B1 Engine build... decisions, decisions, decisions....

[DCRocks]

So for my winter project, I am building a new engine for my blaster.

I have read through endless threads on all the choices, and this has left me more indecisive then at the start.

I currently have a workign 61x engine to start with, know I want to stick with a single carb, use my RIVA girdled head, and my factory B limited pipe.

I am going back and forth between buying a 62t case and single carb intake, and using my 61x cylinder (with a bore to .50 over)

Or, I can have my 61x cases and Cylinder ported, and build around them.

The only basics I am sure of, is running a single carb, running 81mm, 50 over pistons.

The cost is more for the 62t engine, but it seems that in the end, the 62t makes more power, with the same setup. (ie head, piston size, etc)

With everything being equal, is the 62t as reliable as the 61x?

If I am willing to spend the extra, will the difference in the engine be truly noticable?

Should I just save the money I would spend on the 62t case and intake, and bore and port my 61x case and cylinders?

I am trying to build a surf ski, if that makes a difference, not a race ski, and a bottom end / mid range punch is my main goal.

From all I can tell, if I go the 62t route, I will be ahead in the end, as the intake would be a perm upgrade (reusable), and it seems a stock 62t case, is better than a ported 61x case, though I might be off base here.

I look to spend from $500-800 either way, maybe a bit more, and was trying to determine where the best end results could be acheived.

[SJKny]

stick with the 61x cases and build the "frankenstein" motor. i.e. 62T(760) cyls. Maybe a bigger carb, light flywheel, and milled head or ADA. You got the pipe so all this can be done with little investment.

[DCRocks]

stick with the 61x cases and build the "frankenstein" motor.

I kinda like that build concept.

I think I would need the following to complete it:

1) Get a 760 cylinder

Will this need to be ported/bored to work with the 61x case?

2) the 61x case ported to match the 760 Cylinder

I was under the impression the 61x case will need modded to accept the 760 cylinder. Is this the case? If yes, any specifics as to what need done, or recomendations as to who to get to do it?

3)Mod the current RIVA Girdled head I have

Can I just change the 81mm/35cc domes, or do I need some other mod?

[LBE]

I was in your position about a year ago. Here's what I did:
62t cases
760 cyl
single 44
stock light flywheel
limited b-pipe

RRIIIPPSSS!!
I really think the B1 needs a 760. Dunno how a 760 on x cases runs, but for $200 you can get a set of t cases. To make a 760 fit on x cases you have to bore the case where the sleeve slides in. You can actually do this yourself with a dremel or grinder, it does not need to be perfect, or any local machine shop should be able to do it cheap.
Don't bother porting the cases.
I just picked up a ported 760 cyl for $150, and one just went on ebay for $100. I paid $300 for my ported 760 (currently in my ski) and that came with pistons.
IMO: get some t cases, keep your x electronics, get a 760 and have it port mached or find one done. With your budget and with what you have, you should be able to do it with in budget.
For the head, I just bought 760 domes for my R&D head. Or get a stock 760 head and mill it.

3 of the Local B1 guys are now running similar 760 set ups. Even a bone stock 760 motor with the b-pipe runs great.

[Big Kahuna]

I have a complete 760 motor if your interested........ Carbs and electronics available also.........

[DCRocks]

I have a complete 760 motor if your interested........


thanks but gonna pass.

I am really looking to just pickup a 760 cylinder, and get it fixed up.

[WaveDemon]

I've got a 86mm frankenstien motor I could let go.

[DCRocks]

Nice, except I kinda dont need the whole thing. I have two whole 61Xs to build upon, just need to upgrade the cylinders.


Now, if you are willing to part with it in the 400-500 dollar range... that might be a different story...

:haha:

[yamahammer]

760t on 61x cases is a good torquey engine good bottom end hit, but not a lot of topend- i had that on my blaster first- then got a dual 44 61x intake and it really woke up- dual carbs will get you more topend- i wouldnt spend the coin on 62t cases unless your going to upgrade intake, and reeds (highly recommend vforce2- really gets engine revving quickly)- otherwise stick with 61x- you already have it- just dremmel out cases- if you have the cash get 62t and every thing else you can afford- makes blaster much funner with more power and for me (fatboy) easier to hop up on

[DCRocks]

Ok, so I picked up a ported 760 Cylinder, that the seller told me was ported for freestyle by Rick Roy.

Just found out who he was!!

Rick Roy
home town: Coteau Du Lac, Quebec, Canada
years riding: since 1990

Contests/achievements:
pulled the first-ever backflip on a stand up pwc!
Freestyle National Champion 1995-1998
Freestyle World Champion 1996-1998

Very Cool!!

I also have a dual R&D intake manifold for the 61x case, and a matched set of SBN 44 carbs.

I REALLY want to stick with a single carb though, so is there a better option for intake manifold & reeds than the stock one?

Or is there a way to dremmel out the stock ones to improve their performance?

[SurfCrazed]

I REALLY want to stick with a single carb though, so is there a better option for intake manifold & reeds than the stock one?

Or is there a way to dremmel out the stock ones to improve their performance?
keep the 61x cases port them out and stick a 48mm carb on there! use the link i gave you on wavejunkies on how and where to port! or i can do it for ya!