Bridgeport?

[MikeLMR]

What are the pro\'s and cons of a bridgey against say a large street port that had been suggested as being the best option earlier on ?

For example you are introducing another failure mode to the engine, how long is the bridge going to last before it fatigues and cracks (suppose this depends on the port at the end of the day)  The rotor hosing will require a chamfer to allow the eyebrow port to flow and doesn\'t this decrease the amount of metal near the water seal, yet again this dependant on the port I think.

This is from my limited knowlege of all things rotary so feel free to correct me and to continue with some pro\'s and cons so that Roundabout-now can make the right decission and we can learn a little more about what to consider when porting an engine.

Mike

[antnicuk]

those from down under also forget that we pay 1 GBP a litre of fuel, thats 2.67 AUDs, how does that compare to what you pay?

apart from that faster the better!!!

[Carl]

A mild bridge port should be no more unreliable than a major extend except for the fact that with more possible power the motor will be under more strain so life will be reduced.
If the bridged engine is N/A then more revs will be used and also reduce the life of the engine.
I think that the the type of things that need to analyzed as an overall package are what sort of power,longevity, type of use,and cost should also be all taken into consideration.
If these can be balanced then a good decision could be made.
Allways budget for considerably more expense than originaly worked out though, and you won\'t go far wrong.
When I speak of reduced engine life I offset this by saying that you can keep a good powerful engine going by refreshing it before it goes wrong,a regular compression test will help in this regard.We need to get into that sort of mentality in the UK on powerful rotaries.Think of them as race engines which get pulled apart often for a once over.
Kind regards
Carl

[antnicuk]

Carl,
Dave and I have said we will try and do this,  the only thing is that gasgets and combustion/water jacket o rings are not cheap here even if you could re use apex/corner/side seals.   If you were working on your own engine what parts would you try and re use if cost was a factor.  
Am i right in thinking that by \'refreshing\'the engine you are saving on damaged rotor and rotor housing should it pop?

I have been told that oil control ring rubbers should be replaced every time, is this true if they have only done 2.5k miles.
One other thing, is it a problem to mix and match apex seals with new / part won ones?

regards

tony

[Carl]

Hi Tony
The oil control "O" rings will probably be ok.
I recomend to use new apex seals because you don\'t know if the old ones even though the mileage is low have been stressed ( but are still intact at the moment), from detonation.Especially since your engine popped.
The water seals should be replaced.
Refreshing the engine keeps everything in tip top condition,remember that as soon as you start an engine it starts to wear,if you have built your engine properly and it is putting out alot more power than standard it will wear quicker, so a refresh before something major goes wrong is good preventive maintenance.Of course that also means that more parts will be reclaimable from the engine for each build.
If it was my engine I would reuse the side and corner seals if they were not worn too much,you will have to measure them.The rubber inserts on the corner seals can be replaced.
Kind regards
Carl

[antnicuk]

Thanks for that Carl,
Do you have any opinions on the solid corner seals, (no rubber grommet)?  also you mention that i should change the water jacket ring, but what about the combustion ring?

I have just seen for sale a set of end plates and centre plate for a 13b, which were ceramic coarted, have you heard of this and is it any good?

many thanks and regards

tony

[Carl]

Originally posted by antnicuk
Thanks for that Carl,
Do you have any opinions on the solid corner seals, (no rubber grommet)?  also you mention that i should change the water jacket ring, but what about the combustion ring?

I have just seen for sale a set of end plates and centre plate for a 13b, which were ceramic coarted, have you heard of this and is it any good?

many thanks and regards

tony

Hi Tony,
Not sure if  you mean the inner water seal but all of the water seals need to be replaced.
The end plates that are nitrided,or stock are more than fine,I don\'t think ceramic coating is a good idea.
Racing beat have tried it and come unstuck when the ceramic coating peeled off.
Kind regards
Carl

[BUZNUTS]

Hey,
Listen to Carl he is giving you the correct advice. I know many people to try and re invent the surface hardness of a plate and nearly all of them end in grief.
REgards-Anthony

[igy]

The one and only drawback to the secondary bridge in my experience is the damn COPS.  If done correctly they are very loud and the police WILL be waiting for you if you drive it on the street.  I would still have a bridge motor in my car today if I didn\'t have to worry about getting pulled every time I drove it on the street.  If you do it, it will be in your dreams forever!  I can feel my heart beat faster everytime I think of it.  The rocking of the car and that distinctive Brap Brap Brap Brap!  The look on the snot nosed T78 big cams with daddy\'s money GTR driver when you smoke his ass out the hole and then proceed to put 5 cars on him by the end of 2nd gear.  The proud feeling you get when you twist output shafts on trannies, break axles, snap ppf\'s and blow diffs on the ground on the street and you\'re only boosting 19psi.