Got my new engine today!!!
Thread Starter
I am the Anti-Ch(rice)t
Joined: Nov 2001
Posts: 1,363
Likes: 0
From: Savannah, GA
Got my new engine today!!!
Mazdaspeed7 and I pulled an engine out of an 86 sport today with 120000 miles on it. now i get to mod the entire thing. any suggestions on things other than basic rebuild and porting, to the actual block.
Justin
Justin
mad scientist
Joined: Feb 2001
Posts: 2,665
Likes: 2
From: Savannah, GA
Justin, how would you like to be the guinea pig for some high compression n/a rotors? I was thinking about sending my extra pair to my uncle and have him fill the recessed part some to bump up the compression. I just need to figure how much displacement to cut to raise the compression up to lile 11.5-12.0 Every point increase is good for 4% more power, so 11.7 would make 8% more power than stock S5 n/a, and almost 10% more than S4 n/a rotors.
Ill have some pics of the engine tomorrow, along with pics of my hood
Justin paid ~$270 for engine, ECU/harness, coils, airbox/afm, and a few other little things. The engine appears to have decent if not good compression. It turns over easily, with very distinct puffs of air.
Ill have some pics of the engine tomorrow, along with pics of my hood
Justin paid ~$270 for engine, ECU/harness, coils, airbox/afm, and a few other little things. The engine appears to have decent if not good compression. It turns over easily, with very distinct puffs of air.
Thread Starter
I am the Anti-Ch(rice)t
Joined: Nov 2001
Posts: 1,363
Likes: 0
From: Savannah, GA
i dont like the term guinea pig. show me something to make me feel better about testing on my car.
would he fill it with ceramic??? i do like the idea but i need to see some other guys experiences with high comp rotaries. i would have to use high octane gas but i dont want to be pinging on citgo 94. that would suck. if i did that i woudl definitely get the hurley 3mm. i just dont want my engine to eat one. hmmm......
i wanna know how much power (ballpark estimate) a s4 street ported, 12.0 compression, exhaust port with full exhaust and cold air intake would make???
i want some opinions
Justin
would he fill it with ceramic??? i do like the idea but i need to see some other guys experiences with high comp rotaries. i would have to use high octane gas but i dont want to be pinging on citgo 94. that would suck. if i did that i woudl definitely get the hurley 3mm. i just dont want my engine to eat one. hmmm......
i wanna know how much power (ballpark estimate) a s4 street ported, 12.0 compression, exhaust port with full exhaust and cold air intake would make???
i want some opinions
Justin
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Joined: Apr 2001
Posts: 1,921
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From: Windsor, Ontario, Canada
Go with 3mm seals.
12:1 compression... Damn.
Is that a resonable figure?
I would look at some N/A race engines... seeing what compression they use.
With that kind of compression I would definately go with 3mm apex seals... You will be running a very high risk of detonation if you aren't running 100 octane all the time.
3mm seals can handle quite a bit of detonation- one good ping can break a 2mm, while a 3mm will take a LOT of abuse. Worth the insurance I think, though they can break, but you have to pretty much TRY to do it! They also seal better at high RPM's because of higher centrigugal force exerted outwards onto the housing by the seal.
Oh- and FD side springs- they are much better.
You need a milling machine for that though- the groves have to be perfect. Any machine shop would do it- rotary "specialty" shops charge a ridiculous amount, up to 800 bucks!!!!!!!! It is really just a very basic machine job, and should cost about 100 bucks or less, that's how I got mine done. Just another example of "specialty" overpricing.
As for HP figures, I really don't know, but with mild porting, and you'll want a BIG exhaust... Defnitaely over 200 at the flywheel. I definately wouldn't expect any lower than that, but I am not sure how much more.
Is that a resonable figure?
I would look at some N/A race engines... seeing what compression they use.
With that kind of compression I would definately go with 3mm apex seals... You will be running a very high risk of detonation if you aren't running 100 octane all the time.
3mm seals can handle quite a bit of detonation- one good ping can break a 2mm, while a 3mm will take a LOT of abuse. Worth the insurance I think, though they can break, but you have to pretty much TRY to do it! They also seal better at high RPM's because of higher centrigugal force exerted outwards onto the housing by the seal.
Oh- and FD side springs- they are much better.
You need a milling machine for that though- the groves have to be perfect. Any machine shop would do it- rotary "specialty" shops charge a ridiculous amount, up to 800 bucks!!!!!!!! It is really just a very basic machine job, and should cost about 100 bucks or less, that's how I got mine done. Just another example of "specialty" overpricing.
As for HP figures, I really don't know, but with mild porting, and you'll want a BIG exhaust... Defnitaely over 200 at the flywheel. I definately wouldn't expect any lower than that, but I am not sure how much more.
mad scientist
Joined: Feb 2001
Posts: 2,665
Likes: 2
From: Savannah, GA
Re: Go with 3mm seals.
Originally posted by Bambam7
12:1 compression... Damn.
Is that a resonable figure?
I would look at some N/A race engines... seeing what compression they use.
With that kind of compression I would definately go with 3mm apex seals... You will be running a very high risk of detonation if you aren't running 100 octane all the time.
3mm seals can handle quite a bit of detonation- one good ping can break a 2mm, while a 3mm will take a LOT of abuse. Worth the insurance I think, though they can break, but you have to pretty much TRY to do it! They also seal better at high RPM's because of higher centrigugal force exerted outwards onto the housing by the seal.
Oh- and FD side springs- they are much better.
You need a milling machine for that though- the groves have to be perfect. Any machine shop would do it- rotary "specialty" shops charge a ridiculous amount, up to 800 bucks!!!!!!!! It is really just a very basic machine job, and should cost about 100 bucks or less, that's how I got mine done. Just another example of "specialty" overpricing.
As for HP figures, I really don't know, but with mild porting, and you'll want a BIG exhaust... Defnitaely over 200 at the flywheel. I definately wouldn't expect any lower than that, but I am not sure how much more.
12:1 compression... Damn.
Is that a resonable figure?
I would look at some N/A race engines... seeing what compression they use.
With that kind of compression I would definately go with 3mm apex seals... You will be running a very high risk of detonation if you aren't running 100 octane all the time.
3mm seals can handle quite a bit of detonation- one good ping can break a 2mm, while a 3mm will take a LOT of abuse. Worth the insurance I think, though they can break, but you have to pretty much TRY to do it! They also seal better at high RPM's because of higher centrigugal force exerted outwards onto the housing by the seal.
Oh- and FD side springs- they are much better.
You need a milling machine for that though- the groves have to be perfect. Any machine shop would do it- rotary "specialty" shops charge a ridiculous amount, up to 800 bucks!!!!!!!! It is really just a very basic machine job, and should cost about 100 bucks or less, that's how I got mine done. Just another example of "specialty" overpricing.
As for HP figures, I really don't know, but with mild porting, and you'll want a BIG exhaust... Defnitaely over 200 at the flywheel. I definately wouldn't expect any lower than that, but I am not sure how much more.
11.5-12.0 CR would be safe at a conservative ignition timing, as long as the engine had adequate cooling in that area. Im looking into ways to increase the cooling efficiency around the spark plugs(big hot spot). RB and a few other places machine grooves into the metal around the spark plugs to help it cool better.
11.7 CR rotors would be good for 20-25 RWHP OVER S5 rotors in a PP motor.
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