High revs, High comp suggestions?

[capn]

hey all

I have gone through my turbo phase with my old rotories and wanted to get back to the high revs and no lag of my NA rotors, but instead I want to do it with the 1UZ. So I was thinking of 11.5:1 - 12:1 CR and .20 over bore/pistons and maybe a mild cam with some head work.

But I am shooting for <400bhp or maybe even 100bhp/liter. So would I be able to reuse the stock rods with upgraded bolts to handle the motor? Or would that be pushing it? I also want to reuse the stock intake manifold, but I may switch over to ITB.

But let me hear your suggestions on a High rev, High comp motor good for daily driving!

 

[Zuffen]

The stock rods will take 400hp easy.

What they won't do is take big revs AND 400hp.

Anything over 7,500rpm is pushing the limit of the stock rods.

If you look at the cost of ARP rod bolts and the cost of rods already fitted with ARP bolts the rods start to look cheap.

Given the price of quality rods it won't add much to the cost of a motor build to have the comfort of decent rods.

If you want to rev past 6,000 and make HP you'll need cams and headers plus an aftermarket management system.

 

[capn]

The stock rods will take 400hp easy.

What they won't do is take big revs AND 400hp.

Anything over 7,500rpm is pushing the limit of the stock rods.

If you look at the cost of ARP rod bolts and the cost of rods already fitted with ARP bolts the rods start to look cheap.

Given the price of quality rods it won't add much to the cost of a motor build to have the comfort of decent rods.

If you want to rev past 6,000 and make HP you'll need cams and headers plus an aftermarket management system.

Well my stock tach only goes to 8,000 so I am not taking it past that and I will most likely set my rev limit at 7,000rpm. I am aslo going with a microtech system for the EMS, and mild cams and some inconel headers are in the mix.

so your saying that I should pop for the extra $899 and buy the rods too?

 

[capn]

another question; the rods are an easy fix but the valvetrain is another story.

What can we do to sustain higher revs and not "spit a shim" or bend a valve. I have heard of some of the other toyota engines have shimless buckets, what are the sizes of the shims needed and from what engines? And what type of retainers can I use and also what type of springs can I use?

 

[Zuffen]

These engines won't spit shims and bend valves if the shims are kept to a reasonable size.

The problem most people have is they grind the cams and need to run thicker shims, due to the reduced base circle, which combined with the cam ramp allows the shim to be ejected from the bucket.

If you're really worried swap to shim under bucket. Alternatively you could run a thin shim under the bucket plus a thin one on top of the bucket in lieu of a thick shim on top.

I can't see how a 1UZ would bend a valve as the bucket can't apply sideways force on the valve stem.

 

[capn]

These engines won't spit shims and bend valves if the shims are kept to a reasonable size.

The problem most people have is they grind the cams and need to run thicker shims, due to the reduced base circle, which combined with the cam ramp allows the shim to be ejected from the bucket.

If you're really worried swap to shim under bucket. Alternatively you could run a thin shim under the bucket plus a thin one on top of the bucket in lieu of a thick shim on top.

I can't see how a 1UZ would bend a valve as the bucket can't apply sideways force on the valve stem.

The bending of the valve concern was more directed towards the spings, such as in high rpm, floating a valve and have the piston smash it.

so if I get a nice set of billets I wont really have to worry about the shims, which brings me to springs, what is a suitable upgrade?

 

[rarson]

I would think the stock intake manifold probably isn't up to the demands of that kind of engine.

Also, I would think with the stock stroke, you're looking at more of a 9000-rpm engine when all is said and done, in the N/A arena. If you're looking for an 8000-rpm peak, I think more stroke is called for.

Just my opinion.

 

[turboteener]

You need more bore. Nothing wrong with rpm, but it will cost you big money. Why do you think turbos can come out cheaper than an all out NA motor. They are much easier on the engine. A powerful NA engine will require lots of work. You will have to address the valvetrain, long block, induction and exhaust system. In order to accomplish what you are wanting it will take money.

One thing to keep in mind, in a big heavy street car and engine without torque will suck. You have to have torque to get that big Lexus away from the traffic lights. You will need to have a high stall converter or an manual tranny.


It can be done, it will not be cheap.

 

[capn]

You need more bore. Nothing wrong with rpm, but it will cost you big money. Why do you think turbos can come out cheaper than an all out NA motor. They are much easier on the engine. A powerful NA engine will require lots of work. You will have to address the valvetrain, long block, induction and exhaust system. In order to accomplish what you are wanting it will take money.

One thing to keep in mind, in a big heavy street car and engine without torque will suck. You have to have torque to get that big Lexus away from the traffic lights. You will need to have a high stall converter or an manual tranny.


It can be done, it will not be cheap.

With this particular car it comes in at a sorta heavy 1250kg, not too much but it is lighter then a LS or SC, and with this project money doesnt matter I want it done right and just once.

it will have a 6speed tranny also, and I am planning on a .020" overbore and high comp

 

[Anaema]

With this particular car it comes in at a sorta heavy 1250kg, not too much but it is lighter then a LS or SC, and with this project money doesnt matter I want it done right and just once.

it will have a 6speed tranny also, and I am planning on a .020" overbore and high comp

thats not too bad. well below 3000 pounds. so i think you can get away with high revs mated to a six speed.

 

[turboteener]

Without doing cams and heads you won't be much over 350. What six speed tranny?

 

[capn]

Without doing cams and heads you won't be much over 350. What six speed tranny?

Chevy T56, I hate word count