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Should i or shouldn't i

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Super1302 Officially Full-On Dubber

361 posts · joined Jul 2008 ·

#908200
got some cb cnc 043's with 40 x 35.5 single springs.
thing is i am running a 2332 with engle fk10.
is this combo appropriate. will be using on the street and maybe strip/circuit once a year.
i have a gut feeling i should be using dual springs and maybe should change to cb 044 mini wedge ports.
i am not sure they go cheap on the springs, valves and retainers in the heads i have as i have read that after 5000 miles that the valve train needs swapping out.
i like my torque and i wont be seeing past 7000rpms.

any ideas

sander288 "Bolt-on Master"

1,404 posts · joined Aug 2008 ·

#908212
The only issue I see with using the 043's is they have less meat to do head work with; careful with the dual springs too because you don't want to waste HP on pushing overly heavy springs you've got to balance between controlling the valve and energy required to push.

Changing to a better flowing head too will require some more compression and cam to make it really work; going to the wedge ports you might find you loose the bottom end a bit.

Cheers

Shaun
BMW R65 LS
1967 1300 Deluxe
Swing-axles FTW ❗

matberry Moderator Go hard or go home

8,114 posts · joined Mar 2006 ·

#908220
First....the springs, my opinion, your on the money, not enough spring for me, I like a lot a'la Berg.
I'd fit Scat or Berg Duals, but then the CB single groove retainers throw a spanner in the works as they don't interchange without either replacing valves to better quality Manleys or at least matching the keepers to retainers that come with the springs, or modifying the CB retainers for the duals.

I do like using the 043's as they are a way better casting IMO with way more cooling air passages which for a street engine I feel is very important, but there is always a trade off. The thicker 044's offer more material so for a heavy load application (turbo, bus towing, race...) they are possibly more stable due to shear bulk of the casting.

The bigger heads will need way more cam and comp, which will be more rpm/power overall, as to loosing bottom end, you gain it back with cr and more top end, but all is not equal.... exhaust and carbs will also play a part with the differences between the two.
Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
OFF-ROAD,CIRCUIT,DRAG,STREET,ENDURANCE

Super1302 Officially Full-On Dubber

361 posts · joined Jul 2008 ·

#908227
i have enough cam and the 44 idf's are good, 48's will out perform at higher rpm's, i dont need high rpm. Useable hp and torque for me 🙂
i wonder why cb went the way they did with their single retainer, single spring idea. aahh.
so new springs, valves, retainers and machining for dual's = $ and actually the heads are no good for fk10 with 1.4 rockers😢 i guess
thats another reason to move away from the 043's. shame though.

psimitar Son of Jim - Creator of Good

2,506 posts · joined Jan 2009 ·

#908294
shouldn't Engle have a recommendation for the springs to use including overall spring ratings?

Not built such a large HP engine meself but I'd be following the manufacturers spec when it comes to cam. Is it meant to run with ratio rockers?

The Samba is also great for finding info on HP engine builds 🙂
madness is in the eye of the beholder 👍

hellbugged 48's and straight cuts

5,080 posts · joined Apr 2003 ·

#908305
As per Matty. Valve control reigns supreme for longevity and performance, no way i'd be using single springs.

More in it than just swapping out heads unfortunately.

matberry Moderator Go hard or go home

8,114 posts · joined Mar 2006 ·

#908330
Psimitar, I here you, but not all manfacturers are correct in thier specifications/recommendations as they unfortunately dont always have longevety in mind, so research is definately required. Even the forums are only a tool, sure check out opinions, but even they need to be reflected on. Not every post is correct. People can say they have no problems yada yada......in the case of engines, how many actually check inside once built, how many actually achieve 100 000, 200 000 or even 300 000 miles???????
Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
OFF-ROAD,CIRCUIT,DRAG,STREET,ENDURANCE

psimitar Son of Jim - Creator of Good

2,506 posts · joined Jan 2009 ·

#909695
matberry wrote:Psimitar, I here you, but not all manfacturers are correct in thier specifications/recommendations as they unfortunately dont always have longevety in mind, so research is definately required. Even the forums are only a tool, sure check out opinions, but even they need to be reflected on. Not every post is correct. People can say they have no problems yada yada......in the case of engines, how many actually check inside once built, how many actually achieve 100 000, 200 000 or even 300 000 miles???????
Yea, is hard especially when dealing with an engine that only made 50bhp at it's largest size. Would a professional engine builder know? Or would you have to ask the old gasser engine builders in So-Cal for their experience?
madness is in the eye of the beholder 👍

matberry Moderator Go hard or go home

8,114 posts · joined Mar 2006 ·

#909696
Don't ask me, I'm biased.
Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
OFF-ROAD,CIRCUIT,DRAG,STREET,ENDURANCE

psimitar Son of Jim - Creator of Good

2,506 posts · joined Jan 2009 ·

#909699
matberry wrote:Don't ask me, I'm biased.
Biased. Why?
madness is in the eye of the beholder 👍

matberry Moderator Go hard or go home

8,114 posts · joined Mar 2006 ·

#909709
I build what I describe as quality engines....... 🙂
Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
OFF-ROAD,CIRCUIT,DRAG,STREET,ENDURANCE

vwo60 Veteran Volks Folk

2,036 posts · joined Feb 2007 ·

#909710
You can send the cam to a specialist that can run the cam and tell you exactly the spring to run with it, this way you can use a spring that that has the lowest seat pressure to do the job, i know a turbo engine that is running single conicial bee hive springs to 7000RPM with no float.

psimitar Son of Jim - Creator of Good

2,506 posts · joined Jan 2009 ·

#909746
matberry wrote:I build what I describe as quality engines....... 🙂
Like 🙂
madness is in the eye of the beholder 👍