"Benefits" of doweling..

Mir · January 05, 2011, 09:58:39 PM

Hi Guys

I am aware about the benefit and draw backs of the Doweling..I have read the post of Rice Racing on RX7 Club and read many thoughts on doweling on Aussi forums... I want know what our club members thinks of a dowelling?? Someone was saying to me I should go for studs not doweling and someone was saying that doweling is not needed...

I am going with my builder/tuners advise as I have a complete faith in the advice of my builder and tuner:god, and there is no way i ever thought that i would go against it..However, I would like to see how many people share the same thoughts as his.. and how many people divert from that advise

Cheers
Syed

Mir · January 05, 2011, 10:04:39 PM

I am looking for general perception about doweling...everyone is welcome to comment..

Regards
Syed

Grant Monkhouse · January 05, 2011, 10:23:42 PM

From what I understand. Doweling is not really needed unless your running 1000HP plus.
I can only think that you would need doweling if your running huge boost or high rpm or both?

Mir · January 05, 2011, 10:56:35 PM

I share the same thoughts as above
cheers

Brett · January 05, 2011, 11:11:49 PM

Surely its more dependant on the amount of torque being generated, plus the pressures within the chambers.

I belive Kev constructed his tripple with a quarter inch plate across the base.. i imagine that would go some way to address any force moments... :Giggle

Grant Monkhouse · January 05, 2011, 11:43:02 PM

Quote from: Brett;735356Surely its more dependant on the amount of torque being generated, plus the pressures within the chambers.

I belive Kev constructed his tripple with a quarter inch plate across the base.. i imagine that would go some way to address any force moments... :Giggle

Yes I believe he did and it is by far the cheapest, easiest thing to do. And as I hope keV should easily crack the 1000HP with his monstrous setup?!

High rpm would be the part of the equation for the increased force moments?

I think doweling or quarter inch plating an engine is only going to be beneficial however you look at it. It\'s just a case of do you want to pay for it.

I would use the plate method for cost personally if I was looking for those type of HP numbers but if had a triple I would look at doweling and getting dry sumpped, if it was a racing car that is and I wasn\'t concerned about cost

Mir · January 06, 2011, 12:09:41 AM

Who is keV guys new to me??? Since u guys know I have triple, I was told to get dowling done..I don\'t know whether people wud agree with me or not but when a sever detonation occurs, nothing stops engine from twisting- whether it b a doweled or stud engine..so conclusion can b that doweling does not eliminates complete twisting but offers little protection against twisting??

Wud u guys agree??

Syed

Prof · January 06, 2011, 07:20:45 AM

If you make something stiffer, then it must be less prone to twist. The point is, when you get detonation, that force has to go somewhere. Usually that\'s apex seals, but with the new twist rather than break seals that we see more and more of, they will let go gently without cracking and taking housings with them.

I could see a situation occurring when an engine bombs so bad that it will actually crack the housing or iron, finding any weekness that\'s there.

On the FC blocks, they mount in the middle, so there is a large twisting force when you take off from a standing start, through the gearbox / bellhousing and applied on the rear half of the engine. The rear irons received some modifications around the oil pedestal as this dowell seat was a weak point.

I guess if your engine builder is recommending it - go with their decision.

BlitzBoy · January 06, 2011, 10:30:20 AM

Depends on power levels, boost pressures, fuel being used, tuning etc etc, but remember Ross\\Dragon with his undowelled 13B cracked 9.1 at the high end of 150 terminals.

Personally IMO anything up to 600bhp you dont need dowelling or Studs.
Plenty of cars in the US doing 9 sec quarters and over 140 terminals with no doweling or studding.

If your engine builder has experiance of producing high power rotaries that have achieved low ETs and high terminals on the drag strip go with the advice of your engine builder.

I have thick baffle plate mounted between the keg and the sump pan to help stop the twisting force, made by Reworx

DRAGON · January 06, 2011, 12:24:29 PM

I dont know much about dowelling, never needed to do it myself.
But I know back along Carl Hayward used to say that any engine using more than 1 bar of boost had to be dowelled, you maybe able to find some old posts about it on here.

mx1311 · January 06, 2011, 12:53:57 PM

ill agree with ross here

imho by adding extra dowels you are reducing strength of the irons as you are removing material to allow the dowel to be fitted

oversize studs create the same problem and if tolerences are too tight plates will crack at the slightest bit of det (which you always get when tuning a car to extremes where you think studs and dowels will be required)

last motor i put together was for rob and is still going strong at 1.8bar of boost and 700+hp and has no dowel\'s or oversize studs, 100 odd dyno pulls and countless low 10\'s

Grant Monkhouse · January 06, 2011, 05:35:48 PM

Quote from: DRAGON;735429I dont know much about dowelling, never needed to do it myself.
But I know back along Carl Hayward used to say that any engine using more than 1 bar of boost had to be dowelled, you maybe able to find some old posts about it on here.

Ross did you end up bending/twisting your e-shaft when trying to beat your time?
I can\'t remember where I read about that, may have been on one if your max power features?

DRAGON · January 06, 2011, 05:39:55 PM

It was at TOTB on a very hot day, I believe it was down to oil temps more than anything, and yes the shaft did bend and take the engine out, only time it ever blew.

Grant Monkhouse · January 06, 2011, 05:40:14 PM

Would everyone agree that 1/4 inch plate would be more beneficial to Mir\'s needs?

Instead of taking material out of the engine components, he would be adding material onto the bottom of the block to stop any twisting?

Grant Monkhouse · January 06, 2011, 05:42:38 PM

Quote from: DRAGON;735493It was at TOTB on a very hot day, I believe it was down to oil temps more than anything, and yes the shaft did bend and take the engine out, only time it ever blew.

That\'s some seriously impressing thing to do though! I would have kept it as a mantel piece ornament to show people what can happen.

How long did you run the standard box for?