engine questions-rebuild
01-17-2023, 04:13 PM
#1
New Member
Thread Starter
engine questions-rebuild
so ok, I have this series 1 4 intake port engine I'm rebuilding (and its a reman as indicated by tag I found.). Was this engine only in the automatics? BTW, I have several engines and have rebuilt the 13b's before, but they were FC;s and FDs..
I don't have the rx8 engine manual or electrical manual, where can I find and download those free on line?
Specific questions:
1. Is there a 'fuel return'' from the FI system, or is it a one way system? The FD had a regulator and fuel return. I'd like to see a diagram of this fuel system. The injectors seem to have only 1 supply?
2. I'd like to post the parts removed for sale, like the oil spray pump and lines and injectors, and misc other parts. Is this ok?
3. Who sells custom parts for these Renesis engines-like an intake port, block off plates, etc?
I'm sure I;ll have more later as I strip down this engine.
I don't have the rx8 engine manual or electrical manual, where can I find and download those free on line?
Specific questions:
1. Is there a 'fuel return'' from the FI system, or is it a one way system? The FD had a regulator and fuel return. I'd like to see a diagram of this fuel system. The injectors seem to have only 1 supply?
2. I'd like to post the parts removed for sale, like the oil spray pump and lines and injectors, and misc other parts. Is this ok?
3. Who sells custom parts for these Renesis engines-like an intake port, block off plates, etc?
I'm sure I;ll have more later as I strip down this engine.
01-17-2023, 07:13 PM
#2
NADM was an anemic 4-spd auto trans only and I believe the trans bolt pattern is different. Pretty sure I have an iron and can verify that for you if need be. So unless it was an import engine with manual trans this would require importing a manual trans rear iron from JP or UK. They were sold with the RX8 version of the FD 5-spd there and a few other international markets.
fuel system is dead-head style with a relief valve within the in-tank pump module that operates the siphon to pull fuel from the RH side of the saddle-bag tank over to the LH side where the pump module is.
some of the parts in the 4-port are different than the 6-port, you can sell them but just be sure to specify they’re from a 4-port, which the stat gears are weaker on the 4-port so you might want to change those.
there really aren’t many hi-po type parts for the Renesis, or at least most of them I wouldn’t recommend you throw your money at merchandisers for. Because some people are only to eager to sell you whatever you ask for even if the net result is zero or negative. The hardest part for old school rotary people is understanding that despite all the similarities, a Renesis needs to be treated as a different engine in some respects.
First and foremost is the zero-overlap port timing design. Which totally revises everything you think you know about rotary engines. Porting or adding overlap generally decreases performance and durability. In 17 years I’ve yet to see any ported etc. NA Renesis outperform the best stock port Renesis re: 6-port engines. The 4-port is a little bit of an exception in that it has slightly different port timing and from the factory makes more peak torque than a 6-port. So you can revise that to gain a bit more up top and a bit less down low. There’s nothing significant you can do for NA power though.
Zero-overlap means no exhaust pulse tuning; none. Search for my “header” thread for more info. Adding overlap doesn’t create it thanks to the shared siamese center port and some other variables that take a lot of time to explain by text. On a Renesis it’s all about the intake resonance tuning with completely repositioned intake port locations and sizing. Mess with it too much past the UIM and you’re off on a fishing expedition that’s likely to cause more harm than gain. Most critical of all is the internal sealing which defines compression and the ability to fill the intake cycle with as much air as possible. Any gaffs here cost performance, yet getting it right is not as easy as many who came and went over the past 17 years of my being on here thought.
Daryl Drummond was one of the few builders that ever figured it out, with his (stock port) blueprinted & balanced 6-port engines generally in the upper-260ish to low-270ish bhp range, generally around 8100 rpm or there abouts. The most he ever found by porting was 10 bhp, at the expensive of rotor seal life. Which is quite a gap to his 350ish PP 13B high revving race engines. He never did much with the 4-port. It just wasn’t worth messing with from a performance perspective; roughly 2/3rds output of a 6-port. Two things that kill side seals on the Renesis quickly is exceeding 8500 rpm often/excessively and EGT over 1650°F.
regards.
.
fuel system is dead-head style with a relief valve within the in-tank pump module that operates the siphon to pull fuel from the RH side of the saddle-bag tank over to the LH side where the pump module is.
some of the parts in the 4-port are different than the 6-port, you can sell them but just be sure to specify they’re from a 4-port, which the stat gears are weaker on the 4-port so you might want to change those.
there really aren’t many hi-po type parts for the Renesis, or at least most of them I wouldn’t recommend you throw your money at merchandisers for. Because some people are only to eager to sell you whatever you ask for even if the net result is zero or negative. The hardest part for old school rotary people is understanding that despite all the similarities, a Renesis needs to be treated as a different engine in some respects.
First and foremost is the zero-overlap port timing design. Which totally revises everything you think you know about rotary engines. Porting or adding overlap generally decreases performance and durability. In 17 years I’ve yet to see any ported etc. NA Renesis outperform the best stock port Renesis re: 6-port engines. The 4-port is a little bit of an exception in that it has slightly different port timing and from the factory makes more peak torque than a 6-port. So you can revise that to gain a bit more up top and a bit less down low. There’s nothing significant you can do for NA power though.
Zero-overlap means no exhaust pulse tuning; none. Search for my “header” thread for more info. Adding overlap doesn’t create it thanks to the shared siamese center port and some other variables that take a lot of time to explain by text. On a Renesis it’s all about the intake resonance tuning with completely repositioned intake port locations and sizing. Mess with it too much past the UIM and you’re off on a fishing expedition that’s likely to cause more harm than gain. Most critical of all is the internal sealing which defines compression and the ability to fill the intake cycle with as much air as possible. Any gaffs here cost performance, yet getting it right is not as easy as many who came and went over the past 17 years of my being on here thought.
Daryl Drummond was one of the few builders that ever figured it out, with his (stock port) blueprinted & balanced 6-port engines generally in the upper-260ish to low-270ish bhp range, generally around 8100 rpm or there abouts. The most he ever found by porting was 10 bhp, at the expensive of rotor seal life. Which is quite a gap to his 350ish PP 13B high revving race engines. He never did much with the 4-port. It just wasn’t worth messing with from a performance perspective; roughly 2/3rds output of a 6-port. Two things that kill side seals on the Renesis quickly is exceeding 8500 rpm often/excessively and EGT over 1650°F.
regards.
.
Last edited by TeamRX8; 01-17-2023 at 07:19 PM.
01-17-2023, 07:28 PM
#3
Star (Formula Pro) Mazda Renesis tutorial, some of it is only relevant for the race car/ecu setup
http://www.rx8help.com/uploads/7/3/4.../starmazda.pdf
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http://www.rx8help.com/uploads/7/3/4.../starmazda.pdf
.
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