Extreme Engine Tech, Technosquare's Monster Naturally Aspirated Toyota 4AG part 2

Great article as usual Mike.
I have a few questions:
Doesn't the TRD logo stamped onto the valve create hot spots?
Would a flat head valve increase the compression ratio? Why TRD did not use it/ or consider that?
Also, when big cams are used (like in this case). The shims have to be replaced to accomodate the bigger lobes. How do you know which shims thickness to use?
Thanks in advance for your time, and keep up the great work!

You all have covered some impressive builds so far... Any chance of a turbo Rotary build-up in the future?

with a build like this being NA. Why didn't they opt to have gas ports incorporated into the pistons to help with gases. Also what type of rings are they using? Nitride steel top with napier second? I'd like to see them use a hell fire ring their next go around.

Great to see this overachievement. I'd like to see the flow bench results from the head work. (For us mere mortals looking to only improve what we have)

Hopefully you'll show what this goes in and what you do with the fuel injection. I'm recommending MegaSquirt as it concurs with my budget.

Some answers to the questions. The hot parts of the valves are the edges, not the face, this is typically the coolest part of the valve. If the valve face was flat the valve would weigh a lot more. Its easier and less detrimental to performance to reduce the chamber volume by other means. As far as shim thickness, these are Yamaha FZR motorcycle shims and its impossible to tell you how thick they would be because there are many variables to that, remember that valve clearance is set with these so the valve depth, wear, etc really affect this.

As for turbo rotary stuff, Eric Hsu is a rotary expert and I am good friends with the Berganholtz brothers so its a possibility, I just have to be in the right place at the right time.

The article has a whole thing on the rings, look up and read. I am noticing that gas porting seems to be falling out of favor for some reason that I am not sure about. It was envouge about 5 years ago. My piston engineer friends say that gas porting greatly reduces ring life and they are eliminating it or greatly reducing the number of ports from previous designs.

Dunno about the flow results but Hasselgen was the premier formula Atlantic Toyota engine builder and they had impressive results. However I was less than impressed with the quality of the porting and headwork on this head. Howard Watanabe of Technosquare was also not impressed and he touched the head up to improve things in the valve pocket a little and unshrouded the chambers more.

We will be featuring the AE86 time attack car this engine goes into sometime in the future.

The engine will probably use 48mm webers although a more modern fuel injection system may be used.

Hey Mike,

i read the portion on the rings but it doesnt distinguish whether or not he is running a napier or not. Ring failure I've seen on boosted applications with gas ports to be more prevalent however on a NA build we have not seen any adverse affects if the proper precautions are dealt with. I look forward to the rest of the build.

Like it says the rings are conventional. I don't think Napier rings are all that common. I think they have issues with oil control and long term life as the second compression ring has some oil control functions. I don't know of any engine builders that use them outside NASCAR, but perhaps Eric might chime in here.

I don't think gas porting causes ring failure, just faster wear. What precautions besides the obvious cylinder wall finish and end gap do you do to prevent problems?

I defer this sort of stuff to my piston engineer friends and don't try to second guess them.

Webers? Go with what you know, I guess.

Individual throttle bodies are available from the 20V 4AGEs, although I am not an expert on the manifold interchangeability. Club4AG.com would be a good reference.

Aside from that, all the other sensors for a good EFI system came with variations of that engine.

Napier rings have the most oil control out of any of the rings used. I only use these rings for both street and race applications. The standard rings used with Wiseco are napier second scraper rings. CP uses a second compression ring for the oil ring with little to no oil control to them. They state they like to run a larger than normal gap to help with oiling issues vs. having a dynamic ring act as the work horse. I personally don't like that. I want a functional ring to work all the time. Believe me I know the engine being built will run extremely well I was just curious as to why they didnt opt to go napier and so forth.

Its kinda odd because it was my understanding that Napier rings are for engines with dry sumps or other apps with sorta dry cylinder walls. I also thought they were for short duty cycle engines as well.

Are you talking about using another compression ring as a scraper instead of the normal 3 piece oil ring???

The engine uses TWM throttle bodies and Autech ECU.

Nope we used them from Nascar/Pro Mod/Outlaw/Drag/Motorsports. CP piston uses what appears to be a second (thicker) compression ring for the second ring. They still utilize a 3 piece oil ring.

I have a 5A motor going together also but using a HKS Crank turns out the stroke is 3.265 instead of 3.267. I have Carrilo rods with 18mm wrist pin. The crank has 40mm mains. good to see all your hard work paid off. I am already planning a 4.5AG long rod motor ha ha
David

A couple points:
1. Cool. So rare to see 4age builds.
2. I think it would be neat to see a tech analysis of the mythical 9age (7afe block, 1zzge 95mm crank, 83mm bore for ~1950cc).
3. As to a possible turbo rotary build, I would look up Mark Warner, as he is a bit of a rotary nut, and turbo book author to boot. And a real P.E.