4AGE crank/rods

[merc-blue]

Im currently looking at options in regards 4AGE cranks.

While most poeple go a late crank with 42mm rod bearings for both the larger rod and 20mm gudgeon, when building a engine, im looking at going the otherway.

Im not looking at big revs or extreme power in the 170HP range,
I have established my head being a small port with individual throttles, moderate porting and problly 1mm OS valves (becasue I can) and cams in the 280 degree range
Block im undecided as im yet to weigh a 3 rib vs 7 rib, but will likely play it safe and go a 7rib.

Crank, rods and pistons im totaly undecided,
while i feel OEM (late) crank rods and pistons will do the job with just a clean up.
The curious side of me wants to take weight out of the crank and rods.


So my questions to the community really are.
Has anyone had success with early cranks/rods?
Has anyone lightened either a early or late crank and been successful?
Has anyone weighed early and late cranks and rods?
Has anyone ever broken any OEM cranks or rods? under what conditions?

[slow laser]

search.

http://www.toymods.net/forums/showthread.php?t=13990

30psi 4agte is running more power than most on stock rods and pistons.



as for early model cranks and such, as long as it was balanced and prep'd properly i dont think there would be any problem with them... they are strong for a N/A motor to say the least. Just use good bearings, and the right clearances, maybe shim the oil pump a touch, radius the oil return and anything to help the oil supply.... worked for the 1G i built and they are horrid in the bottom end (oiling)

[merc-blue]

no shit. nor does your post have anything usefull in it.
.

Maybe you should have read the initial post

[Dimitri]

ive heard of early cranks breaking, but its only on really mistreated engines that this every happens.

the main thing holding back the early crank/rod set up, is the lower CR. of the piston.

obviously there are tricks to make it back up.. but it doesnt really make sense too. i would be of the opinion that if youre gonna run "280" cam, youll want as much cr as you can get.

either crank can be lightened significantly, but will obviously need to be well balanced afterwards. and seeing as they come from the factory fairly well balanced, again it becomes a cost v's gains debate.

pretty much i think it comes down to the early bottom end only makes sense if youre doing a standard rebuild/maybe some very small cams and plan to keep the factory ecu and want near factory driveability.

[slow laser]

Maybe you should have read the initial post

IF close to 300rwkw can be handled from the standard GZE rods and crank (same as late model) than how is there going to be any problem with your 170hp on early model internals... as i said before, build it up properly and there shouldnt be a problem at that level, just keep the oil supply up.


i read ur first post, and the minimal differance in late and early model crank/rod combo isnt enough to have dramas at 170hp imo. Use good bearings, extra oil clearance and keep the oil to them and dont let it ping. simple.

[fixeruperer]

ae92gze rods are too heavy for a n/a rod, a 20v (complete engine) would be better for n/a and they have tiny light rods anyway.
170hp @ wheels is a fair stretch for the 1.6, what comp were you thinking of running ?

[slow laser]

no one said anything about using gze rods

he also didnt say hp was at the wheels or motor if the 20v's make 150-160 stock, then the early model bottom end should suffice ?

[merc-blue]

Dimitri high compression forged pistons for 18mm gudgeon are easily available from places like SPS who made the group A pistons for 4AGEs, not cheap but a good piston.



20Vs didnt make 150 BHP stock that was a case of bent truth from toyotas marketing.
plus getting them to 170-180 HP isnt easy becasue of the over complicated inlet and combustion chamber... hence 20Vs arent good engines

Have you seen a early 16V rod next to a GZE rod. there is no comparison the GZE rod is about twice the thinkness.
How can any of the information related to the GZE realate to the early bottom end.

I didnt ask for the opinion of people with no proof. i wanted experiences and evidence


Comp would be in the 10.5-11: 1 range.

Most of the engines i build have limitless budgets and therefor i would just get a hollow journal crank made, rods and pistons. but alas thats not the money i have to spend on my own engine.

[Dimitri]

im aware of the pistons availability. wiseco do one too.. less than $700 u.s...

but if youre only shooting for 10.5:1 to 11:1 cr.

genuine ae92 pistons are $400, and 20v short motors sell for $300, and less sometimes. $100 .5mm hg, and youre there.

it just doesnt add up to me, spending money on a clearly inferior motor. still a great engine, but when you sit it next to the later versions, it just doesnt make sense to spend alot of time on machining ect, when a short motor can be had so cheaply.

also, if machining is free for you, you should look into honda pistons.. b16 pistons look viable... did some x referencing, they have a slightly lower compression height, but a larger dome volume. if you can get the little end re- bushed to 21mm, and deck the block about 1mm, youre gonna end up with an easy 11:1, with just a standard hg.

chatted with the guys at JHH about it and it looks viable.. for me it was still adding up to a bit too much cash to justify that route over just getting some wisecos.. but for you maybe it could be a winner.

[Hiro]

ae92gze rods are too heavy for a n/a rod, a 20v (complete engine) would be better for n/a and they have tiny light rods anyway.
170hp @ wheels is a fair stretch for the 1.6, what comp were you thinking of running ?

From recollection, AE92 GZE rods are same as smallport rods, and silvertop 20v rods are same as AE101 GZE rods. The twigs you are referring to are blacktop 20v rods.

In short, the GZE shares the same bottom end, + low compression pistons, as the equivalent N/A 4AGE of the time.

And according to Bill Sherwood's site, the 40mm crank weighs 11kg, the 42mm crank 11.7kg. So not too much difference there (about 6%)

[feral4mr2]

merc, have a chat with bill strong on the mr2oc.

[merc-blue]

Dimitri, the only reason i would go a cast piston over a forged piston is for weight savings as forgies are generaly heavier, if i go cast OEM small port are the go may need some work on flycuts. decking the block is by far the easiest and cheapest way to get compression, although not ideal.
You mention the 20V i really dont like them there port and Combustion chamber design is overly complex.
and i wouldnt even consider putting a engine into my car that i haddnt atleast done rings and bearings on.

The early Rods 18mm gudgeon are quite abit smaller than any of the later rods (more blacktop sized)


Feral i will do.

[Dimitri]

short motor = bottom end the 20v st heads are a bit shit i agree but i wasnt suggesting using one. by far youve made the best choice of head for an NA 4A engine.

what im trying to get at, is that it seems like youre planning on investing money (spending up on pistons, time if not money machining) on a bottom end, no one can seem to definitively tell you is going to hold up, v's one many people can tell you first hand, is happy to live at 9000 rpm with only a few fasteners upgraded, and a good balance job. for a saving of $300 or so.

my suggestion of the ST bottom end w/ae92 pistons was just one that might give you similar performance as your early bottom end with forgies, but with greater potential down the track, and costing the same money.

the crank and the rods arent the only considerations either. the later block is sturdier, not just with the extra ribbing, but around the mains ect. obviously, like the update from big port to small port, its an improvement, for a reason.

check out "oldskewltoy""s (sp) thread on club4ag (he's a member here too) for detailed pics of the differences.

i dont see why youd need work on the fly cuts either, if youre only aiming for 170hp or less youre not gonna need any more lift that 8mm. which doesnt create an interference engine. maybe if you want more response, youd run alot of lift at relatively "shorter" duration, but again, if youre gonna build something more serious like that, basing it on a later bottom end seems more logical.

horses for courses i guess, if youre gonna get alot of satisfaction, from building something good from a lesser motor then go for it. but usually thats tied in with doing it cheaper.. and the price difference isnt gonna be much/possibly anything.

[DeftAnesthetik]

And according to Bill Sherwood's site, the 40mm crank weighs 11kg, the 42mm crank 11.7kg. So not too much difference there (about 6%)

Losing almost a full KG on the internals (and thats just counting the crank) makes a HUGE difference. I run 3rib NA with smaller internals, lightweight flywheel, etc., etc. Rev's extremely easily(and loses revs just as easy). If you plan on throwing the gearshift around alot i would definately recommend lightening as much in the engine as possible.

I cannot remember the exact ratio but losing weight in the engine compares to losing body weight at like 1:50.

[Billzilla]

The small crank & rods will be fine - the 185hp odd engine I built a few years back had that in it by my choice as I wanted a lighter crank (And I took another ~0.7kg off it was well) and the smaller diameter bearings as they give a little less frictional losses.
I ran it to 8600rpm no probs and the guy I sold it to in 2003 has done the same since then.