High compression high RPM 7M-GE build

[andrew_mx83]

I got your retaining plate/bearing today. This thing is pretty sweet. Great work! Thanks!

Hey mate glad you like it!

Not much progress on the engine, my father is pretty sick atm so car stuff is on the back burner a bit as im spending most of my days at the hospital and trying to keep up with work in between.
I made a bunch of valve shims this week but havent got them finished yet...
still waiting on f*cking pistons anyway, this is getting ridiculous
there was a small delivery of fittings this week so i can get stuck into the oil pump outlet when i get a spare minute

thats about all there is to report at this stage, hopefully real progress can resume soon.

 

[andrew_mx83]

ok so we all know the stock oil pump outlet pipe is shit and ive run the hard line on many motors now but i always thought there was room for improvement.
in particular i wanted to bypass the restrictive gallery in the block which runs vertically between the hard line and the oil filter, and generally gain a bit more flow.
so i made up a billet steel fitting for the outlet of the pump which allows me to take oil directly out of the pan, bypassing said small gallery and bumping the hose size up to -12AN. this was just a trial piece, revision A if you like. there will be a couple of small changes on the proper one.

pump outlet drilled and retapped M20 to fit the bigger pipe ID i wanted to run

install fitting into pump, install pump in block and fit oil pan

then screw the AN fitting in through a pre-drilled hole in the pan, sandwiching it between the 2 fittings. the pan will then act as the sealing washer you would otherwise use on a parallel thread pressure fitting such as these. (i still need a locknut and washer for the pump thread.)

(imagine there is an oil pan fitted here)

ok now we have bulk oil coming directly out of a fitting in the pan, it then goes via a -12 braided line to be filtered and cooled...

...then bought back into the block, straight at the main oil gallery to feed the bearings.

 

[andrew_mx83]

so why go to all this bother? lets have a look at the math....

stock outlet pipe

not much bigger coming back out of the filter and into the main gallery

and lets not forget the vertical gallery in the block, which is around 12.5mm


this is looking a bit better

still a bit small through the fitting into that vertical gallery

uh-oh!

now, thats more like it!

some rough numbers on cross sectional area:
11mm inside dia = 5.5*5.5*3.14 = 95mm^2
16mm inside dia = 8*8*3.14 = 201mm^2

should give a pretty hefty increase in flow.

 

[andrew_mx83]

please note the above posts are not intended to be dissing any competitor's products or anything, im simply trying to show why ive done what ive done with all this. if they are inappropriate please let me know and i will edit them.

 

[Grandavi]

Truth should never be edited.

My brain is asking, for normal application (considering the Toyota engineering dept), this would help but is a lot of work for little gain?
For your application it would be totally necessary or you would risk too high pressure (too little flow) at the higher RPM. (If I understand everything so far)

Really interested in two things watching what your doing... Longevity and performance.

 

[Backlash2032]

Just curious how this is going to effect pressure at low rpms..

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[NegativeGeForce]

That's a slick mod. Its overkill but If anything its a cleaner way to run your oil cooler setup by having one line on each side of the motor vs two by the already cramped hot side.

There really isn't a problem with the stock oil system on the 7m. It's just that it doesn't tolerate low oil. I'm using the Arizona pipe and an 8qrt pan with trap doors...that's plenty for 1000hp and 9k revs...just gotta make sure you got oil always feeding that pickup.

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[TurboStreetCar]

Wow, never saw this untill now. Awesome work!

 

[SeeUSmile]

loving the innovativeness andrew!

 

[andrew_mx83]

Truth should never be edited.

My brain is asking, for normal application (considering the Toyota engineering dept), this would help but is a lot of work for little gain?
For your application it would be totally necessary or you would risk too high pressure (too little flow) at the higher RPM. (If I understand everything so far)

Really interested in two things watching what your doing... Longevity and performance.

Really just not needed for mass market applications, cost/benefit ratio vs target market and all that. external oil lines mean more work for installing in the car and also there is a greater chance for leaks (like the 7m needs more excuses to leak!)
too much pressure is sorted by the pressure relief valve, this is all about adding flow. basically within reason you cant have too much oil flow (as long as you can drain it back). especially at high rpm when the b/e's are working VERY hard as the piston changes direction at 5000ft/sec. cbf doing the math on G force, but it will be a fair bit. the more oil you can force through those bearings under these conditions the better.

Just curious how this is going to effect pressure at low rpms..

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hopefully it wont. if anything it will take a bit longer to initially build up pressure. however if it is an issue i will just add either a fixed or variable restrictor in the outlet line until i get the low speed pressure back. ill be pissed if this is the case as it would mean i didnt have to retap the pump outlet to M20 to get the bigger ID in the fitting and could have just left it stock.

There really isn't a problem with the stock oil system on the 7m. It's just that it doesn't tolerate low oil. I'm using the Arizona pipe and an 8qrt pan with trap doors...that's plenty for 1000hp and 9k revs...just gotta make sure you got oil always feeding that pickup.

id have to disagree with you there sorry. once the HG is sorted the only real failures ive had from the 7m have been oil related. specifically chewing out b/e bearings. needs MOAR FLOW! if i can feed enough oil to the bearings and keep it at the right temperature it should just keep revvvvvvvvviing

That's a slick mod. Its overkill but If anything its a cleaner way to run your oil cooler setup by having one line on each side of the motor vs two by the already cramped hot side.

what is this cramped hotside you speak of? with no turbo the hotside of the engine is so easy to work on. plus i have no dizzy now which makes it even easier again. i removed the head from a Turbo A mkiii once, what a prick of a job. took hours just to get the bloody exhaust manifold off! N/A ftw!!
in contrast i can remove the head from a fully assembled 7m-ge in the car in under half an hour.... so easy you can do it on the side of the road in the middle of nowhere

 

[andrew_mx83]

well my replacement pistons finally turned up today. i havent measured them yet but by eye it looks like these ones might actually work.
spot the difference -incorrect piston on the left and (hopefully) correct piston on the right

hopefully i will get some time later in the week to mock up for clearance to the valves and confirm if i can get away with the 1.2mm head gasket.
the flat top pistons and 0.080" shaved off the head means things are all VERY close to hitting, but it also gives a hell of a lot of compression

if i can keep the 1.2mm gasket then i should end up at around 14:1 static CR...... should be good fun!

 

[NegativeGeForce]

Nice. Are those assymetrical pistons ? Looks like the old one has larger valve pockets..probably working against your insane desired cr.

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[andrew_mx83]

Pistons are CP, i dont think they do assymetrical ones. i think thats just JE?
valve pockets are the same size on both sets... the problem was a bit more dire than that, and i wouldnt have minded a bit more valve clearance anyway. those pistons wouldnt have worked at all in this engine, and probably not on a less modified one either.

problem was the placement of the pockets... they were spaced at 34mm when 7m valve spacing is at 36mm. because all my valve shit is so close to everything, this was no good. CP were great about it all and remade me a new set with no fuss. valve spacing is now spot on at 36mm


so i got ready to (once again) mock up for piston to valve clearance, and i took a couple of pics this time

prepare the head with 1 cyl worth of valves and set lash somewhere in the ballpark of right

install piston and rod into #1. got sick of shitty piston ring compressors so made my own for this engine. the tapered lead works really well, you center it over the bore and just drop the piston in! 1 tiny tap by hand it and falls all the way home. i LOVE this thing! makes life so much easier!

install used 1.2mm MHG and setup timing. i left the cam gears loose to begin with to give some more breathing room in case things wanted to lock up

whirl it around a few times, nothing hits, lock up the cam gears, still all good, it doesnt stop and i dont feel any resistance apart from the valve springs.


take it all apart, thinking all might be good and i can finally put the bloody thing together.

SO. FUCKING. CLOSE.
valve just kisesd the ceramic coating and took a bit off (not thrilled about this) but never actually hit the aluminium of the piston.


havent decided which way to go from here. i guess my options are:
get a 2mm HG and drop down to more like 13:1CR, pretty sure this will give heaps of clearance
make a fixture for the CNC and cut the valve reliefs a bit wider, then probably have to recoat piston crowns
machine the OD of the valves down a bit and add a mad chamfer
start from scratch on a new head and mill less off it (hell of a lot of work)
any other ideas??? intake valves already have to get cut a bit deeper into the head but it wont be enough to give sufficient clearance once everything is at temperature.

so frustrating!

 

[NegativeGeForce]

Id say screw it and put it together. Even if your tbelt busted somehow the chance the valve stopped exactly full open is almost nil. Nobody ever builds a race car for a rare corner case like that anyways cuz if your tbelt broke you have other problems imo. I clayed with a 1.4mm gasket and my intake valves cleared by a hair and exhaust valves hit the bottom of the valve pockets on my je pistons. I'm gonna use an hks 2mm stopper so it will be close but its not worth doing more milling. I'm putting it together and using a gates racing tbelt and clear timing cover and just monitor the belt.

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[IJ.]

Id say screw it and put it together. Even if your tbelt busted somehow the chance the valve stopped exactly full open is almost nil. Nobody ever builds a race car for a rare corner case like that anyways cuz if your tbelt broke you have other problems imo. I clayed with a 1.4mm gasket and my intake valves cleared by a hair and exhaust valves hit the bottom of the valve pockets on my je pistons. I'm gonna use an hks 2mm stopper so it will be close but its not worth doing more milling. I'm putting it together and using a gates racing tbelt and clear timing cover and just monitor the belt.

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Worst advice ever... :nono:

and you're building a 1000hp 7M??

 

[NegativeGeForce]

Yes I'm building a 1000whp 7m and it's not bad advise...it's just my opinion. The fact I don't feel it's worth it to take everything apart again just so I can have a non interference motor isn't worth it to me and it has nothing to do with making 1000hp.

You have to realize most race engines are Interference. They run way too much cam and piston volume to get every last bit out of the motor.

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[Rollus]

Andrew, I made a spreadsheet studying dozen of gasket thickness cases for my build.
Lots of formulas so easily customisable.
If you're interested, let me translate it in English and put some comments on how to use.
I'm going to share it online.

Edit: Here it is:
https://docs.google.com/spreadsheets/d/1Lxb9yWrr9BSezl07qeufFrzuL1INSTRrNN-tJ1HvaJQ/edit?usp=sharing

 

[Rollus]

Ho, and I'm building an interference engine with 256°/10.88mm advertised lift.
I have to clay it.
Be also aware that rods and valves may stretch a bit

 

[IJ.]

Interference means if a belt breaks a valve hits a piston, NOT that the relief is the wrong size,placement to begin with, get a clue before you start giving your sage advice...

 

[SeeUSmile]

looking good over there! shame to hear about the valve clearance issue.

I reckon your best bet is to machine the valve reliefs like you said if you wanna stick with the 1.2mm.