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Discussion Starter · #1 ·
Question posted generally for lance, but i finally had some time to sit down with the wrecked head... and it looks to me like it's very restricted just by the angles the air is forced though.

Lance, have you looked at your head much? and what would be involved in a near total redesign? i did take it to the bike shop(of all places, i have a friend who does gaskets for race bikes) his personal opinion was that no real gains would be made of the existing design.

I know it's just pipe dreams, but if my bike makes 130hp off 998cc, then my car should be able to do better than 160 hp. without FI
 

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Yeah, I looked at it quite a bit. It suffers from lots of issues, but to say there's nothing to be gained is a little pessimistic. There's the usual 5 - 7% just from cleaning it up. More than that will make velocity suffer though. At least from what I can see. ZPI claims a lot more for their head, but they also claim you need to remap the fuel to get it to work right which tells me they did something really dramatic to the flow, and I wouldn't call it all good. Most porting gains are incremental, not quantum unless you've completely refocused your power expectations and compromises.

I still need a set of valves before I can get started. It came with a lot of stuff, but valves and buckets were not included.

Something you need to consider about your 998cc engine is how much torque does it make? Where does it redline? Would you want an engine like that in your car? (OK, I would love it, but most people wouldn't, so they won't sell them like that).
 

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Discussion Starter · #5 ·
I'd take it any day also...

the bike is near 85 ft/lbs... on an inertial dyno, the tach stops at 12, but has a variable redline... or i can turn it off all together if im willing to pay for an eneging rebuild all that often. actually, it's a flashing red light not a line... i love bikes, and cars

I guess what he meant, was that it would take a lot of work for minimal gains, and you could easily mis-step and trash the whole thing.

one the 998cc, it does ok in the lower rpms, mainly because it's a large bore v twin... but when you get on it, it goes...

So you think simply cleaning it up could net 5-7%? would it be worth the 8-11 hp you gained?
 

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It would all depend on what else you could do along with the port work. Different cams would be a big plus so you could focus on higher rpm torque and get the torque curve to stay flat instead of falling off the way it does stock.
 

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I'll admit I don't know that much about Toyota engines (or engines in general) and the such so forgive me if this seems absurd, but is it possible to use a GE head from a 2Z?

I would assume not so. It's a little bit of a pity that Toyota engines aren't a little more like Honda engines.

Are there any other 2.4 liter GE heads out there? I'm sure in America there aren't any 2.4 4 ceil engines other than the 1 and 2AZ (or is it only the 2AZ?) so the USDM should only have the FE heads for a 2.4 liter engine but could there be another one elsewhere?
 

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there are no GE heads that will bolt up to the 2AZ as of right now. rumor is, however, that toyota will make the tc into the new celica over in japan, equipped with a 250hp NA 2az... details are just speculation right now and the whole idea is nothing more than a rumor but if/when it ever came out it would likely have a GE VVTL-i head
 

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Originally posted by striptyler@Dec 10 2005, 06:33 PM
I'd take it any day also...

the bike is near 85 ft/lbs... on an inertial dyno, the tach stops at 12, but has a variable redline... or i can turn it off all together if im willing to pay for an eneging rebuild all that often. actually, it's a flashing red light not a line... i love bikes, and cars

I guess what he meant, was that it would take a lot of work for minimal gains, and you could easily mis-step and trash the whole thing.

one the 998cc, it does ok in the lower rpms, mainly because it's a large bore v twin... but when you get on it, it goes...

So you think simply cleaning it up could net 5-7%? would it be worth the 8-11 hp you gained?
"So you think simply cleaning it up could net 5-7%? would it be worth the 8-11 hp you gained?"


Should be doable if done properly
 

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I think there is a good bit to be gained actually. Plus, playing with the cams would do some good as well. I will eventually get one of these heads on the flowbench and start playing with different configurations. Im looking for a blown motor right now to research on.
 

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Discussion Starter · #12 ·
I do say... looking at mine in my free time, the optimal flow path for air, rarely includes sharp turns, and our heads require just about a u turn. does numbers on the actual flow patterns... air on the outside of the bend goes very fast, suffers great frictional losses, and causes a pressure gradient force... which provides very disrupted airflow, all bad i think. Now i know that swirl charging or turbulent air helps mix the fuel better for better flame propogation, but that should not be happing untill the air is actually entering the combustion chamber (the whole swirl charged phenom of the 80's)

i really wish for an alternate verision... i would love to shorten up the piston trave just a tad, drop the deck hight slightly... maybe push the compression up and redline to maybe 7, 7.5. AND a new head. i want it loud, smelly and fast, like a bike
 

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If you can, please do so again and again and start selling those suckers.

The FE head is a fuel economy head, if you can make it into a bike like head, you should be able to heal people with your touch but I'm not sure about turning the FE head into something it isn't..

I wish you a LOT of luck. I want my car to be like a bike, a motor one at that.
 

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Discussion Starter · #14 ·
sure... it just won't fit under the hood anymore, and i haven't the means to make on, but high on my wishlist would be for toyota to do as was described above... a ge head would be nice.
 

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Actually, I'd like the FE head with more upward ports and a hood line to support a straight shot intake. One of the interesting things we see in cars that we don't see in bikes is the concept that a wider included valve angle is considered "performance."

Bikes have been narrowing their included valve angle since the 80's and finding more power because they don't have to fight the hood line problem. Initially they had problems with really high angle intakes because the design paradigm was the gas tank had to be mounted over the engine. They've got better solutions now, and most of the time the space that used to be dedicated to fuel is now dedicated to a huge airbox feeding very straight ports that look directly at the backside of the valves at narrow included angles. Narrow angles do reduce the valve area, but there are lots of other good reasons you can make a lot of power with smaller surface area combustion chambers.

I'm pretty convinced the car guys are just tolerating the problems with the hood line and going for a wider included angle because it makes a better port with the same hood line than a narrower angle with a much better combustion chamber.
 

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Discussion Starter · #16 ·
Yes, as soon as the frame moved to the outside of the tank, it opened up all that space underneath the gas tank for the airbox... which used to be behind the engine. this opened all the space they needed to get it right... i really do just wish that cars would follow suit
 

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Originally posted by SK VR4@Dec 13 2005, 09:50 AM
I think there is a good bit to be gained actually. Plus, playing with the cams would do some good as well. I will eventually get one of these heads on the flowbench and start playing with different configurations. Im looking for a blown motor right now to research on.
i currently have a blown motor from a tc in my garage. would you need an assembled or bare head to do the research on?? pm me if you are interisted and we can make a deal!!
 

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You need an assembled bare head. The head I have does not have valves in it, and valves are an essential ingredient to putting it on the flow bench. Numbers without valves are completely meaningless.
 
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