How high can a 16 V engine be revved?

[racermr2]

I'd like to know or get recommedations on the max RPMs for a 16v built to the hilt bottom end? I'd also like to know what valve train and cam specs would be recomended with stock valves. I'd like to get 9500-9800 in a club racer with good reliability(4-5 races without the valve springs being used up)? I believe the "gurus from down under" have tried this or know from experience. Any recoomendations would be appreciated. Thx. in advance

[oldeskewltoy]

we are talking about a 4AGE???


They have been known to twist upwards of 14,000 rpm... requiring dry sump and block modifications.

Is 9500+ required? In my opinion... the 4AGE goes from $$$$ to $$$$$$$$$$$$$$ right about where you want to twist it too.

Keeping your desire for 5 races - 9500 to 10,000 is just beyond what I'd say you can get away with for wet sump, 9000 on the other hand is within the wet sumps capability.

dry sump for apps @ or above 10k rpm

A stock(42mm rod journal) crank, and rods can survive in a 9000+ rpm 4AGE as long as you have it well balanced, shotpeened(or other hardening process) and are using ARP fasteners. Pistons you will need custom.

TRD, or similar crank, plus H beam rods for apps @ or above 10,000 rpm

9000 rpm valve train... I'd recommend using TRD, or TODA single springs, and look @ cams with about 250 degrees duration MEASURED too .050" lift.

9500+ rpm might require dual springs - and the extra cost associated with installing dual springs.

Fully ported head REQUIRED

[racermr2]

Oldeskewltoy: Once again your knowledge comes to the rescue. I must admit that my desires for my proposed engine are obviously overly optimistic. I'm exploring what can be done to achieve the HP & RPM to run with the Hondas and Miatas. My intent is to build this engine using a stock large journal crank forging(required by the rules), 11.0 compression, after market pistons(Wiseco), stock valves(rule requirement as to size but no titanium), valve springs are free, no JDM engines or parts, no porting further in than 1 inch from manifold face, valve angles are free, and no dry sump allowed, stock intake and throttle body. Further, I realize that engine cooling will be a problem for a MK1 MR2 because of radiator placement in the stock location and no ability to vent outgoing air thru the front bulkhead and hood. However, based on the foregoing, any thoughts or recomendations would be greatly appreciated from you or any forum member.

[scottreichstein]

why dont u just use a 2zzge? revs to 9000rpm from factory?

[xero]

pretty much everything OST said, but you will NEED 12:1 to make decent power.

my 16v engine spins to 9500rpm, but stops making power at 9000rpm.
engine specs below:
smallport 16v engine
oversized valves
dual valve springs
shim under bucket conversion
304in/296ex 11in10.5ex mm cams (advertised duration)
cam gears
lots of port work
ported ITBs adapter
blacktop ITBs
custom headers 1 3/4" diameter
2.5" exhaust system
individual coil packs
82mm wiseco 12:1 pistons
treated smallport rods (couldnt get aftermarket rods for reasonable price 6 years ago)
fully balance 42mm crank
using factory smallport oil pump.

makes 119rwkw/170rwhp @ 9000rpm


the cams could easily run to 10000+rpm but the engine would be an unknown factor above 9500rpm. while the grp A cars used the stock bigport intake and TB it can be a restriction. you will need to factor this in.
you'd almost be better off keeping the engine under 8500rpm and using a smaller cam (say 288deg) so instead of having massive RPMs you have much better spread of power.

building an angry N/A is not for the faint hearted or the shallow of pocket.

[maj]

By no ability to vent air through the hood, are you talking about class restrictions on modifications, or just unable to in an AW11 MR2?

If it's the latter, I highly recommend looking at knightrous's 20v AW11. He's done exactly that for venting air and he's done it in a basic but very effective way that isn't hard to replicate.

Also, with over 12L of liquid running through the cooling system, it's very hard to get an AW11 to overheat under normal operations. I know because mine overheated haha.
If you are sticking with a mechanical water pump, the more RPM you are running, the better your coolant will be flowing as well!
You can also swap out the stock radiator for a dual row aluminum one for more effectiveness. Some SPAL fans could surely better the stock thermofans too.

For higher RPM you should look at ensuring the oil flow is maintained on a stock 16v, and since dry sump is out of the question, adding an extra baffle into the stock sump is an absolute must for an east/west engine like in the AW11:
4AG Oil Pan Baffle Kit, Twos R Us

[xero]

If you are sticking with a mechanical water pump, the more RPM you are running, the better your coolant will be flowing as well!
You can also swap out the stock radiator for a dual row aluminum one for more effectiveness. Some SPAL fans could surely better the stock thermofans too.

err, no.
the higher the RPMs the greater the chance of churning the water and DECREASING flow. which is why a larger water pump pulley to reduce the speed the pumps turns at is a good idea as it will actually move the water around the cooling system instead of it frothing up in the pump and doing 4/5ths of fuck all.

[maj]

I'll concede that one, but the rest of my cooling advice around the AW11 still stands.

[trdee]

Factory water cooling system will be MORE than capable racemr2. I have seen 12000rpm done on the standard crank, but for longevity I would consider 9500rpm to be the upper limit as per xero and OST's suggestions. Also, if you can get a drysump system happening, do it, as the stock oil pump probably wont like constant abuse at those rpms for very long.

[HJ60]

As already suggested 9000 RPM would be an easier goal originally.

For Valve train i can highly recommend the Toda Valve Springs =) - They are rated to 9000 RPM from memory?

I'd have a look at the MRP (Sponsor on here) and his Dry Sump Kit!

MRP LTD - Manon Racing Products

[dnegative]

Oil pumps dont really seem to like sustained >8500rpm from all accounts, Toda and TRD (used to) make gears though so its a cheap fix
Cooking a AW11 is a pretty hard task, its got a lot of water in the system and the factory radiator will strip more than enough heat. Fit a thicker SW20 alloy radiator and leave it at that, cutting a scoop for the air is not needed nor is the unknown aero effects.

[oldcorollas]

is there any point spinning to 9K+rpm with stock valves, no porting (except for 1" of match porting), stock manifold and stock throttle?
at what airflow do stock valves and ports start choking? no point spinning faster when VE is dropping...

[dnegative]

Yes and no;

With big cams on a high comp bottom end you will make quite a bit more power, but with a stock head and bigport intake manifold its going to choke. So going to 9000rpm for the sake of it on stock gear, is pointless.

[oldeskewltoy]

Oldeskewltoy: Once again your knowledge comes to the rescue. I must admit that my desires for my proposed engine are obviously overly optimistic. I'm exploring what can be done to achieve the HP & RPM to run with the Hondas and Miatas.

My intent is to build this engine using a stock large journal crank forging(required by the rules),
11.0 compression, after market pistons(Wiseco),
stock valves(rule requirement as to size but no titanium),
valve springs are free,
no porting further in than 1 inch from manifold face
valve angles are free,
stock intake and throttle body.

Hmmm, I'd really like to read the rule book about the head, and what is allowed or denied. Matching the seats and bowls might be more "rebuild", then porting... ESPECIALLY... if the stock seat is removed in favor of a ported seat that fits the bowl casting (that way you aren't changing/"porting" the casting ) BIG money for a "stock" head

compression all you want... any cam changes allowed? Also any combustion chamber work allowed??


Also the real problem with a 4AGE head is the exhaust port... the problem begins about 5/8" in and goes all the way back to the bowls(over 1 1/4" deep). The actual outlet dimension of the 4AG port face(29mm-30mm) is fine for most applications

I'm NOT a fan of any of the off the shelf aftermarket 4AG pistons... all are based on older Atlantic technology.

This is a nice aftermarket 4AG piston (spec sheet 2/3 down page) - [AEU86] EU AE86 community :: View topic - The globetrotter (summary page 8)


BEFORE you drop a nickel... do the MATH... figure out how much this is going to cost... and if it is worth it.

[worldwalker]

Sounds like you're after a B16b.