Cost to build a 500hp FI engine

[turboandrew]

Doesn't look like the 2UZ specs have the rod length. However, if they have a rod shorter than the 1UZ equal to the difference of the strokes, that would be 1.5mm/2 = 0.75mm. That would place the piston 0.75mm lower, or equivalent to having an extra 0.75mm thickness in the head gasket.

I really need to tear apart the 1UZ and 2UZ motors and get exact numbers on this stuff.

 

[Zuffen]

Turboandrew,

By using shorter rods you will muck up the squish area.

The stock squish dimension is critical in controlling detonation.

 

[Lambo]

1uzfe and 2uzfe Specs

Hi Lextreme,
Thanks for posting the specs above they appear to be the same document ie 1uz for both, for a moment i thought i was seeing double, or my computer was broked. or have i missed something here.

Best Regards
lambo

 

[Lextreme II]

oops my bad.. fixed now..

 

[Miles B]

So that motor was completely unopened? ie no new head gaskets or anything? What kind of fuel were they running? How did they stop detonation.

I was thinking about this more.. those short course drag boats see probably 3-5 minutes on boost per meet. There are like 10 meets in a season. Add practice and tuning, and you probably have 1.5 to 2 hours under WOT per season for them. I don't know about you guys, but I'd be lucky to do 1 minute of WOT per week. Plus, would be running lower boost than the boats. So it would take me 18-24 months to rack up as much WOT time as them, with lower boost.

Time off boost is free - the engine is already doing it well. If anything I would think off boost time would be easier with the stock hypereutectic pistons than with forged, as the forged move around in the cylinders a little more at startup.

If I am going to lift the heads, which I am, I don't see the point of not using studs. The stock bolts are single use only, and a new set is at least half the price of studs...

 

[Lextreme II]

For insurance.. i used arp studs...

 

[turboandrew]

Turboandrew,

By using shorter rods you will muck up the squish area.

The stock squish dimension is critical in controlling detonation.

How can you lower compression and not change the squish area?

 

[Miles B]

Dish the part of the piston that is not in the squish area.

 

[tweaked]

miles, on that celica. they didnt touch the motor at all. kept original head studs. With 8 X 1700cc injectors running pump 98, I say they ran it really rich with conservative timing to keep detonation out... at a guess.
of course, ARP head studs are the way to go. stock bolts dont cut it.

 

[Zuffen]

You have 6 options in lowering compression ratio.

1. Thicker head gaskets.
2. Relieve the combustion chambers.
3. Machine the "non squish" area of the pistons.
4. Fit shorter rods/offcentre gring the crank.
5. Fit lower compression pistons.
6. Increase the deck height of the cylinder head by welding and machining.

All methods have advantages and all methods have drawbacks with OHC engines.

 

[Miles B]

tweaked,
I don't see it. Run too rich and the car just doesn't run. If they really did keep the head on the motor, my guess would be they ran C16 or similar, and let it knock.

Dumping fuel in the chamber just means there isn't enough oxygen in there to burn it and power suffers. Too much and it won't even ignite reliably or burn properly.

I wonder about valve float past 15psi too... that's the mystery factor I am worried about.

 

[Pro]

how about

engine - $1200
computer - $2000 (incl tuning)
exhaust manifold - $300 (making it yourself)
fuel system - $500
ebay turbo - $1000
ebay intercooler - $1000
ebay wastegate - $500
underbonnet plumbing (dump pipe, i'c hoses etc) - $200

i reckon i could 'just' squeeze 500hp out of an unopened 1UZFE with 1bar of boost - and i'm going to try soon too

 

[quadcam boat]

That Zoom magazine article had pretty good info on that Celica. I wish I could find it!

 

[turboandrew]

Miles, Zuffen, thanks. I guess I need to read up some more on squish area. I assume opening up the combustion chamber (which looks like it could unshroud the valves a lot) would also muck with the squish area.

 

[tweaked]

miles, cmon.. boosted with AFR's at slightly over generous numbers and timing in the precautios range, the engine will run and make decent power. BUT with that, I heard that the celica possibly ran those times with better fuel. I am not sure of it thought.
Some factors in an unprepared motor are really a 'wait n see' circumstance.
I wonder what mechanical failure in a 1UZ looks like?

 

[turboandrew]

Would be nice to know what boost we could get away with on stock compression on methanol. IMO, I would love to have staged injection, stock injectors on pump gas for cruising and second stage of either methonal or C16 gasoline for WOT

 

[Zuffen]

Turboandrew,

Opening up the chambers should not affect the squish area as long as you do not remove metal from the face of the head. Try a search on the Net, there's plenty there.

Whilst I want an engine to run for many miles without needing repalcement/rebuild I am tempted to try putting the supercharger on tune it with the Autronic (I'm 99% certain I will go that way) and see what happens. I have a spare (good) motor so if the first goes BANG I can always build the second to withstand the load.

From what I have calculated I will have 11lb boost on the pulleys I have now. With 9.5:1 compression I am looking at a real detonation problem. Admittedly it will be intercooled but I still worry about having all that boost and then having to retard the timing which means I am not getting the maximum I can.

 

[1UZ-HZ]

I got the article about the celica in front of me...it was runnin on methanol on the strip

 

[400ZED]

ROd
OZVenom has run 22 lb admitidley that was just over the limit of the stock motor but i am pretty sure he ran 16 lb for a long time reliabley. i think it will hold 11lb. Although i have very little experience.

 

[Miles B]

Methanol sounds right. You need to dump a lot more of it in, hence the huge injectors. Meth burns something like 6 or 7 to 1 instead of 14 to 1.

tweaked,
there is no way you are going to run cautious this, or retarded that, and hold 18psi at 10:1 compression on 98 RON (93 US) pump gas. There is just no way. I would say anything over 8 or 9 and you better watch it carefully. 10 or 11 may be possible with a bit of toluene. maybe 12 or 13 on C16.

I think there isn't much meat left in the head, apart from the squish pad, to drop the compression that way. Might get it down half a point tops, but you're always in danger of water breaking through and spoiling all that hard work.