Ok, this year I want to build an engine for FI. 10-12 lb boost only. 325-350 rwhp range.
My question is what is done differently for the internals? This is NOT a discussion about injectors, tuning etc etc., OK?
Are the internals handled any different for FI than for NA? Things such as clearances, oil passageways?
I do hear its good to go with a deeper apex seal from an earlier model, but what about the side of the rotor?
Yes we can speak of swapping rotors too--lower compression set up. There is a thread about that so we dont have to repeat a lot of things already mentioned.
For this power level I dont think it is necessary to dowel pin/stud the engine?
Anyone waffling the coolant passageways yet?
Looking to increase life expectancy--40-50K street miles with occasional track.

 

clearance is the most important thing, Stock/factory engines have mad loose clearance. they use pre-cut seals at factory.

at 10-12 lbs of boost i dont think u need to use deeper seals (not even 3mm seals)

generally speaking no point of swapping it to lower compression rotors since u need more boost to get the hp back, and more boost usually means higher chance of f-ups.

walfing? u mean to make the fins right? hmm, i don't think you need that either, not for the amount of boost you aiming at, but if the engine is apart it doesn't hurt to grind them I guess.

what im thinking is that you can try to use 1 pc ceramic apex. a bit harder for start up but they seal real good. and its very very easy on the rotor housing which makes your engine last longer.

oh Balance the engine with flywheel and pressure plate helps too.

 

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Yep i have been thinking about the balancing. Especially with aftermarket flywheel. Even with the correct weight the engine just feels different than with the oem flywheel etc.

 

stock flywheel is heavy for a reason

if you plan on doing lots of high rpm of course u should balance it, oh almost forgot u also need to do some rotor face clearance.

hmm, it sounds like you might as well just get RB's Light weight rotor, it has most of the things you are looking for, but its not the weight thats most important, its the snap-ring.

throw some Ceramic apex, set to side seal clearance to hmm was it 0.0015 ? then you are good, at least that's what Im planning to do for my FC. lol

oh one more thing I just remember, I read something that the Renesis's E-shaft is NOT heat treated, this is also why its a lot cheaper than the older e-shaft. not sure if its true. Mazda might think Renesis will never get as much stress as the older engine or its just a cost cutting effort ? who knows.

You also can cyro-treat the gears for stronger/higher reliability.

 

WOW quoted for posterity

 

well best I can come up with is that there is not much difference in na/versus low boost builds(non high rpm).
Just use new housings, the deeper groved apex seals, clearance the sides better, balance the assembly, work around the coolant passages at the sparkplugs and thats about it?

 

aftermarket apex apex seals and street porting I think will do the job. For 325whp even stock motor may be sufficient.





well the text below is chosen from pettit racing recommendations

street port is the right choice for forced induction Renesis setups. modifications improve efficiency and flow with out major changes in port timing, benefits include more power delivered through all the rpm ranges as well as better fuel economy and improved longevity. Special machining to improve coolant flow around the exhaust ports and reduce surface protrusion around the leading spark plugs, these modifications are a must do for turbocharged Renesis Engines.

 

Careful with those deeper apex seal slots.

 

this is not a bad thread at all, i understand what the issue is. i wanted to have mycar be safe as possible and wanted it to be built so i could push 500hp and by taking care of the main faults and issues that are brung up about. but over all making it more reliable than a stock motor would be.

 

I hear you Ray. Our rotors dont leave a lot of material to work with.

Cam does recommend the exhaust port work--i had forgotten about that. Cam doesnt even like header wrap due to the fact that it helps to keep heat in that area.

I do think that hp level is what most folks will go for? I know its enough for me.

Juan just got an engine with Cam's FI port. He is breaking it in. Then has to go to fine tune it etc.
Ok I think I have it:
1-- new or excellant used housings?
2- deeper apex seals
3- water jacket work around plugs and exhaust ports
4- proper side seal clearances
5- enlarged return oil passageways?
6- balance the assembly with your own flywheel/counter weight?
Once again--for low boost (under 12) , normal rpms (redline 8.2K), with whp level at 325 or so?
Good receipe?

 

1. I would say just get brand new housing
2. I dont see the point. Not for your target hp level
3. You can do that.
4. Applies for all custom build engines.
5. I dont see the point.
6. Of course.

But again od, u should really consider rb's light weight rotor and ceramic apex.

 

Why?

 

Some good suggestions here . Couple of points I'd add

*My stock depth "unbreakable" Esmeril seals seem to be holding out well - 17000 miles so far . But the Idea of a 1 piece also appeals .
*Whatever the cheapest way is to strengthen the dowell lands is well worth the insurance . Studs or dowells - not sure what is best . Also have an idea for a very cheap improvement to the very weak front dowell land but it is as yet untested.
*Would not be too concerned about side seal clearancing - we are not looking for optimum sealing . Just getting the job done and lasting .

 

Dowel at this power level? You really think that would be a thing to do? i mean I havent much about that unless you are pushing for more power?
The bendy apex's are interesting--i have to agree.
side seal clearance is always a good thing to do? I havent heard much conversation about blow by with FI to the oil pan area (sides can have an impact on that too) but I think we are getting more than some may think? which in the long run may affect things?
OD

 

cuz he wants best of the best.

ceramics are very very easy on the housing = longer housing life.

plus ceamics use stronger springs which seals better = more stable power.

rb light weight rotor is not the important part, the snap ring is, so the parts will stay in place at all time and not striking all over the place (high rpm)

it sounds expensive but if you count parts by parts, its not that much really. they just charge u couple hundred bux for the labor, with the light weight and balancing. Balancing alone sometimes cost 2-300 bux already.

 

Don't have the irons ported but have them worked on. Dave at KDR (speedsource) was showing me where he sees the FI take a toll on the irons. Worth looking into.

 

Nothing.
Just do it right for NA and here are no differences for FI.

 

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So ........ of all the 8 (?) engine failures you have had , you don't think you could have done anything to the internals that would have saved any of them ?

 

Nope.
None of the failures were initiated by anything inside of the motor. Not a one.
The detonation failures (2) were tuning (motor #1) and a wastegate line failure (motor #2). Nothing inside of the motor - not even unobtanium apex seals would have made any difference.
The bearing failures (motors #6 & #7) were just from using junk (and not paying attention).
Two of the other failures were cooling-related, which is all accessory parts.
One motor had an unidentified object go through it.

All of the things that have improved in the builds are techniques, not re-engineering or non-OE parts and are part of a proper NA build.
Mainly, use of a good sealant and hand-clearancing the side seals very tight.

 

I'm not an expert on where the Renesis is weaker than past rotaries, but obviously past rotaries were able to endure extreme increases in factory power levels with no internal part changes (eg. S4-S5 n/a, how many stock engines can take 4x increases in power?). I thought most of the Renesis parts (seals aside) were suppose to be stronger, not weaker than in past engines (?).

But wouldn't the higher RPMs combined with power levels much higher than non-FD rotaries suggest it would be designed to be strong? Has anyone actually sheared a Renesis e-shaft?

 

Mazda did a few things "wrong" with the 13B-MSP (Renesis) or should I say they "thought" it would be ok, but in the end it failed ? no one knows for sure.

no stock engines can go 4x increase in power while getting the same kind of engine life span as stock engine at stock power levels.

if I want power I wouldn't get S4, turbo or NA,

Even with S5 you still need to do a few things before you can get any serious power from it. and those always come with a cost (engine life, mpg, idle)

a J-Port S5 NA can go into the 300 hp ~ range. but idle its gonna suck (at least 1.2K rpm), mpg gonna suck, engine life gonna suck, and its gonna be loud as F (cops will want to talk to you every 2 blocks)

Thats what I read. No way for me to verify, take it as gain of salt.

I haven't seen a snapped in 1/2 MSP shaft YET, but I heave seen S5 and S6 (FD) e-shaft snap in 1/2. usually breaks off at the rear housing. and none of them were running at stock power level.

 

You might have a point about the ceramics but everything else is of no concern in a properly built and tuned boosted engine.

 

I have heard of one that twisted at about 500 h.p.

 

No one said stock lifespan. There are ~600hp cars with stock S4 n/a blocks. I'm not counting ports as an internal engine modification as the point I'm trying to make relates to the strength of the parts (although I suspect you could probably do it with stock n/a ports while negatively affecting power band). I've been in one such car that's done ~15-20,000kms so far... on internals that had done ~240,000km previously.

What do you consider serious power? It's not a stretch to suggest that you can do 350-400hp reliably on a S4/S5 without any changes to the core engine. Seals aside, I don't see why the Renesis would be any worse as it has some advantages.