Long rod 4A or how to destroke a 7A

[oldeskewltoy]

there is no longer a need to go above 10,000 rpm... I can't speak for Hasselgren but I've seen Loyning 4AGs plant well over 260hp UNDER 10,000 rpm.

[Mjh]

Any updates on this thing?

[bermy]

It's comming along... slowly though...

Block looks like this



I decided to use 7A timing component (yeah I know, why do something simple you say? It's that whole engine build story). So it requires a 143 tooth 8mm pitch curvilinear belt 20mm wide (same as a 2JZ but a little narrower). Had to order it from GB and it didn't land here yet.

The water side is done



I still need to plate a bunch of stuff like alternator bracket and engine mounts but most of it is ready. All that's left to do is fit the oil pump but I didn't receive it yet... have all the steel to make the bracket and all the aluminum tubing to plug it in si it should go pretty fast.

Trouble is that on my side of the equator winter is approaching fast. All hopes of having the engines in the car before the cold months have almost vanished. Sure thing is that it'll be ready when spring arrives. You see, I'm pretty busy and I'm building that thing part time. I also chose to not cut any corner at all on that build so it's a lot more time consuming that just slapping back an engine together... It's turning into a freaking long engine build I agree with that but by the time it'll be finished it should be close to perfect so I think that in the end it's worth it.

[Mjh]

Thanks
Yeah it will be worth it
Was keen to see results once finished as could have been a good option for Racecar engine build for me

But I'm patient and can wait a while longer

[bermy]

Well, more custom stuff on the way... decided to change the oil pump drive



Using a 3S-GTE timing belt along with the 7A gear set... and more custom toothed belt drive are probably coming on the water pump/alternator belt.

Stay tuned

[bermy]

Well it may be time for an update.

Decided to use carbs for simplicity and to keep it "period correct" with the KE20 chassis it's going in. I know a lot of you will disagree but I don't care lol



Changed all the drive belt setup :

2JZ belt using 7A crank gear and cam gears, stock cam centerline moved from 111/111° to 108/108... 3 degrees on each cam increasing overlap. Way better than then old porsche t-belt.



Just need a little modification :




And here's the final setup, now just need to plate the pulleys



Fitted a 5S-FE oil cooler (almost the same as 3S-GTE except fitting position) to get more constant oil temp and fewer oil pressure lines running around



Feeding cold water right out of the water pump



Deleted the pressure release valve in the external pump



And welded the stock outlet port



And will be using the M18 threaded port that normally has the cap for the pressure release valve spring as the new outlet.

This is how the pump will be mounted with the new outlet directed downward and the inlet to the back



I'll redo the bracket in thicker metal and will combine it with the engine mount as I need to make new ones. It'll be stronger that way.

[bermy]

Sealed the pump shaft



And both halves



Changed the oil setup. Decided to use the external pump as a scavenge stage in a drysump setup. It has over 3 times the displacement of the stock 4AG pump so underdriving it at 57% crank speed should be about perfect to pull oil out of the pan and some vaccum with it. Will use a standard redtop crank mounted pump as the pressure stage so the external pump and all 3 hose will be run at low pressure.

Speaking of the pan, here's what I did :








Had some help pulling the 7A pan on father's day


And mocked up the new pan before painting to see if all was perfect


Should get the remaining AN fitting tomorrow... will update then.

[.T.]

using the scraper as a dry sump pan was an interesting idea. flange will be a bit thin though!

[bermy]

Yeah, I cut the stock flange on a 4A-Fe pan and will bolt it on top of the pan so it'll be like stock and serve as a huge washer to distribute de load of the bolt... also got a bunch of 12.9 socket head screws that'll be safety wire to keep everything in place.

I can post additional pictures... got the thing painted and the engine is in pieces now having the crank assembly balanced.

[Esteban]

Any updates on this build?

[bermy]

Any updates on this build?

Lots and not that much... let me explain.

Got the engine finished... for the Xth amount of time







Clearance? lol



But then decided to go big or go home... got some used FA pistons, with the 19mm piston pin moved up...


Turns out they fit like gloves on later nissan rods : GA16DE and QG18DE rods (which are the same, 3mm longer than the E15ET rods but with a 19mm bushing for a floating pin) so require no modification although the block need to be decked by a couple mm to achieve perfect compression...

So got a set of those rod from a local scrap yard...



...and tore the whole engine apart... yeah... AGAIN!!!

And here comes the crappy part :

Split up with the mother of my son last march, sold her half of the house, bought an apartment... and was forced to sell the project car this engine was destined to to a friend of mine. I kept the engine and parts, invaded my father's garage with all my shit but was out of a car to set the engine into... and out of a place to work on a weekend car...

Anyway, fast forward 6 months... I finally traded my "hair dresser's" celica (my only car since the shit hit the fan) for something a bit cooler. Got my hands on a nice AE95 wagon... with a 4A-GZE... so I do have a car to set the engine in now... problem is that the AWD drivetrain really calls for the Z in the 4A-GZE... and with 13:1 compression, I can see trouble coming fast.

So I got my hands on a set or OEM forgies low comp AW11 pistons... which should find there way in the destroked 7A with the old modified E15ET rods already bushed for 20mm floatting pins... and a fresh new ported largeport head with FA size O/S valve... and some PDM 261 cams...

For those keeping count, yep, this is the 3rd set of pistons to find its way in... without ever firing the damn thing.

Anyway, since it is destined to live in my daily car, I will retro-fit the stock lubrification system (pan, pump, strainer, oil cooler, etc), the stock transverse mount cooling setup (pump, thermostat housing, plumbing) and will bolt up all the accesories from the GZE so no more toothed belt to recieve rocks and crap while I beat on it on a dirt road somewhere in the canadian wilderness lol

Will probably run the stock GZE ECU and stock size crank pulley has I have the intension of pulling more revs from it (kind of the reason to build a long rod engine in the first place) and don't want the SC12 to blow before I reach the redline... will probably end up bumping compression slightly to ccompensate for the stock boost levels.

So yeah, the little thing almost died without firing a single shot... but it should rise from the ashes