Oversized intake valve in a 1JZ?!

Dave in his never ending quest to see the 1JZ as a performance powerhouse takes a hard look at the intake valve size and finds out that there is a better alternative to the oversized valve for this platform!

[Otto_Factory]

HeadGames and The Motor Oil Geek are my top 2 channels for legitimate information dealing with engines. Its so nice to have professionals in their fields put out tested information. 😎😎

[petertubez]

I can't add pics, so I'll email you the data. It's a replay from work I did 20+ years ago on Peugeot/Citroen XU9J4 heads. Standard inlet was Ø34.5 and flowed 211 cfm @ 0.3". I tested four Ø36.5mm valves (5, 10, 15 and 20°). All worse than oem <0.3". Port them properly though, and the 10º valve yielded 225 @ 0.3", 278 @ 0.4" and 296 @ 0.45". Also better or equal to oem < 0.3".

[patrickoleary]

Thanks for taking us on this journey Dave! I had an idea it might be all hype. Just no testing on it. I commend ya on showing all this. You easily couldda said, it’s not good I tested it, but you went way above and beyond. I app that a lot brother!! Awesome job as always. Crazy how far this has come from the old NOPI Nats and Old Englishtown Days!! !! Wild!!!!

[goyocarreras]

This is great, I came from watching your podcast and now I found a video on your channel, this is a HeadGames Motorworks session.
I love listening to you even if I don't understand you, and reading everything you say, congratulations on your new CNC project.
Best regards
Goyo

[GTRliffe]

i like how he tells you to spend less sometimes

[JesseS]

Great video and information. Loving these flow test comparisons. It would be interesting to see what kind of flow you could get out of the oversize valve with a port and polish. Maybe that would make a big difference.

I know you have a bit of bias against 1JZ heads and 1.5JZ platforms as you mentioned. I get that in terms of trying to make big power and the cost of a 1JZ in the US.

I moved to Thailand from the States, and the prices of 1JZs are incredibly cheap and plentiful here. You can buy a Nissan Cefiro or E36 BMW with a 1JZ-GTE swap for around $3000.00 for the entire car. Also, you can pick up the motors cheap enough too. You can get a complete 1JZ GTE for just over $1000.00 here. At that price they make very affordable and reliable power. If the lower end blows up, you can pick up a complete 2JZ-GE for $300.00 - $400.00 here and do a 1.5jz cheaper than you could rebuild or get another 1JZ-GTE.

I still like the idea of grabbing a 2JZ-GE VVTi and putting in a set of rods and pistons in that. It would be a better platform for big power and good torque throughout the entire RPM range.

Please keep these videos coming. They are very informative and entertaining.

[madunwerkstatt]

I wonder why would anyone put oversized valve without actually doing full porting job to optimize it.

[zedhex]

I always thought the main bottleneck in the 1JZ non-vvti head was the exhaust port. Will you be doing any videos based on that?

[TheSol]

The std 1jz with valve works. The first test was the best. at 250 green line

[TheSocialPraxis]

Can you do a port and polish in the 1jz and see if gains are work the cost? 😁

[evanormous]

Do you have any experience with an M54 head? Wondering if any gains are possible… already forced induction and wondering if I gasket match the exhaust if there’s anything to be had. Love your stuff Dave!!

[tomorrowsmidnight]

Will you guys eventually do a video showing the advantages of replacing the 1jz intake seats with 2jz seats and blending the bowls to support the bigger 2jz valve? Or is this "bigger valve bad" going to be the end of the 1jz content?

[azizkhan]

This is great info, next up is to compare this data to a pocket port or full port and supertech valve

[tlovsoe]

i really appreciate the metric measurements. Why do the ports curve?

[shaunmccreedy]

Have you used the ferrea hollow valves in a build yet? I believe they 20% lighter than std valves but also cheaper than titanium valves.

If so would you recommend them?

[malloymotorsports]

Love your work. Question. I'm doing a Mercedes turbo 190e build using the M103 engine. sohc, inline 6 cylinder. Would you consider porting a head if I send one out?

[myrx]

This is one thing ive been unsure about while getting my new motor build. Although its 2.0 tfsi vw motor and aiming for 600+hp ive spoken to a few different workshops about stock size valves and oversize none of them can actually give me a solid answer as to which way to go. Same with porting

[spiroskatsikas]

Then maybe try a smaller head valve and flow test that,

[turbo.yota.]

What about an oversized super tech valve?

[Badassracecarcpt]

This is probably a dumb question but I've been thinking of fitting a 2jzge vvti intake cam in a 1jzge vvti head. Is it possible? I'm running n/a so I want to play around and see what I can do just for some gains before I purchase a 2jzge bottom end.
Is it possible?
What all must be done?
Is it worth it?