Porting and polishing heads on the 1uz's..

[jibbby]

Right on fellas:beerchug:

 

[lexhere27]

How is the port matching coming along?

 

[jibbby]

It's not...Too much trouble removing the heads and all for such little power gains from port matching... I've decided pass on port matching until one day when I do remove the heads for some other reason...

 

[4000GT]

I just brought some spare ones for some porting fun

 

[jibbby]

4000Gt did you ever port those heads?

So what do you guys think? Is it a good idea to try and port and polish the heads on the early model 1uz-fe motors? N/A or Boosted? Do you really think there will be a noticeable difference when done right?

 

[cjsupra90]

Jibby, If other parts of the engine are matched, then gains can deffinitly be seen. Remember, the heads are just one part of the entire system, thus if the intake or the exhaust cant flow what the heads can, then there is your limit. Example, you might design and build a good flowing intake and exhaust and only gain 10 to 20hp but properly port the heads and all of a sudden, gain 50 to 60hp. This can also happen in reverse, you might port the heads with a stock intake and say good exhaust and only see 20 to 30hp. There is also the factor of where you want the power (what rpm range). Whats good for one, may not be good for another.

Just remember, its the entire package, not so much just one part of the package.

 

[4000GT]

Hey mate,

Yeah got the heads, had my mate port it (not too insane)... gains noted on link, also have the print out somewhere.

http://www.youtube.com/watch?v=-HwSZSdCczI

 

[pull_85]

my heads will be coming off in next within a month or so and ill be looking at doing something with them

 

[jibbby]

Ok, now I would think a cam upgrade should be considered first and then porting the heads as an increased cam lift would only accomadate the head work, right? N/A speaking....

With the kelford cams you gain 40-45hp which is comprable to the VVti system, as stated on their website.. My concern for years has always been with the cam upgrade you gain mostly highend power with some mid range gains, now with the head work which also helps with increased topend or high rpms flow I would think the lowend power and torque would greatly suffer.. N/A speaking...

On a personal note.. I know when I changed out my stock headers to S&S headers and deleted my cats I lost some lowend juice.. Prior to the headers I could spin the rears half way thru first gear with no nitrous, then after the exhaust upgrades I lost maybe %50 of the burnout time in first gear..However, very good topend power was gained... Now with the upgraded cams and ported heads in combination with the headers and highflow exhaust what will that do to the lowend torque and power? I would surely hate to have gutless car out of the blocks and that has always been my biggest concern to these mods.. Even worse bog at launch...

Any thoughts on this?

 

[cjsupra90]

Most likely yes, there will be a loose of low end torque with those upgrades...... Remember though, mid and top end torque is what makes a car faster one you get into the power band..... More torque at higher RPM's = more work in a shorter time and thus faster car.

Most of the time, you can gain in one area but at the expense of another area. You cant have both, unless you have VVT, VVTi, VTEC, NVCS, ect.... (i.e. Variable valve timing) then you can have just about the best of both (all) worlds... This was the whole point behind these systems....

 

[jibbby]

Yep, Cjsupra90 my thoughts exactly, thanks for the reply......

 

[ed_ma61]

riddle me this jibby - my uz makes more power over stock through the entire range, despite porting, cams, etc etc etc

 

[jibbby]

Wow, Ed that is so enlightening....So does my UZ, woopdee dooo..... SOooooo ED what's your point if you have one? What does this have to do with porting the heads on a UZ?

To answer your weak arse riddle mate, maybe you bored the block bigger, and or possibly are riding nitrous.... Come on Ed you can do better then this...

 

[ed_ma61]

My concern ... with the cam upgrade ...with the head work ... the lowend power and torque would greatly suffer..

my point? youre wrong

most unusual

sure if you build a 'bolt on' engine without giving anything any thought, paying nil attention to port velocity, manifold tuning, cam timing and piston velocities, with mismatched manifolds being run by a stock ecu (or equiv crap piggy back) youll get a rubbish engine

thats why i laugh at the general 'speed shop' approach to 'kits' and 'bolt ons' which effectivly do SFA. yet people will trip over themselves if a new 'kit' becomes available. lol

show me the engines that are *actually* making power. an no, nitrous and forced induction dont count

 

[jibbby]

That makes better sense ED...Good explaination... I will always give credit where credit is do...

How does one pay attention to port velocity, manifold tuning, can timing and piston velocities if your just a normal Joe? For a guy like me you can get an idea, hire a good tuner to adjust a piggy-back ECU accordingly.. When porting the heads you send them out and get them back from a pro shop, they port to their proven recommended specifications.. Cams the same, you tell them what you want and trust them to deliver the matching cam specs for your setup.. Again those are prefabbed spec's on the upgraded cams aswell...

Timing at higher Rpms is an ECU matter which most piggy Safc's just can't handle.. That's another problem unless you are working with the SMT's or stand alones that are capable of advancing or retarding timing accordingly.....

However, if you get all the work done at quality shops, (heads, cams, etc.) and then get a good tune job I was hoping that would be good enough... This was my concern and why I started this thread... I would love to aquire an even power band with these mod upgrades.. Hmmmm?

It was never that complicated when trying this stuff with the older iron block carburated Chevy's.. A couple of cams and not four, a tweak here and there with the carb adjustment, Excell distubitor, MSD, etc.. It was so basic and easy and always seemed to work itself out.....

 

[ed_ma61]

http://www.toymods.net/forums/showthread.php?t=27535

 

[JBrady]

Ed,

Your technical article post on head porting is excellent reading and a good collection of information on the subject. Recommended reading for those that want to learn some of the variables and theories. Huge subject but nice post.

http://www.v-eight.com/tech_forum/viewtopic.php?f=39&t=576

To wet the appetite of Lextreme readers... here is one of the visual models from Ed's post.

 

[JBrady]

Jibbby,

The subject of porting is a MASSIVE topic with many competing theories.

To take an extreme simplification: When MOST people hear the word "porting" they think of grinding away metal to make a port bigger with the belief that bigger will flow more. USUALLY bigger also means lower velocity and that USUALLY means a loss of low RPM power.

ONE of the actual reasons to modify a port is to increase its efficiency so it will flow more under ACTUAL operating conditions. An increase on the flowbench does NOT guarantee this will correspond to an increase in actual flow and or power when running on the engine.

Consider porting a carburetor. You can increase the flow capacity without increasing the diameter of the butterfly valves. This is increasing the air path efficiency through the carb.

Minor changes with MINIMAL metal removal is often the best approach. In fact some ports benefit from adding metal (welding in metal and blending to achieve a new profile) effectively making part of the port SMALLER.

Just because someone owns a grinder... heck, even someone that has been "porting" for YEARS does not make them an "expert". Many people do the WRONG thing all their lives believing they are doing the RIGHT thing!!!

There seem to be very few people that really understand what is the best thing to do with the 1UZFE heads from the perspective of porting. Even less that understand from the aspect of a street engine that is primarily used for everyday driving. On many engines some VERY small changes can make a HUGE difference in performance. Believe it or not on almost every engine the first thing to address is in fact the valve job. This means optimizing the relationship between the many angles of the valve and the seat. This is step ONE of porting. The valve "job" is in and of itself is a massive subject. Optimizing porting is a major area of study where some of the best minds in the business often disagree.

 

[jibbby]

Ed, that was very logical and informative thread link you posted up on how to create power in an engine.. Even with Laymans terms which I can personally appreciate, thank you... While I agree with just about everything you say in that post of yours I do want to point out an error I believe you made.. I agree matching up ported heads to after market performance cams is very important to get the most out of both mods or visa vera, but to say one will not benefit without the other I believe is incorrect. Example: I have installed performance cams without any other mods on stock Chevy engines and have seen noticeable gains at topend while still using the same stock Chevy heads and flow. Also Kelfordcams.com claims noticeable gains by only installing their cams on a stock 1uz-fe N/A engine without any additional head work or any other mods... So gains can be made just with one mod like head work or just cams alone, right or wrong?... However, the best and most effective plan would be to match and port the head flow to the after market cams to benefit the most from both mods as you stated.. That I totally agree with you... It's just hard to do that as a novice or a normal Joe.. Most can only afford one mod at a time on street rods, so matching one mod to an undetermined future mod can be very hard do...

JB - I am fully aware that just grinding away material to create a larger flowing area can be counter productive when porting heads..... Same philosophy as putting 3" mandrel exhaust rather then 2.25" mandrel exhaust on a SC400/Soarer N/A... The 2.25" will always flow more effective on an 1uz-fe motor N/A as you have stated in many of your prior posts..

For the longest time I had always thought bigger and or no exhaust is the best exhaust but as proven that is not always the case..

This is why I think one should consider a pro head porting shop that is familiar with the engine and head flow for the desired engine and application and or future planned mods... If you just plan to install cams on a stock 1uz.. engine and never plan to have head work done then you can find the proper cams to match for better flow over the stock cams...I would think the same will apply with the headwork even if you never want to touch the stock cams.. Right or wrong?

Nice informative posts and links though... I did learn a few new things as there is basically a real science behind all this... Matching everything up as a normal Joe can be a difficult feet, so let's just say most of us just go by what companies claim with their performance mods.. For alot of us this is not pro circuit race car setup we are trying to accomplish but just looking for some good gains with each mod on are street driven cars..Matching each mod to another perfectly is almost impossible...So we buy these performance parts from various companies at different times, test, install and hope for the best possible gains and matches anyway.. It does not always work out but most of the time it does especially with the bolt on mods.. Atleast I can say that's been my experience with various mods...

 

[XR8tt]

Any cam grinder or head porter should have a spec sheet like this to fill out.... I would say for the n/a home porter.. A good polish would make alot of difference especially around the port divider, making it sharper...
Ahhh I don't know how to convert office file !!!
But its a cam spec sheet you fill out with intentions car / engine is being used for, transmission, gearing, body weight, head flow numbers, compression etc...