OST-042-01: The Dubai Deception

[oldeskewltoy]

more to come.......

[oldeskewltoy]

Interesting piston design, turbo/SC build?

The photo of that piston and rod have been up on facebook for 3 days prior to posting it in a forum... in 3 days... it got liked by over 80 people (likely more - I'm still learning fb), and yet not one comment on the interesting piston..... at least not until now......


So lets look at the interesting piston design.... and to make it easy, it is for a S/C build. Dish = 7cc, valve troughs instead of reliefs to minimize potential uneven crown hot spots.



Full squish/quench pads to maximize the action on the charge




more to come.....

[oldeskewltoy]

There is no way that can only be -7CC dish. The actual dish looks deeper than the GZE and then those massive troughs on top of that? There is no way that piston has more compression than a gen 1 GZE.

I was warned about facebook ..... I had these built to my specifications. I told the JE engineer each time I had a change to VERIFY the volume was -7cc... but because I'm an anal retentive SOB... the piston's dish was measured.... AND verified @ Loynings.




This piston took multiple weeks to design. Its primary goal was to offer a "stock" replacement (8.9:1) 4AGZE piston with squish pads which the OEM 4AGZE slugs do not incorporate.... but with a bit more. This design can be manipulated easily to offer from 10:1 on down.



A few more details...







All loaded up and heading over to Loynings with the block, crank, rods, head, and OS valves....




more to come.....

[Rogue-AE95]

Interesting piston design. I like the concept, and I'm curious to hear how it does!

The Molnar rods -- no thrust side oiling hole, or side slot (like the BT rods)? I'm guessing those aren't the custom 40-20 rods that Orion had, based on the crank pictured above. My set of Orion 40-20 rods don't have any thrust side oiling. I considered having a machine shop add (or is that subtract??) the BT rod style side slots.

[oldeskewltoy]

Interesting piston design. I like the concept, and I'm curious to hear how it does!

The Molnar rods -- no thrust side oiling hole, or side slot (like the BT rods)? I'm guessing those aren't the custom 40-20 rods that Orion had, based on the crank pictured above. My set of Orion 40-20 rods don't have any thrust side oiling. I considered having a machine shop add (or is that subtract??) the BT rod style side slots.

regarding the rods, I did recommend a set of silvertop rods, but my client wanted new rods. As to drilling the big end to add a thrust side oiler, most shops say no when I ask....

Are there any aftermarket "H" beam 4AGE rods with a thrust side oiler?

BTW: what's the reason you nicknamed it "The Dubai Deception"? A customer from Dubai perhaps?

As to why the "Dubai Deception" - all I'm willing to say is yes


more to come......

[Rogue-AE95]

As to drilling the big end to add a thrust side oiler, most shops say no when I ask....

Are there any aftermarket "H" beam 4AGE rods with a thrust side oiler?

They won't even machine the BT style slot on the side? I can understand being apprehensive about drilling the hole (matched to the bearing). But I would think even that would be possible from a machine shop.

The Brian Crower 7A-GE rods from Matrix Garage have the BT style slots on the sides (four on each rod):

[oldeskewltoy]

I can understand being apprehensive about drilling the hole (matched to the bearing). But I would think even that would be possible from a machine shop.

not apprehensive.... most "H" beam rods are so hard that drilling them damages the drills, or so I've been told.

As to the 7AG rods with the blacktop type slots, I have not seen that before

[yoshimitsuspeed]

[quote=oldeskewltoy;6577201]
3) As to lowering compression.... @ 9:1, that isn't lower then the 1st, or 2nd gen 4AGZE pistons, it is close to 2nd gen... but as I said it is customizable up to 10:1
4) Why my offering, instead of others.... From reading threads about 4AGZE piston builds, the most commonly mentioned negative was a lack of squish, so along with the volume, the 2nd criteria was an adequate squish. The valve size, and lift determine the troughs, and the remainder of the volume was removed from the crown.[/quote]


So your primary design criteria was to address the issues that people who know absolutely zero about piston design believe is an issue?
The biggest problem with the GZE pistons is their depressing compression ratio. By today's standards 9.6:1 is pretty sad unless you are trying to make 600 hp on pump gas.
Of course if your customer is insisting on staying with a fixed displacement supercharger they will have a lot more heat to deal with which does mean detonation is a bigger concern at a lower power level but that would best be addressed in a number of other ways which I am not going to get into here because well because I can't give you all the secrets. Fixed displacement superchargers hate high pressure ratios. So the best thing you can do for them is keep the boost low and the VE high and BSFC low. Of course if they really want to make power and have efficiency the first step is to ditch the FD supercharger. If they are running a turbo or cantrifugal SC these can handle higher pressure ratios much better but they are also much more efficient meaning you can safely run more compression for a given octane, boost and power level. If you are shooting for 300 Hp you are way better off running 10.5:1. If you are shooting for 600 hp you are way better off running 10.5:1 on E85 or race gas. If that is not possible then yeah you may need to bring your compression down a little but you are still better off keeping it as high as possible and trying to make the power with RPM and VE.
Yes perhaps the GZE piston could have a little more squish but but it's design has already been proven over 600 hp. there are plenty of other low comp pistons out there that offer as much or more squish area as this piston that cost significantly less. Many also have much better flow through the head because of lower domes and less of a wall blocking between the intake and exhaust valves.
Even if you do improve on an design how much effect will it have? And how will you quantify it how much better than something that is already on the market and most likely cheaper?

https://www.youtube.com/watch?v=ml6Lm03QLGs&index=2&list=PLRaE2cL05CyCGF_k2vivKuRZ2e-6SyMtm
I don't know the exact details of that build but it's an MRP 9AG and I believe 10.5:1 compression.

I don't have any pics of our dished pistons because I almost never sell anything lower than 10:1. If someone wanted I could get pretty crazy with squish area though.
If you wanted to get real crazy you would CNC machine the combustion chambers and then design your piston to use as much of that as you wanted as squish area. My pistons are the next best compromise getting as close as comfortable to the cast portion of the head.
Since low comp builds are pretty outdated I haven't focussed much on dished pistons but if we wanted to we could definitely use our basic design, keep much of the above deck squish geometry and just dish the middle of the piston creating some nice deep combustion troughs to improve flow through the head.

Combustion Trough A term used to describe a feature on the piston crown between the intake and exhaust. Ignited air/fuel mixture on flat top and dish pistons typically have better flame travel than a dome piston. Flame travel on dome pistons can be improved with “fire slots” and/or a combustion trough.

http://www.cp-carrillo.com/p-30865-product-features-custom-features.html

But again this is a lot of thought for negligible benefit.

And PS I have no problem owning the quote above about the piston volume. Maybe my eyecrometers need to be checked. Maybe it's an optical illusion. Maybe the design looks like it has a lot more dish. My bad.

[yoshimitsuspeed]

I can understand being apprehensive about drilling the hole (matched to the bearing). But I would think even that would be possible from a machine shop.

not apprehensive.... most "H" beam rods are so hard that drilling them damages the drills, or so I've been told.

As to the 7AG rods with the blacktop type slots, I have not seen that before

You don't want to drill through the rod as it weakens it. Actually drilling through would not be any issue for a machinist but it would not be ideal.
The side groove is very common but it is usually an add on option that you have to request.

BE Oil Squirters This oil hole in the Big End neck allows pressure fed oil to squirt up to the piston and rod Pin End for additional cooling and improved lubrication. This option can be considered for engines without oil squirters.

[oldeskewltoy]

sooooooooooo..... back to THIS build......


Crank and rods are ready..... bearings selected





Blocks, appropriate ones for a S/C build(7 rib none drainback, non notched/20V oil pan), are getting tougher to find. It took me nearly a month to find this one! And while the bores were fair, and standard, this block required .008" removed from the deck because the surface was that poor that it required that deep a cut. I'm using a metal gasket, so since I can size the gasket, the deck is cut enough to provide a good seal




more to come.......

[oldeskewltoy]

using ARP studs




side note, when the block was bored for the new pistons, I was asked what I was planning on using to bolt the head down - stock bolts, or ARP.... different bolts, different torque clamping the two together, different stresses on the block once assembled. The engine is bored using 60#s on the torque plate, instead of the stock 43#s


more to come......

[oldeskewltoy]

THIS is the costliest part of the job..... below is OST-042 in mid surgery. All the original valve seats have now been removed. This requires welding a tool to each seat and then using that welded on tool, to aid in removing the old seat. Once all the old seats are out, the machine work to fit the new seats begins. We see this on the intake side, all new seats, the exhaust side has had the old seats removed, and its waiting for new OS exhaust seats. The intake seats all sit above the deck, once all the seats are in, each one will be machined back to be flush to the chamber. At that point I'll get the head back, I'll do my port work, and once the port work is finished in the bowl areas, the 3 angle will be machined into the new seats.





More to come.......

[Rogue-AE95]

I didn't realize the seats could be taken out. Are they pressed in then machined during the original head production?

[oldeskewltoy]

I didn't realize the seats could be taken out. Are they pressed in then machined during the original head production?

as best as I can tell that is the process

will you do a flow test on this one?

[oldeskewltoy]

The head is back in my possession, all the seats are now installed, and they have each been machined flush to the chamber


(look @ those exhaust bowls and the massive amount of material removal that will be happening)

on the right you can see the first 4 intake bowls have been roughed out, while intake bowls 5 thru 8 have yet to be touched, AND the exhaust have yet to be touched.


A bit closer view of #2 intake cylinders bowls - before, and after




Note the uncut seats.


And after a weeks worth of work.....




Intake short radius's...




and the intakes from another POV....




The intake bowls/ports are mostly finished..... at least until the seats are cut, and I can get it on the flowbench.




more to come......

[oldeskewltoy]

using ARP studs

Since I'm assembling this engine with ARP head studs, the oil passage is over-drilled to accommodate the thicker bolts






more to come.......

[Rogue-AE95]

I thought ARP made that shorter stud also slightly thinner to allow more oil around it? Although I'm sure machining out the hole will improve flow no matter what.

I'll never get tired of seeing your porting work!

[oldeskewltoy]

"Workin" the exhaust side... 3 down... 1 to go





more to come......

[mad_86]

sooooooooooo..... back to THIS build......

Crank and rods are ready..... bearings selected

more to come.......

^^^^HAHAHAHA!!!!


Nice Work OST!! Get down like James Brown, those Bowls look Smoooth!!


.

[oldeskewltoy]

sooooooooooo..... back to THIS build......

Crank and rods are ready..... bearings selected

more to come.......

^^^^HAHAHAHA!!!!


Nice Work OST!! Get down like James Brown, those Bowls look Smoooth!!


.

The head is now ready for its valve job.......




more to come........

[casket77]

Running stock cam's ?

[oldeskewltoy]

Running stock cam's ?

nope....

this engine will be running Catcams 260/230 9.0mm lift cams....

[oldeskewltoy]

So the head is back in my hands, the delay caused by the 2016 SCCA runoffs, and the shop closing that week to support their clients @ the runoffs.


This head is uncut @ 4.566"





and once the valves are lapped into their new seats, chamber volumes can be assessed




3 @ 36cc, and 1 @ 35.9........




1/10 of a cc is pretty close, but because this is an OS valve head, some additional de-shrouding is necessary. De-shrouding is a bit different on an OS valve head then it is on a std valve head. To better utilize the larger valves, a bit more room is needed around the valves....



Using Nissan SR20 valves to protect the new OS 4AG seats, you can see on the right the bit of extra work performed. If you are sharp of eye, you can see the scribe marks to mark out the exact placement of the gasket so I know just how far I can work the corners.....




more to come.........

[oldeskewltoy]

Assembled short block....





more to come......

[casket77]

Looking Good!

[oldeskewltoy]

Looking Good!

thanks!



A peak inside before sealing it up.



adding brand new hardware to a brand new Toyota oil pump, the short block is now finished, just waiting for the finished head.



more to come....

[Rogue-AE95]

I've been meaning to ask, why is this build 042-01? Customer has two builds going on at once?

[oldeskewltoy]

I've been meaning to ask, why is this build 042-01? Customer has two builds going on at once?

Thank you..... I was wondering if anyone would even ask........



The -01 represents the first built block I've been commissioned to build. Although not my first "A" block build, as I have more than a 1/2 dozen "A" builds under my belt, this one was built as a package to go along with the head build - OST-042. So it carries a dual designation, one number in the head, and another number in the block.

[Rogue-AE95]

Interesting. Sounds like a good idea

[oldeskewltoy]

Ready for re-assembly.......





more to come....