By excessive rpm!??

I managed to break my crankshaft.

I've never heard of a 4age doing this. Anyhow, A new one is already in the works. Maybe in 2 or 3 weeks I'll be back doing my thing.

So does anyone have performance parts for sale? I'm still looking for a set of rods. 20mm wrist pin style.

Thanks,

 

use 20v internals, heard they are superior to the 16v internals. not like you dont now that already.

 

uh..i think he has a 20v already, and is doing a full motor build..?

 

no he had a blue top with gixxer itb's. if your talking about a new motor then cool! i dont care too much for 20v head because 5 valves in one combustion chamber does not make it easy for bigger valves. itb's is a fav of mine though. marks the man with the plan, and large amounts of toyota know how. so ill trust what hes doing will be the end all be all of 4ag. or maybe 3sge?

 

well its a cast crank

 

VeRTigO: You shouldn't make comments if they aren't true. If it was a normal type of crank this wouldn't be so surprising. Remember the 4age is a race engine before it's a production engine.

Maybe you should stick to hondas?

Anyhow, here's a little info from Richard White:

4A-G Crank

The 4A-G crank is by all appearance a high performance piece of hardware. Unlike many production crankshafts which are nodular cast iron, the 4A-G is forged. It is a forged carbon steel, five main bearing, fully counter balanced affair. Each journal is cross drilled for 360-degree supply of oil to the connecting rod bearings, and each hole is chamfered to aid in oil delivery. An additional feature of the 4A-G crank is that each main bearing journal has rolled fillets to improve fatigue strength.



The transition between the main bearing surface and the crank counter weight and rod journal is subjected to very high torsion forces. Compressing the material around the transition, increases the strength and, therefore, the life of the crank. Other performance features include the use of a roller bearing (Toyota p/n 90363-12003) for the transmission pilot shaft (T50 Transmission only) and the use of eight 10mm fly-wheel bolts rather than the usual six that many engines of this size would normally have. This is contrary to Toyota’s illustrations in their own repair manuals typically showing six. And because there are no dowel pins to locate the flywheel position Toyota uses close fitting shoulder bolts. If the flywheel and crankshaft are fitted and torqued properly, all the stress (compression/friction) should be at the interface between the crankshaft and flywheel and the bolt’s shear strength is only needed if something in the system has failed. Rarely do you want a design that uses a fastener in a single shear plane. Bolts are at their best in tension.

Anyhow...

 

well...
what are your plans? 20v or 16v? if it were me id go 20v bottom, red top head with you gixxer set up. im not too sure but i think it would be easyer to place all 20v internals into the reg 4ag blue or red top block. seems that radiator hosing is a pain in the ass for a black or silver top swap. im prob wrong though.

 

holy piss...

 

mark if you don't do something excessive to that 4ag i'll be very dissapointed.

 

im almost positive he will even tho i dont know jack shit about toyotas, i thought he had a 20v before lol? must be someone elses engine im thinking of

anyways, best of luck to building your new engine mark