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Romac Harmonic Balancer
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Author:  jester99 [ Mon Mar 01, 2010 7:36 pm ]
Post subject:  Romac Harmonic Balancer
Made some enquiries today into a romac harmonic balancer. My 1100 just has the standard pressed steel pulley and i have read and understand the mini engine is under-dampened with regards to the crankshaft etc.

I got a call back stating romac is no longer supplying this balancer for A series engines at all due to many high rpm failures. Initially i understood this was due to a manufactur issue but the sales person went on to tell me that apparently quite a few mini engine builders take their engines over 9000rpm and that the romac balancer is not designed with this rpm i mind and as such has taken them off the market until such time that they (romac) and these engine builders come up with a positive result.

i didnt think many mini engines were reved that hard! 9000rpm is pretty crazy stuff i thought.

Is this normal? how many people rev there engines this high? Am i being told a story or what?

In the past i have used and fitted quite a few romac balancers to V8 and 6cylinder engines both road and track. never heard of this before.

what should i do with regards to a harmonic balancer? does anyone have some input for me?

thanks guys.
Author:  74snail [ Mon Mar 01, 2010 7:45 pm ]
Post subject: 
Cooper S one is the most recommended, there was an epic thread which went nuclear about damper failures ( cough Romac cough ), nearly every time they get mentioned there is a loud creaking noise as the can of worms gets opened
.
Author:  drmini in aust [ Mon Mar 01, 2010 7:45 pm ]
Post subject: 
Contact http://rossperformanceparts.com/
They repair old 1100/1275 harmonic balancers and (I believe) now make new ones.

Or buy one of these like I did, you also need the hub shown for it.
http://www.minis.com.au/minis/catalog/p ... cts_id=912
and
http://www.minis.com.au/minis/catalog/p ... cts_id=927
Author:  jester99 [ Mon Mar 01, 2010 7:48 pm ]
Post subject: 
rightio. i see hmmmm. ok so definatley dont use a romac on an A series engine then?

Can anyone suggest a better balancer?
Author:  drmini in aust [ Mon Mar 01, 2010 7:49 pm ]
Post subject: 
see my edit above.
Author:  jester99 [ Mon Mar 01, 2010 7:51 pm ]
Post subject: 
As usual Drmini you have been very helpful. thanks :D
Author:  awdmoke [ Mon Mar 01, 2010 9:08 pm ]
Post subject: 
Still using a liRomac lightweight damper on my 1430cc stroker, revved to 7800 sometimes on track days.
Still happy with it.

If I ran it to 9000 I would only blame myself.
Author:  jester99 [ Mon Mar 01, 2010 9:13 pm ]
Post subject: 
i thought that was pretty extreme rpm for a mini engine.

i dont plan to rev my engine anywhere over 6500rpm and as such expected that i should be able to buy one of these balancers and operate it without any trouble. But according to romac they are removed from sale.

oh well, i will just use a different brand.
Author:  sgc [ Mon Mar 01, 2010 9:25 pm ]
Post subject: 
Send a PM to BALLISTIC and ask him what he thinks of Romac balancers ;)

The rubber in his balancer departed company not far south of Gundagai last year on the Asparagus job...
Author:  drmini in aust [ Mon Mar 01, 2010 9:28 pm ]
Post subject: 
If it's just a road motor, I'm sure someone has a good s/h 1100 one here. :wink:
Author:  BALLISTIC [ Tue Mar 02, 2010 11:27 am ]
Post subject: 
Stick to the good ol' cooper "S" balancers . . . My previous engine had one of these balancers on it for less then 12 months . . . only a road motor and didnt see over 7,000 rpm . . . spent most of its life between 3,000 and 6,000 rpm. The outter started spining on the inner probably about a month after I built the engine, it made a "loose fan belt sound" when a largish electrical load was put on, used to go away for awhile when I tightend the belt . . . anyways it shite itself on the way back from QLD last year and i had bugger all oil pressure after that . . . anyways dont do it, it ain't worth the trouble.
Author:  miniDave [ Tue Mar 02, 2010 11:31 am ]
Post subject: 
I called Ross from 'Rossperformance' about a dampner about a month back. He was prepared to dig around for one and mentioned he would consider keeping regular stock in there was a need for them. He will do the two types. Before going this far Mr GR managed to fine me a good second hand one.
Author:  TheMiniMan [ Tue Mar 02, 2010 12:45 pm ]
Post subject: 
Ive always (tried to) use new , or otherwise good condition 2nd hand Cooper "S" ones on all my race motors & i`ve always been very happy with them,,, (until recently) having them balanced with the entire reciprictaing mass is VERY important tho

We fitted one of the Std "S" ones to our turbo twin cam moke, but it shat itself after the Qld mini Car club Christmas party last year

now that`s the very first one i`ve ever seen (or heard of) let go,,, however, we must all now realise that these things are verging on the possibility of being approx 40-ish years old,,, so don`t think the std "S" ones are un-breako,,,ok?

In saying all that tho,,, we did spin that donk to some stupid revs , & for quite some time too :-)

MY own personal, (first ever) 1415cc stroker full race engine that i build when i was 16 years old was set up to run at 8000rpms & after setting up the f/d gear ratio to suit the track , we decided it was a little zippy cause we ended up pulling 8500rpms on our taco,,, so after a little chat with my dad about the (slight) over revving he suggested that we tall-up the f/d ratio to drop the revs for safety sake, (but i didn`t change it) & he (eventually) came to the track to watch (& of course he wanted a drive too) BUT!!!! after that he suggested it was running more like 9000rpms & the taco was out,,,

so we had it checked & he was wrong,,, when my taco was saying 8500rpms it was actually doing 9200rpms :-) Lots of tacos don`t read accurately so have yours checked if you have any doubts

this race donk had a 2-piece "S" pulley, 1415cc stroker, 60-80 cam, 520thou valve lift , with one of my own cyl head-jobs, Super big long 3-into-1 full race 9000rpms extractors on it & a 45mm weber withvery long inlet trackt & LOVELY Bell-mouth ram tubes etc etc etc... now this engine was re-built every year (approx 40-odd race meetings each year, with normally 3 races nearly every saturday night & quite a number of other race meetings thrown in on some sundays at places like Echo Valley etc as well,,, so, at the end of every season, it was usually a quick re-ring & bearing, clean up the valve seats & re-new a few gaskets-n-seals , whack it back together & fang the crap out of it for another year, again & again & again,, so this poor old race donk constantly saw 9000rpms , for about 9 years solid

The pulley off that engine is what we fitted onto the turbo twin cam moke,,, & it`s shat itself late last year

so it`s not just romac balancers that give-up from the over-rev problem,,, any of them can do it if taken past their recomended rev for any length of time

But the std (2-piece) "S" ones are damn hard to beat .
Author:  Brown Clubman [ Tue Mar 02, 2010 3:11 pm ]
Post subject: 
BALLISTIC wrote:
Stick to the good ol' cooper "S" balancers . . . My previous engine had one of these balancers on it for less then 12 months . . . only a road motor and didnt see over 7,000 rpm . . . spent most of its life between 3,000 and 6,000 rpm. The outter started spining on the inner probably about a month after I built the engine, it made a "loose fan belt sound" when a largish electrical load was put on, used to go away for awhile when I tightend the belt . . . anyways it shite itself on the way back from QLD last year and i had bugger all oil pressure after that . . . anyways dont do it, it ain't worth the trouble.


hmmmm .... interesting.....

My GT has a Romac fitted and I've noticed recently a slight "squeek" coming from the fanbelt/HB/Water pump area. It mainly happens when the engine is cold and running rough(ish) or about to stall. I wonder if this is a Romac issue? Is there any way of checking it? Last thing I want is for it to crap itself on the freeway somewhere.

What did you do when it happened on the way back from QLD scott? What's the damage potential when they let go?
Author:  sgc [ Tue Mar 02, 2010 4:27 pm ]
Post subject: 
Brown Clubman wrote:
What did you do when it happened on the way back from QLD scott? What's the damage potential when they let go?


He sent me a text at 5am (as we were gearing up to leave Wyong) and we made a flying visit to Mini King on the way past, and made an express rescue run to Gundagai :lol:
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