Reliable 9000rpm 4A. Am I dreaming?

[mullett]

Just been throwing ideas around in my head all day, and since I'm a hi-rpm loving person, and these are engines raced with alarming regularity, what's the formula for a strong 9000RPM 4A? Obviously it'll be different for boosted/NA. Here's my NA list, if you thing I've missed something, or listed something unneccary, feel free to say so. Haven't got a boosted list, I don't know how well the GZE gear holds up to RPM.

NA: Basic engine: 20V Blacktop, Factory rev limit 8000rpm (I think?)
Bottom end rebuild, new bearings etc.
Factory pistons balanced
Factory rods shot-peened, linished and balanced.
Factory crank shot-peened, linished and balanced.
Sump baffling?
267 cams (?)
Heavy valvesprings.
Adjustable cam gears.
Extractors.
EMS ECU.
Lightweight flywheel.

Boosted: Basic engine: 4A-GZE, MAP
Same as above, just with the heavier GZE rods and suchforth.

How's it sounding?

RM.

[oldcorollas]

it sound slike you may need to replace parts on a regular basis

by 9000rpm, you mean racing at 9000rpm? or on the streets between lights up to 9000rpm? big difference

basically, what you want is the base engine build of a formula atlantic motor (for example) with lighter pistons, lighter rods, lighter valves... 267cams? you sure they will go to 9000? perhaps 280-300 or so...

sump baffle? try dry sump.

adjustable cam gears cos that makes a 9000rpm motor you might want solids instead, so they don't vibrate apart.

seriously? go and have a look at race motors. see what they need to do to make torque at 9000rpm and see how long the motors last, and how often rebuilds are.

there is somewhere online a spec sheet for atlantic motors.... go check that out. a race motor built for 10-11,000 will last longer at 9000...

[Dimmy]

looks pretty good I've currently got a 20V ST sitting waiting to be rebuilt as well, decided i'll be going for a high-revving n/a with ~115fwkw

Probably be getting 272 cams (still thinking out that or slightly smaller angle)
HKS adjustable cam gears
BT flywheel because they're lighter
BT throttles (maybe, because i've got the ST ones already)
ported and polished head
acid dipped block
BT rods and crank (if they're easy to source)
and custom exhaust manifold

and much more, if only money wasn't a factor, but will probably start when i finish uni this year

That'd probably cost around the $6000 mark

EDIT: PM johnny on this forum, he knows a helluva lot about the 20V's. There's a starlet going around with ~125fwkw and a very nice revving motor up to 9000rpm

[myne]

The B16B Honda engine has a 77.4mm stroke and an 81mm bore. It redlines from the factory at 8600 rpm.
The 4AGE has a 77mm stroke and an 81mm bore.
The Honda F20C has an 84mm stroke and a factory redline of 9000rpm.

I hope you're catching my drift here

There are 2 significant differences between the 4A and the B16. The first is the rod:stroke ratio. The B16A rods are 1.74x longer than the stroke. The 4A rods are 1.5x longer than the stroke. Increasing the length of the rod relative to the stroke reduces lateral loading on the bores and rods(reducing the risk of poking a piston through the block).
It also reduces the peak piston acceleration resulting in lower loads on the rods/gudgeons.
The second difference is in the bearings. During the development of the B18C, Honda asked its' F1 guys for some bearings. They're a cool sounding lead lattice arrangement that apparently stays oiled very well.

I have no idea if this would make *that* significant a difference, but I've read from a good source that rods are optimum at around 1.75x the stroke. Consider a 7A bottom end and some custom rods. If you're going for custom rods, you might be able to use off-the-shelf aftermarket Honda pistons+gudgeons.
The 4A valve angle is 2* different to the B16 and the valves are smaller so clearances shouldnt be a problem.
I had a thread over here you might have renewed intrest in : http://www.toymods.net/forums/showthread.php?t=3654

Just some thoughts.

[RWDboy]

(edit)

stuff

(/edit)Yeah i'd be looking at lighter weight valves over heavier valve springs at 9000rpm and I'm no 4A expert, but shim-under buckets at least - preferably solid lifters if possible ? Considering the lift and the gradient of the camshaft that you'd need to see 9000rpm you are talking about quite a bit of force 'on the nose' of the cam lobe if you stick with standard weight valves (and add heavier springs to avoid valve bounce).

Then you've got the ole inline 4 vibration issues to deal with, at 9000rpm you'll want lighter pistons and rods than what you get from factory. You've got two options, take material away from the rods/pistons you've got (maybe go for a lighter gudgeon pin too?) or you could get a set of aftermarket forged pistons that are made from a lighter alloy and possibly better designed for that rev range (ie longer C-C for the rod and a shorter pin-crown height for the piston).

Does the 20V run a crank angle sensor/cam angle sensor ? I really doubt you will need to look too closely at ignition timing issues, but it does help at higher RPM to make sure that your sensors etc are capable of providing an accurate signal to the ECU.

I don't think a dry sump would be necessary, but you would definitely be wanting a higher flow oil pump and more capacity in the sump. Box it out maybe, and add some baffling for sure. Oil cooler would also be a good idea as you need to have good stable oil temperatures in a hi-po motor!

[30psi 4agte]

old corollas does have a point. Are we talking race duty or just a punishment up through the hills and occasional track day.

If its race duties then a dry sump must be considered.

These motors are EXTREMLY rev happy and will be quite happy to sit on 9000 provided they have decent lubrication.
The STD oil pump can become an issue at this RPM

i put up a thread a little while back asking what 4a pumps are capable of and the man himself ( billzilla ) reckons that they are ok. ( im still skeptical) My motor runs up to 9000 very often with lots of boost throught it BUT does get pulled apart often ( every 5000 or so sometimes less) this is not due to the engine being shagged but more to see how things are coping. Everthing bearing wise is always sweet!

I dont think they would cope at 9000 for extended time with a std pump though!

There are mods to be done to the oil ways in the block ( can open em up a bit) and the oil pump can be modded too chamfering the edges of the oil ways to improve flow slightly.


One thing you dont have down is ARP rod bolts !!!!!!!!!!!!!!!!!!!!!!!!! along with ARP every other bolt!!

A crank girdle is abit over kill but if you want 9000 all day then it should be considered.

IF ANYONE KNOWS OF SOMEONE WHO MAKES THESE LET ME KNOW !!!!!!!!!!!!!!
They info i have been able to find is on the bob norwood site. I would love to get one of these but cant find an email address for him. Thats even if he makes them for sale!

[oldcorollas]

the "TRD" oil pump gears are exactly the same size and flow capacity.. just a stronger material to resist splitting apart at higher rpm...

[30psi 4agte]

RWDBOY:

20vs have shim under bucket STD

[EldarO]

it sound slike you may need to replace parts on a regular basis

by 9000rpm, you mean racing at 9000rpm? or on the streets between lights up to 9000rpm? big difference

basically, what you want is the base engine build of a formula atlantic motor (for example) with lighter pistons, lighter rods, lighter valves... 267cams? you sure they will go to 9000? perhaps 280-300 or so...

sump baffle? try dry sump.

adjustable cam gears cos that makes a 9000rpm motor you might want solids instead, so they don't vibrate apart.

seriously? go and have a look at race motors. see what they need to do to make torque at 9000rpm and see how long the motors last, and how often rebuilds are.

there is somewhere online a spec sheet for atlantic motors.... go check that out. a race motor built for 10-11,000 will last longer at 9000...

he asked what it took to make a reliable 9,000 rpm motor, if this means making a motor that can handle up to 10-11k to see 9k rpm reliably, i think thats what he wants

love ya stu

Eldar.O.

[Vios-GT_07]

NA: Basic engine: 20V Blacktop, Factory rev limit 8000rpm (I think?) - some say 8100, some say 8500...

Forged hi-comp Pistons + rings, balanced
Factory rods shot-peened, linished and balanced.
Factory crank shot-peened, linished and balanced.
New bearings and seals all around
stock sump and pump with 19 Row (that's as big as it goes eh?) oil cooler
288 / 267 cams + adjustable cam gears
Titanium? valvesprings - those extra heavy duty items that take up to 10,000 rpm or so
Extractors + hi-flow cat + coiled resonator + single loop muffler
Lightweight flywheel + heavy duty clutch
EMS / Link / PowerFC / Motronic / MOTEC etc etc...

corrections made.. hehehehe... but that should give u high revs (off the top of my head from another guy who's done this to a silver top).

don't neg rep me for saying this but one dude i know had HKS pistons and rings in an old bigport 4A-GE. Block was bored and everything was balanced out, but all that was different was slightly bigger pistons. Idled at 1000 rpm, and redlined somewhere around 8500 RPM on a stock ECU... (i reckon it had a piggyback or some fuel work to supply at the high revs)... it's been 2 years, more than 50,000 kms of trashing and it's still running today. I guess it testifies the strength of the 4A-GE and my support for how bulletproof it is...

[30psi 4agte]

so are you saying that you run 9000 all the time with a stock pump????

[Vios-GT_07]

so are you saying that you run 9000 all the time with a stock pump????

well not all the time but yea it's possible if you're going to do it..

oh u mean u wanna hold 9000 rpms for extended periods? then definitely u'll need to upgrade the oil pump or change the system altogether...

sorry i thought u just want to reach that mark safely... ? i personally don't believing in holding high revs for extended periods. It's cars, not air planes.

[oldcorollas]

he asked what it took to make a reliable 9,000 rpm motor, if this means making a motor that can handle up to 10-11k to see 9k rpm reliably, i think thats what he wants

love ya stu

Eldar.O.

"Reliable" all depends on how many load cycles it has to see
same for the turbine blades i work with.. they are rated in hours for a certain load. increase load and hrs come down exponentially (or some such mathematical term.. cbf looking up the realtion now )

with a motor, as you increase rpm, the loads experienced by all parts increase by the square or cube (can't remember now ) and THAT is the problem.

a motor that can last sayy.. 10,000km at 8000rpm may only last 10km at 9000rpm.... so thats why i said if you build a race motor to handle 10-11,000, then ince you have lighter parts for less loading AND reducing the rpm, it will last a lot longer....

so Mullet.. we talking reaching 9000? or holding 9000 for long times? and power band from9000 down to? 5000? 4000? just to give some direction to the thread.

[kingmick]

ok, revs kill engines! unless you are racing there is no point in reving to 9000rpm. my 6 litre chevs can run happy at 8500rpm and there old pushrod dinosaurs, but they dont because even racing there isnt any point unless once or twice you need the extra legs somewhere on the track because of gearing to get ahead of someone,instead of getting 1500km out of an $80k chev you will be lucky to not hang a valve etc at 500km at 8500rpm. The wear rate of even the best built 4A at 9000rpm is massive compared to 7500-8000rpm. you will be changing springs at regular intervals as they will fatigue unless you keep lift at close to factory.you will be picking pieces of a standard oil pump from out of the engine if you go to 9000rpm as a regular exercise.

9000rpm specs if you have plenty of money to keep freshening up the engine and replacing pieces that break.i know many wealth people that circuit race 4a's and none of them regually go to 9000rpm because it is expensive!

block!
1. align boring the jornal tunnel
2. cylinder boring with deck plate
3. complete balancing
4. mains girdle { you can get away without it but the jornals walk around a bit without it, which adds to wear}
5. Magnafluxing & Pressure Testing
6. Arp main studs
7. good quailty i-beam rod Oliver,Pri even argo and change length.
8. very short skirt motorbike pistons and anodise the skirts{pin height to suit rod}
9. H-series bearings to float the crank{only used drysumped but the TRD oil pump will prob be up to the extra oil needs}
10. TRD oil pump
11. bigger sump with oil trap or drysump sump
12. open out oil returns

HEAD!
1. hardness test
2. cam tunnels align bore
3. port and polish
4. recut seats for bigger valves
5. quality bronze guides
6. stainless or if you can afford $300 each titanium valves{these are all i use}
7. titanium locks
8. isky or the like race springs
9. billet cams to suit rev range
10. mesh oil returns
11. Arp head studs and cam studs
12. high qualty vernier cam gears
13. metal shim gasket
14. trd buckets or let you into a secret, i use 3sg ones.
15.

BOLT ONS
1. oversized alloy pulleys and a quality balancer.

lol i could go one but thats the basics to doing a proper 4A reving motor, you could do it with factory parts but you are taking away saftey margin and durabilty. only takes one peice to break at 9000rpm and you can loose the lot.

BOOSTED dont bother as there is no point unless drag racing only. you have all the extra torque so 7500rpm is plenty.

[myne]

If Honda can do it out of the factory with a warranty, and use an alloy block, rockers instead of buckets and use a LONGER stroke, I cant see why it cant be done with a cast iron block and buckets.

Use the 7A block. The 4A crank, and some ~135mm rods and the bottom end should hold together assuming you can oil it right. Get some titanium valves, good springs, fresh new retainers and solid buckets and I cant see why it wont be fairly reliable.

Go do some research on the Honda VTEC engines. They're the only engines I know of that are in this league and have a warranty. They have to be doing something right. If they can do it, we can copy it.