Jeff20B

iTrader: (13)

I'm gonna use whatever I've learned over the years to build a high powered R5 for the brown car. I'd like to double its stock GSL-SE HP rating from 135 to 270 and do it reliably on old school parts.

Details and pics to come as I work. For now, enjoy a picture of an R5 rear iron I intend to use.

74 ported and smoothed casting flash in the runner.

Jeff20B

iTrader: (13)

You came in here looking for big HP and were dissapointed at only a goal 270, right? Now you're thinking you won't read further as there's nothing to learn here. Well friend, first let's consider the stock R5 engines were rated at 100HP (or 110 for the 13B). Next let's consider these early irons are only really capable of up to 300HP or maybe more (Y irons will split at 300 aparently, thus I'm going with R5). Then let's remember the FD only did 255HP stock. So if I can make 270 with an overhead safety cushion of 300+, that's tripple the stock output of a common R5 engine back in the day, still double what the flagship GSL-SE could do, and still more than the stock US-spec FD. I'm sure that's nothing to feel inadequate about.

If you'd like to add your two cents about R5 castings vs Y in power handling capacity, please do.

woodmv

iTrader: (8)

Hell, I'd just like to learn what the differences in the R5 and Y castings are, and I'd be interested to see the surfaces of the irons where the big water seal O-rings seat so if you have pics please post! I've torn apart three engines and have a mix-match of R5 and Y irons and I'm not sure any of them are useable.

I'm gonna watch this thread closesly to see how you do - I'd LOVE to have that much HP for my 79! Go Jeff GO!

j9fd3s

iTrader: (3)

turbo? there is a LOT more iron in an R5 or Y casting than the FC/FD stuff, i'd think 300hp isn't a problem...

Indio21

I'm in the same process, slowly but surely I will make it, I have a total of 4 engines and one set of 6 port irons to play with, that being said here comes my question and please feel free to laugh, how can I tell the difference between this irons and how much difference does the amount of main bolts play in this set up?

Jeff20B

iTrader: (13)

I don't know if I can answer all of your queastions adequately here, but I have covered the differences in the past.

Basically yes I'll use a small Aaron Cake style turbo and the engine will have 17 or 18 tension bolts (18 is better than 17 but it depends on the casting). Still debating hardened stationary gears and a street strip pressure plate.

Another option is a GT35 but I'm not there yet, neither is the car (from a power handling perspective).

mustanghammer

iTrader: (3)

Watching this because I will starting the engine build for my STU project shortly

Shredduuhh

iTrader: (11)

im curious as to what intake your going to run.... your hp goal will easily be achievable... no worries Jeff

DreamInRotary

iTrader: (49)

Should be a fun project, good luck and more power - twice the usual amount- to you!

Jeff20B

iTrader: (13)

Thanks everyone! Hmm, maybe I'm going about this idea all wrong. I like what j9fd3s is saying about how there is more iron in the early "irons" but the thing is it's located more intelligently in the later irons, thus making them lighter and stronger. However I know the S4 irons tend to break pretty easily so most go for S5 or S6 stuff.

My strong R5 iron has what looks like an S5 rib at the oil pedestal and also 18 tension bolts so I figured it could handle 300HP or so.

I wonder if I could get away with just a Y plate at the power levels I'm looking for? They say the S4 irons will break at 400. Well, the Y irons have more iron in them and lack a rib at the pedestal like the S4 irons. Does this mean an R5 with a pedestal rib is capable of over 400HP? I don't really want to push it to find out. I'll let someone else do that.

For that matter, what about the old school rotors? They have 3mm apex seals which some say are better for boost, while others say 2mm or 3mm; doesn't matter when they shatter.

Also the old school rotors have less roll pins holding the rotor gear to the "basic rotor" as RB calls it. Do I need the extra roll pins that all S4 and later rotors come with? Should I look for S4, S5 or S6 rotors? If I'm not looking for high RPMs, will I need to worry about it?

Do I need hardened stationary gears for 300HP? Do the heavy old school rotors demand hardened gears? Is it a high RPM thing or a high power (boost) thing?

Wow, looks like I'm asking more questions than I thought I would.

joeylyrech

iTrader: (11)

If turbo and you only want 300 or 400 hp run 2mm FD rotors,FDs do come with the rotors bearing set crews and multi holes bearing,fd oil pressure regulators and off course use the fd stat gears 2.If you want more hp get S4 turbo rotors with multi window bearings and set screws,S4 rotors have a thicker better casting and can handle more power than later s5,s6 stuff.

If non turbo run S5 NA rotors with hardened gears and multi window bearings,also run the oil pressure regulators.

Jeff20B

iTrader: (13)

Wow, thanks for the info! I actually have an FD shortblock. Maybe I should abandon the high HP R5 concept and move over to the FD? I already bought a J.W. intake manifold and have an RB Holley for NA break-in. Then I have access to a GT35 turbo and a full 3" exhaust, should I choose this route. I also have a boost prepped Holley 650 double pumper that needs a rebuild kit (never rebuilt a Holley before).

On a related note:
Last year I stacked an FD engine with some S4 T2 rotors for PercentSevenC. He was looking to make 400HP. Sounds like the S4 T2 rotors were a good choice. He has a MegaSquirt and wants to swap to a walbro 255.

bad 83

iTrader: (3)

Just going to chime in on this one. I am running a large street port with S4 NA 9.4 rotors, RA Super Seals, Viton coolant seals, S4 TII irons, S6 housings, S5 TII lower intake, S6 upper intake and throttle body, T04E turbo, 550 primary and 720 secondary injectors, R-TEK 1.7, and I dynoed 330 RWHP and 300 RWFTLBS. As far as clutch and trans, XTD 6 puck clutch and race pressure plate, S5 J-spec TII trans.

I opted for the higher compression rotors because I also wanted the low end torque. When I dynoed my car I had the rev limiter set at 7200 rpms. I told the dyno driver to WOT my car at 2K rpms in 4th gear because my turbo would full spool by 3500. I also had the boost controller set at 15psi.

Right now I am in the process of installing a FD divided tubular exhaust manifold and a GT35R divided anti-surge ball bearing turbo with a .63 AR hot side. I LOVE the smaller hot side turbos. They will hit full spool at such a lower rpm.

Hope my setup info sheds some insight on how you want to proceed.

Jeff20B

iTrader: (13)

Wow thanks for the awesome info! Two of my R5 builds received S4 NA rotors. The REPU and the brown car (GSL-SE). I did the REPU's engien this way obviously for more low end torque. Then I built a spare for it and decided to throw it into the SE for break in. It turned out so nice I decided to keep it there! lol But it really does belong to the REPU. Hence the reason for this thread to see about building a high powered R5 with the really thick irons and how it would compare with the FD shortblock (and whether I should build it instead).

You'd be the person to ask this question. Back when you had a blow through Nikki, I'm sure it had its share of problems as all blow through carbs do. Would you say the tuneable EFI is the far better choice here? My FD shortblock could have EFI if I had full intake manifolding, but I don't. I do however have a J.W. manifold for a Holley and a boost prepped Holley just sitting.

Anyway if the Nikki is a good choice to get my feet wet in the ocean of boosted rotaries, I'll do that first on the current R5 in the GSL-SE. I guess I need some direction. I don't know how to proceed.

j9fd3s

iTrader: (3)

don't forget in the old days, the P port engines were making more than 300hp NA, and the irons were fine...

this is an arbitrary number, a few years ago we took a survey, and broken dowel pin follows ECU choice more than it does HP, ignition accuracy is a big deal, and some of the older cheaper ecu's just aren't good enough. for instance the power FC guys need to be making huge power to break a dowel pin, while an E6K can break the dowel cruising down the freeway.

the 3mm seals don't seal as well as the 2mm, but the rotor is plenty strong enough. the roll pins, and weight of the 12lb 13B rotor mean that you should keep the revs down (7500?), but 7500 should be more than enough.

S4 rotors might be a good upgrade, my preference is the turbo rotors, low compression means you get to run more boost and more boost = more power.

IMO its an RPM thing, again, the stat gears seem totally fine to go 7500+ rpm, using the lighter rotors gives you more margin.

actually the basic engine is ok for 300hp, but all the little upgrades do improve your reliability though

ioTus

iTrader: (5)

NICE build bad83 - i like the high compression rotors and small hot-side particularly.

Jeff I haven't dove into the tuning process of the EFI yet, but i remember how much of a PITA tuning the carb was for me. But then I dont know carbs - someone who knows what they're doing would have had the blowthrough running a champ LONG before I did. Setup was a Weber 45 and S4 turbo / block with ported wastegate.

Jeff20B

iTrader: (13)

ioTus, I remember that car. The next owner, Codeblue, raced my friend's orange FB with a Camden 5" and they were equal on the freeway. Both had problems. The Edelbrock in the orange car kept surging which I believe was caused by the donkey door not having quite enough air to keep it open (air filter issue probably). The other car kept having a charge pipe pop off but I don't know whether it did that during their run or not.

Your old car also used to blow huge flames under decel. Kinda cool to see, but we know it's just wasted fuel. I'm hoping the Nikki won't do that. Your car also presumably had a locked Dizzy. PercentSevenC also had a locked dizzy and a boosted DCOE. It too had problems which I won't get into. I'm hoping my setup won't have those problems.

I have a semi-locked dizzy which appears to only advance to 10 degrees (found it that way amoung of a bunch of parts). I'll test run it on an NA to observe the timing marks before I use it. But if it really is able to only advance to 10 degrees, that should be perfect. It will idle at 0 TDC and then only advance to 10 degrees and stay there which should be perfect for boost. PercentSevenC seems to think this will fix several of the problems his setup had, and the Nikki will fix all the others.

Jeff20B

iTrader: (13)

j9fd3s, thanks for shedding some light on the subject. Sounds like I could use the current R5 engine with S4 rotors in the brown car and make 300HP. I just need a good intercooler and a good tune.

ioTus

iTrader: (5)

Mine had a locked dizzy, correct. I think we were at 12 deg advance, but its been quite a while (8 years now wow). Excellent insights.

I had fantastic experience with the Isuzu NPR intercooler. I think the small one.

bad 83

iTrader: (3)

The Nikki isn't going to be good enough for anything besides a stockport. Your best bet is going to be a Mikuni 45 with 40 chokes.

Jeff20B

iTrader: (13)

So in a way you're saying a big Nikki might work? I have a "big" Nikki. The venturis were hogged out to 26mm and 30-something. It's one of those old school racing carbs at like 465cfm or so. It's practically already boost prepped as it is. I've since done the Sterling accel pump mod so it flows while the secondaries open. I'd love to use this carb for boost on a 74 ported 13B.

Jeff20B

iTrader: (13)

This is what I was talking about. See how "big" this Nikki is? Should be big enough for a 74 ported 13B and boost.


Just for comparison, here is a typical stripped stock Nikki. I see what you were saying. See how "small" it is?

bad 83

iTrader: (3)

The Nikki that I personally used was from the SAs. They were larger ports than the FBs. I used larger secondary jets, boost prepped, mechanical secondary's, and rocked on. If you want specifics of my 12A blow through setup. PM me and I'll fill you in.