Need advice (and maybe a motor) PART 2 - BOUGHT A MOTOR

[kc95sc400]

Hey all.

So after going down a dragstrip with too much timing I have 2 cyls with low compression. I think its either the rings or the lands. I'm definately losing pressure into the crank case and it smoke quite a bit if I push it at all. I bought a used motor to build since the car still runs ok. The motor was SUPPOSED to be a 92 but turns out its a 95. From what I can tell it DOES have the THICK rods however. I have not actually pulled out a piston / rod yet to confirm but have measured the small end thickness as best as possible with the short block intact.

I actually have had the motor for about a week now. Have it torn down to the bare short block at the moment short of removing the oil pump and rear main seal retainer. Have hot washed the heads, upper intake, lower intake, valve covers, oil pans, ect....

I am struggling with the idea of getting some pistons for it. I don't think I will get rods since I'm pretty sure I have the thick ones. I've been eyeing the Ross 99733 pistons (google it). Any advice would be great here. I am also considering just pulling out the pistons, honing the bores and installing new rings. If I get pistons it will be off to the machine shop.

I have ported the lower intake to match the gaskets. I intend to port the upper intake as well to match the gaskets. I have ported one head to match the intake gaskets and intend to do the other. Will probably at least polish the exhaust side. I have installed 8 small water meth nozzles to the lower intake. Should be interesting. I intend to flip the upper intake and valve cover gaskets to get the throttle body closer to the supercharger.

I intend to get rid of the IAC valve and use a Bosch 3 wire valve. This is mostly to free up some outputs from the Adaptronic. Also going back to using a bypass valve.

I am going to replace EVERY seal on the motor. Already have most of them. Have a set of Cometic HGs on the way, standard thickness. Have removed the valves and intend to clean and "lap" them. This thing will be pretty much brand new by the time I'm done with it.

I'm not sure if I'm going to use the wiring harness that came with the purchased motor. I'd like to since the engine has to be about half way torn down to get it out. I'd like to have the motor as ready to put in as possible before removing the engine currently in the car. But there are a ton of broken connectors on it and I'd have to do some re-wiring on it to make it work with my setup. Not really a huge deal but time consuming.

Theres some more bits but thats the most of it I think.

Right now I'm just struggling with what I want to do as far as actual upgrades. As said, I'm really considering pistons. Would be a wise investment. I've been talking with a machine shop who seems confident that they good handle the job. Also looking at cams and valve springs. Also looking at aftermarket throttle bodies.

I don't need it to handle 1000hp but I would like to never have to do all this again.

Let me know what you all think. I'll try and take some pictures soon.

Thanks,

KC

 

[kc95sc400]

Alright, quick on some pics. The actual motor is at work so no pics of that but here is the:

Mostly disassembled heads...

Port on the heads.....

Porting progress on the lower intake, the bottom ports to the head are by far the worst....

Painted lower intake with nozzles installed. The rubber hose is for heat insulation....

FYI, not going for perfection on the porting. I'm not an expert by any stretch. Just trying to open it up a little. Advice welcome......

KC

 

[stevechumo]

Go for lower compression and forged pistons. I think they're worth the money.

P.S: My previous engine from a 95 SC has skinny rods. I think that the rods have 2 sizes for the 95.

 

[Lextreme II]

That sucks.....

 

[spf_lexus]

KC, you might want to consider one of these:



This will open up a tremendous amount of top end flow whilst preserving the lowend tq. SLap pone of these in there turn down the timing and you'll still make more hp. Just my $.02. BTW, port work looks pretty clean.

 

[kc95sc400]

KC, you might want to consider one of these:



This will open up a tremendous amount of top end flow whilst preserving the lowend tq. SLap pone of these in there turn down the timing and you'll still make more hp. Just my $.02. BTW, port work looks pretty clean.

So, when are you going to make me one?

Just purchased a set of Ross 99733 pistons.

Go for lower compression and forged pistons. I think they're worth the money.

P.S: My previous engine from a 95 SC has skinny rods. I think that the rods have 2 sizes for the 95.

Ok this is VERY easy to figure out. Go to lexuspartsnow.com. Pick 95 SC400, engine parts, crankshaft and piston. Number listed on the picture for rods is 13201. Now scroll down to where 13201 is in the list. Notice that there are TWO part numbers. 1 for production date from April 1991 to August 1994 and 1 for production dates August 1994 to March 2000. My guess is this is when the switch is. The production date of the car that my NEW engine came out of is July 1994! I'm pretty sure that my original / current engine has the skinny rods but I have not yet checked the vin.

KC

 

[spf_lexus]

So, when are you going to make me one?

None yet! but im working on it. Right now I am half way done converting a stock mani to the picture above. Justin_gt8 built this one and pretty sure said he had the CAD file on hand if anyone wanted ro build one. Justin is one of the best examples of insane hp from minimal boost and he swears by these. If you have a spare mnanifold, all you need to do is mod 2 runners at a time so you can keep the upper manifold flange in place to keep all the alignment exactly as stock. Upsize the runner a bit and tig straight runners in place of the crossover J's.

I really hope someone finds a way to adapt the VVt manifold to early UZ heads. Its the best swap around and will make more power across the entire curve but until someone engineers a cut & weld-on adapter, its still an idea.

 

[kc95sc400]

Alright, stupid question.

Bought a set of Ross 99733 pistons. 8.5 compression and a diameter of 3.465 versus the stock piston which is 3.446 I think.

Is it ok to bore the block to make these pistons fit???

KC

 

[Lextreme II]

Did u check the block before buying? If the pistons are bigger, you have to bore...

 

[stevechumo]

Alright, stupid question.

Bought a set of Ross 99733 pistons. 8.5 compression and a diameter of 3.465 versus the stock piston which is 3.446 I think.

Is it ok to bore the block to make these pistons fit???

KC

That's not too bad. It's only around 0.5 mm bigger. Bore it out.

 

[bartledoo]

Ooooo lower compression ... More boost

 

[stevechumo]

Khris,
Any updates on this?

 

[kc95sc400]

Khris,
Any updates on this?

Yes just been too busy to post about it lately.

Having a machine shop build the bottom end. KT Engine Development in Concord North Carolina. This might be their first 1uz (maybe not) but they are very knowledgeable and are mentioned quite a few times in Hot Rod magazine.

Crank has been balanced and polished. Block has been cleaned, bored and honed for the Ross pistons. Using OEM rod bearings and ACL mains (long story). Using the stock rods. Confirmed that they are the thicker rods.

I have cleaned up the oil pans, valve covers, heads, intakes and everything else. I had the heads resurfaced and have put them back together, all clearences are good. Have port gasket matched the intakes and the heads.

I am totally re-working the wiring harness that came with my used motor. Taking out everything I don't need. Repairing allot of broken wires. Replaced about half of the connectors. Re-looming it and such. I have been totally shocked in the poor condition the wiring was in but it should be great when I'm done with it.

Theres more.

KC

 

[kc95sc400]

Ok updates:

Crank balanced and polished.
Block cleaned, bored and honed 20 over.
Ross 8.5 pistons installed.
Block resurfaced.
Heads resurfaced.
Intake side of heads gasket match ported.
Upper and lower intakes gasket match ported.
Cometic head gaskets.
New just about everything!
Port water meth injection.
Intake manifold is going to be flipped most likely.
Wiring harness totally gone over and re-done.
Megan Racing radiator.
New, dual 14 inch fans.
140 degree thermostat.
Bosch 3-wire idle valve.

That's most of it. I have the motor 95% together and ready to put in. I need to swap the injectors, supercharger, coils, wires and a few other newer parts from my current engine (which is still running fairly well) to the new engine. Will still need to do a bit of wiring once everything is in.

Plan on this weekend as I have Saturday, Sunday and Monday off.

Anyone have any recomendations for oil to use for break in?

Will try and take some pictures.

KC

 

[cribbj]

KC, how is your timing belt tension after surfacing your heads and decks?

If it seems to be a bit loose, be sure & check your cam timing with a degree wheel.

Also, have a read of this article: http://www.lextreme.com/Cam-Timing.html

For the break in oil, I've been using the Brad Penn 30w break in oil on the last 4 engine (re)builds and like it: http://www.amazon.com/Brad-Penn-009..._1?ie=UTF8&s=automotive&qid=1307408298&sr=8-1

The Brad Penn oil comes from a Pennsylvania grade crude and is refined at the old Kendall refinery. In effect, it's a 21st century version of the old Kendall oil. If you're 40 or younger, you probably won't remember this oil, but it was the very best oil available for the muscle cars and sports cars of the 60's and 70's.

Joe Gibbs and Royal Purple have jumped on the break-in oil bandwagon now too, and are offering their own versions. No idea about these.

Watch your oil pressure closely the first time you fire that puppy up. The 1UZ oil pumps are known for losing their prime and becoming air locked. I've had it happen on 2 rebuilds, but thankfully I had prelubed the engine before starting, so no damage was done. If I were you, I'd remove the oil filter, and back fill the oil pump with some oil, then refit the oil filter. This should help the oil pump to "catch" its prime faster.

 

[kc95sc400]

The timing and tension seemed fine. I was a little worried cause I had already read your article on it.

I was told 6 thousandths off the heads and I'm not really sure on the deck.

Thanks for the advice on oil and priming the pump. Does the inner hole of the threaded portion of the filter housing go to the pump itself? I work work in a shop with pressurized oil in the pull down reels and it would be easy enough to do it.

 

[stevechumo]

If the timing marks are aligned not too easy, and not to hard with the tensioner being tightened, then it should be good. Too easy = low heads. Too hard = high heads.

 

[spf_lexus]

After a second head/block machine job I had a lot of slack in my tensioner, I had my builder weld a valve lash cap on top for some extra tensioner length, worked like a charm. Also, when the heads are done a few times both water bridges wont fit and the holes will need to be drilled out wider to fit over the mounting studs.

As for break in oils, diesel is a nice choice as it has more zinc content and in general has to deal with higher temps and more wear than std oils. I use synthetic 5w40 delo all year round (no cats of course).

 

[cribbj]

Thanks for the advice on oil and priming the pump. Does the inner hole of the threaded portion of the filter housing go to the pump itself? I work work in a shop with pressurized oil in the pull down reels and it would be easy enough to do it.

The inner hole goes to the oil galleries of the block, it's the outer one that comes from the oil pump.

If you have pressurised oil available, you may want to consider prelubing the block & heads, unless they're all coated with assembly lube? That nipple that the oil filter screws onto is a 3/4" x 16 thread (which so happens, is the same as an -10 AN. If you could build a hose to adapt your pressurised oil to that, you could then prelube the engine before you start it.

 

[kc95sc400]

The inner hole goes to the oil galleries of the block, it's the outer one that comes from the oil pump.

If you have pressurised oil available, you may want to consider prelubing the block & heads, unless they're all coated with assembly lube? That nipple that the oil filter screws onto is a 3/4" x 16 thread (which so happens, is the same as an -10 AN. If you could build a hose to adapt your pressurised oil to that, you could then prelube the engine before you start it.

Well I'm pretty sure the machine shop used plenty of lube, can smell it and it was coming out of the main oil galley in the block at one point.

I put the heads together myself and coated everything with mobil 1 supersyn. I DO NOT intend to use mobil 1 for break in its just what I had laying around to coat everything with.

I may take the valve covers back off to double check everything and to pour a quart or two of oil into each head.

There are two plugs on the oil filter housing. I took out the top one and fed oil into it via my pressurized line. This went into the oil pan so I'm assuming that the top hole goes through the pump, into the strainer pipe and into the pan.??.

The bottom hole had too much back pressure and I couldn't get the line to seal well enough to do much of anything other than make a mess. I'm assuming that the bottom hole goes the the main oil galley. I suppose I could be backwards in my thinking here. Maybe oil won't go through the pump when its not moving?

Anyway, I'm fairly confident that things are lubed.

KC