1JZ performance head build. Advice/help?

[ReQuieM]

Hey guys,

Well I've started on the last stage of my stock turbo build. I picked up a head not too long ago that was already port matched thinking I'd save myself a bit of moolah, turns out it was JUST that, port matched. So the head now matches the manifolds but it looks as if it was just the edges. I'll still need to properly de-bur the ports and injector stub. So not so much of a saving as I thought, tho it does have fresh shims which is a bonus. Also the cambers in the head have had 8cc removed from each, is their any benifit aside from the lower compression? Anyway I've stripped it and now getting it prepped and ready to accept the new guf.

Heres the plan thus far:
Jun Cams 264 or 256
'Performance Springs' valve springs
2JZ Intake valves with low friction coating on the stems and a heat resistant coating on the heads.
Same coating on the stock exhaust valves
Port to suit the new valves, flow and to increase the CFM ingested.


Heres the questions (point of post! lol):
What parts can I reuse in good faith? What should DEFINATLY be replaced? What could be reused but couldn't hurt to be replaced? Things like the steel inserts in the head that hold the head studs? Valve spring seats? Retainers and collets? the arches or bolts (end caps? I've forgoten the name ) that hold the cams in place? Valve guides?

Should I coat the springs in the same low friction, oil attracting coating at the stems on the valves? Is there any real benifit? HPC claim that there are gains to be had, but I'm skeptical.

Due to the extra slippery nature of the coating on the valve steams I want to use the best seal I can. Can any one recommend one? I'm assuming the 2JZ valve stem seals will fit the 1JZ? That opens up a few additional options from OS.

Is there a trick or special way that the valve stem seal should be installed? I've just been removing the fkd ones with a pair of needle nosed plyers. The exhaust ones came off pretty easily compared the shit fight I had to get the intake ones off. Is that normal? Which side was fkd and which was okay?

The stock valves that i removed are looking a little off some of the intakes have what looks like burn marks? white crusted film on them and some of the exhaust valves seam have large deposits of carbon... whats best to clean them? will I ruin any swirl patterning that toyota designed them with if I hit them with a green scrubber and some hard arse degreaser?

While the head is appart should I open the plugs to the water galleries and clean the fk out of them aswell? When reinstalling those plugs what liquid gasket should I use? Is there a special torque they should be screwed into? Or do you just apply some liquid gasket and screw them in till they're flush? I've also removed the half plugs at the end of the cam tunnel because one was loose and not flush. What's the best liquid gasket to use on that?

Also when I removed the cams there was quite a bit of aluminium scrapings/shards/whatever stick in the oil hole at the gear end. I'm guessing by that, that the head wasn't givin an awesome clean before reassembly. What's the best what to make sure all that shit is cleaned out? High pressure washer and degreaser?

When I'm deburing the head, is there anywhere that I can lightly port to save myself some dollars on the flow bench? Like knife ending the airflow spliter? the outer parts of the outermost exhaust ports?

Finding valve seats for the 2JZ intake valves has been a bit of a pain, I haven't ask if the guy that will be matching and porting the head if he can get them, but if I don't find any will it be fine to port machin the 1JZ seats to fit the larget valves? will I be losing valuable air flow? I'm assuming that the port job will open the hole out to accept the better flow available, but you know that happens when you assume. Maybe Dori-Dori (I think it was him that had a similar set up on his race/drift 1JZ) can help me out with this?

Also rather then just buying standard sized 2JZ intake valves I thought about going the +1mm ones that are available like the brian crowers etc. What size valves could I comfortably fit? There seams be be plenty of clearance between the valves, although will they come close to hitting in the overlap period? Would I be OVER valving the head with +1mm's? With the 1JZ's exhaust valve being larger then the 2JZ one (IIRC) would I just be settign up a better valve ratio? I've heard that the rule of thumb for the V8 boys is that the exhaust valve should be about 75% of the intake one,going by the decrese in size of the air in the combustion chamber ignition. Is the same true for a forced induction engine? Or should I be looking at a larger exhaust valve as well if I go a +1mm on the intake?

Stock Valve rations
1JZ I 32 mm x E 30 mm = ~93%
2JZ I 33 mm x E 28.3 mm = ~86%
Any others peeps can think of?

My proposed set up (+1mm)
I 34mm x E 30mm = ~88% So that should be gold yeah? or should I be looking at a ratio closer to 1:1 for a FI engine?

Am I going to getting more lag (or sloppier response) from the larger valve setup? I would assume the cams would have more to do with it then the valves but theres that ass word again!

Anyone with experience with the 264 Cam? How much bottom end did you lose with it? a little? a Lot? I'm trying to decide whether the 256 is too small a jump or whether the 264 is too big...

Yeah I guess thats it for the moment. If any one can help out in any area pipe up, I've got rep burning holes in my pockets!

Cheers

[ReQuieM]

OH one last thing that I forgot, in an article I read on supramania I think, they talk about NOT port matching the exhaust ports to the exhaust manifold. Apparently it causes a lose of low end torque. Heres the exact 'quote' from the article:

"Opening up the exhaust ports on the head removes the reversion dam and will cause you to lose torque because the manifold will no longer scavenge the head"

Thoughts? I thought that the pulses would occure BETTER with out the intrustion rather then with?

[celicapain]

biggest post ever? (soz me know nutting)

[ReQuieM]

WHOO! I got a reply! YEAH! lol

Yeah sorry about the length But I though one post rather then 20,000 would be better.

[kingd]

dont re-use collets... cheap insurance for not dropping a valve
if the retainers arnt worn badly enough to feel a step they should be ok
valve stem seals should just slide over into the groove with abit of lube
just buff the valve head (not the stem) on a wire wheel to clean them up... if the valve face isnt pitted should be OK once they are cut but check the valve stem for wear with a mic (any more than about .02 - .03 of wear is probly abit much)
when the head is off it is smart to pull the core plugs/grommets/etc and flush it with high pressure to make sure gallerys (oil and water) a thoroughly clean. Kero can help, also chucking the head in a robo always helps.

[ReQuieM]

Yeah I was thinking that about the collets, Do you think that stock replacement collets and retainers will be fine to use? I've heard of race teams using titanium and standard steel ones, Titanim for weight savings and steel for better wear resistance, with no probs. Are the stockies steel? I'll try a magnet against them tonight and see.

By a step in the retainer you mean a groove created by the springs yeah? Cos they've all got a step! lol

Thanx for the advice!

[BMWTurbo]

Didn't you get collets and retainters with the springs???

I got retainters collets and springs from performance springs...

[ReQuieM]

I haven't picked them up yet and I didn't want to assume that I would get them with the springs. To much goes to shit when I start to assume shit like that.

But thats good to know.

BTW I got pricing back on the valve and spring coatings. For only about $3.30 odd I think I might as well get the the springs coated. They claim that it can increase the springs shape retention by about 3x. Not that they will probably see a life that long but it's nice to have. Especialy if I start racing it.

[ReQuieM]

Bump, Still chasing this info... Cheers.

[kingd]

Bump, Still chasing this info... Cheers.

what specificaly.. might be able to help..

[ReQuieM]

Just all the stuff up top I guess. Just some tips on rebuilding and advice on the performance recipe. Things like the valve ratio are what I'm really keen on.

Also can anyone confirm that over 9mm lift makes the 1JZ an interferrence engine? soarercentral second hand info. Stupid questions probably but what does this mean for me? I know I will have to be careful when I reassemble, but anything else?

Any thoughts on what my new rev limit would be with the proposed set up?

Cheers!

[jeffro ra28]

Lets tackle this one thing at a time aye.
Firstoff, good to see your taking really good interest into and real good attention to detail about the whole afair.

The 8cc removed from the cylinder head chambers was most likely to do reshaping the chambers to maximise flow. The steps leading into the exhaust valve are usually removed here to gain flow.

Coatings, i have absolutely no faith in them wat so ever. I would save your $$$ and spend it on somthing that counts. Trust me, it means jack shit. IF your were talking v8 supercar, total reliability and every ounce of performance then perhaps it has merit, However this doesnt seem to be the case.

Valve ratios dont mean a great deal to me. Flow ratio means alot. For turbo'd engines a intake to exhaust flow should be 80-85% that is, the exhaust flowing 80% of the intake flow.

Stock retainers and collets can be used time after time after time. Unless the thing has been bounced of the limiter or flogged, the retainers should be in top notch condition. Just check for the step the spring may have left.

Do not worry about the swirl pattern on the valves. This doesnt mean a thing in regards to the performance of an engine. Although they claim to, its just a sales pitch. At work we have proven this to be false with the use of a dyno!

Ill answer more questions tomorow

[ReQuieM]

Man you are the person I've been waiting for! Awesome info!

I'm hanging with baited breath for the next instalment!

[ReQuieM]

I know theres alot other stuff there to answer but if I may ask another, Whats the best way get that flow ratio? I was assuming if the ports were ported to match the valves the valve ratio would be th one to go by... Is porting then hitting the flow bench the only way to get truly build/port the correct ratio? Would using valve size be the best place to start and then port to suit or port and then work out the best valve size?

Cheers again!

[jeffro ra28]

To me valve sizes mean nothing, potential flow is hardly anything to do with valve size. Simply because majority of the flow for the exhaust port can be gained from chamber shape. Try and picture a combustion chamber, then the exhaust valve being a funnel. The more funnel affect you can get on the exhaust valve the more air can be pushed out of it in one stroke. But obviously we are limited as to how much of a funnel we can create due to the other factors which affect the peformance like flame travel, compression etc.

The only real way to do it properly is to flow the head on a flow bench. Ports may look nice but are crap. Huge ports look good but are often very bad. Air velocity in alot of cases is way more important then actuall flow. However with supercharged or turbo charged volume of the port is also an important factor.

If it were me in your situation, i would be leaving the ports as stock design, with stock size valves. But have the valve seats machined out closer to the outer edge of the head of the valve. Which is actually giving it the "big valve" affect. Then bring the ports out to very close to the valve seat. Cleaning up the ports and port matching is also very important. But there is plenty more to do with ports themselves and chamber to gain HP.

Ill tell you now that you WILL NOT notice a difference in repsonse if you change valve size. You will however if you change the shape of the ports or make them considerably larger.

Please tell the specs of your cam @ .050" lift. Advertised duration means basically nothing to me.