHC Digger]

I can't say much about the Ebay add, but I did have some machine work done by these guys when I lived in Arizona.  The name of the shop was (and maybe still is) Short Block Charlie's.  I had my 750 block machined for an 836 kit by them.  They seemed to mostly deal in Harley, but as soon as I set the cylinder block on the counter, the guy said "CB750, huh?"  Now for a Harley shop to recognize one Japanese four cylinder block against another, they must have some decent knowledge.  The price was right for me, $40 a hole, $160 for the whole job with about 3 days turnaround.  I have not had any problems with the cylinders.  So, if you are interested, maybe give these guys a chance and call them to find out the real deal.