How should I progress with engine rebuild?

stuart wizy · October 30, 2006, 10:06:51 PM

ive just bought original water seal kits from mazda and used everything else from rotary resourses.
3mm tips can take a little more det than 2mm but dont seal as good or so they say.
im only using 3mm tips in the fc drag car because it will be taking a lot of stick with high boost from a t45 and just thought it would make it a little stronger when passing over huge exaust ports where theres not much surface area suport for the tip.
just gives me more confidence its not going to pop with solid corner seals and 3mm tips, and i can mill them out myself which helps.

antrosser · October 30, 2006, 10:11:44 PM

ive got a big turbo, NOS and drive it hard too, but been advised to stick with the 2mm. other cars of this spec perform well with the 2mm so i thought why spend the extra money! lol. dont want my engine to go bang tho :-(

Grizzly · October 30, 2006, 10:36:35 PM

Quote from: stuart wizy3mm tips can take a little more det than 2mm but dont seal as good or so they say.
im only using 3mm tips in the fc drag car because it will be taking a lot of stick with high boost from a t45 and just thought it would make it a little stronger when passing over huge exaust ports where theres not much surface area suport for the tip.
just gives me more confidence its not going to pop with solid corner seals and 3mm tips, and i can mill them out myself which helps.

Ok, that does\'nt make sense, I can understand how you think they are stronger is a common Misconception but do you think the Extra weight is going to help at high Rpm/Load going over a Big exhaust port? If it is staitionary i could Understand why some one would think a bigger thicker seal is better but add Rpm and the centrifugal force will increase the more Weight you add so in turn the more force it will apply to the Housing so in a High HP application the Apex\'s stand more risk of it Pushing so hard it has no Lube between the seal and Housing also causing extra Friction and as you say possably pushing into the Exhaust Port. You want to go Lighter not heavier, ceramics and get it well set up. There are also well known people using Big exhaust ports and 2mm mazda seals in very fast Sevens.

Grizzly · October 30, 2006, 10:38:32 PM

Quote from: antrosserive got a big turbo, NOS and drive it hard too, but been advised to stick with the 2mm. other cars of this spec perform well with the 2mm so i thought why spend the extra money! lol. dont want my engine to go bang tho :-(

TBH i\'m not a fan of NOS its Unpridictable but there are people out there Running it but if you have a Decent Single Turbo and Run around 400 you aint ever going to Use NOS its a Gimic

stuart wizy · October 30, 2006, 10:45:46 PM

If you look at whats going on in the states and in australia most of the rebuilds use 3mm seals, like grizly says though u can always use your rotors on a rebuild even if your slots have worn over tolerance , ie there never scrap, just mill them out or buy new rotors! which is cheapest then?
why are all the top apex seal producers making 3mm tips all over the world?
ive never herd of anyone with a motor running 3mm tips in the uk, correct me if im wrong but knowone ever talks about them.

88GT-R · October 30, 2006, 11:01:35 PM

Hi,
I run 3mm steels. I was running 3mm ceramics, until one cracked. I regret using 3mm, as i can not safely run high rpm. I have so far only run her upto 7500 on the dyno, where power is still climbing at a 50 deg angle and not peaking. If you have a good map, 2mm are good.

J

stuart wizy · October 30, 2006, 11:12:22 PM

grizly mate, i would love to go ceramics but have u seen the price!!
this motor is being built cheap with second hand rotor housings with 4 cnc milled bridge ports and a totaly custom inlet runner and plenum that u wont find anywhere cause its my own idea, the inlet ports are nearly a 1/4 bigger on each side housing and its got 4 - 50mm tube runners feeding them bolted straight onto the engine with a milled out matched inlet manifold.
I dont even know if its gonna work yet, it might not even wanna rev cause the air speeds to slow through the runners.
If it does work though this motor has the potential to make some serious power and then I can start thinking about carbon and ceramic tips when its proved itself.

88GT-R · October 30, 2006, 11:20:36 PM

Stuart, having an engine which will potentialy make its power upwards of 8grand is great. You will not be able to realize that power with 3mm steels. 3mm ceramics will do the job, and are fantastic. NRS ceramics are not that expensive as far as ceramics go.
Cheers,

John

Grizzly · October 30, 2006, 11:22:54 PM

Ok use stock Mazda seals then.

Ceramics are the last great Hope of the Rx World but Mazda OE seals are the Back bone. If i was building a Big HP engine Tomorow i\'d use OE 2pc 2mm Seals. Its funny i have a set of 2mm ceramics for my triple and i am seriously thinking of selling them to use stock 2mm\'s (Not Joking) Every one who is anyone uses OE seals in the Big motors if not they have Ceramics but the only 3mm\'s you will see will be Ceramics.

Grizzly · October 30, 2006, 11:29:17 PM

Quote from: stuart wizyIf you look at whats going on in the states and in australia most of the rebuilds use 3mm seals, like grizly says though u can always use your rotors on a rebuild even if your slots have worn over tolerance , ie there never scrap, just mill them out or buy new rotors! which is cheapest then?
why are all the top apex seal producers making 3mm tips all over the world?
ive never herd of anyone with a motor running 3mm tips in the uk, correct me if im wrong but knowone ever talks about them.

Thats it in a nut shell, 3mm seals are for Over Tolerance Rotors, all the Top Apex seal people make them becouse of this reason.

People think there Stronger becouse there Thicker it don\'t work like that in High RPM Motors.

stuart wizy · October 31, 2006, 12:23:03 AM

got any info or links for 3mm ceramics then guys?
why did your ceramics chip then john? and why cant u run higher than 7500rpm?

How should I progress with engine rebuild?

88GT-R

88GT-R