swedepat

Not much... the vacuumsource is still connected to the intakeflaps, they still work.
But theyŽll probably have more unstable function as when opening throttle there is less vacuum to control them.

swedepat

Tell me more i already know
Never had the use for any flowbench, still ported heads that has taken inofficial records(at the time) and those old heads still hang with the best in Sweden.
As i often mention: Those who need a flowbench donŽt know how to port!
Yes they might succeed but they still had to use a tool to get things correct.
And i have always had success having as free flow as possible into the plenum, here there isnŽt any demand for high speed of air(slow moving air has higher density than fast moving)
Down in the inlet runners(in the head) the shape is very very important to maintain high flow AND high airspeedthrough the chokepoint, this to fill the cylinders as effective as possible and get no reversion before inletvalve closes.

yada yada yada, one can write a wall of text in this topic but no idea as you already should know this

I can get back with results in A-B-A test, but it will be in ~may 2022 as i have put my merc into winterhibernation.

VektorPerforman

Totally understand if you're doing the same thing every day and have a proven recipe.

In an R&D environment that is constantly involved with new development; where you need to know where you're starting and what gains made at certain flow, velocity, pressures, etc., it's a great tool.

I don't like to classify myself as an old-timer. I prefer 'experienced' That knowledge is great to have, but using technology is a worthwhile advantage.

Looking forward to it! Are you able to log or plot MAF, IAT, and MAP as well?

swedepat

I have through the years applied small changes all the time, and at the same time asked customers if they allowed me to do it.
There have never been any step backwards.
But they were always tested in my own racing engines.

And i understand it, i have been fighting this in Sweden many many years, some people just donŽt have the gift and need to learn.
IŽm actually 'fighting' this war again with towstrokes, as a reborn hobby of mine.
Without a big team of developers iŽve got more power in my yamaha TZR250 than the factoryteams got from theis racing engines.
LetŽs say it like this: iŽm 50years old now, and started tuning my twostrokes when i was 12years old.
My first 4stroke was when i was 16years old.

One could almost say that: all the water in the world has flowed through my creek

swedepat

Offtopic..
But as i have decided to go 82mm throttlebodies i started to study why is it a gain, two 74mm bodies should have way enough flow for 600+hp
Investigated a bit and i can see that when flow enters the plenum after the throttlebodies it is way to crammed for the air to evenly fill the plenum at high rpms AND where airdemand is largest per enginecycle(torque peak)
An idea i came up with is to somehow space down the 'lid' that the bodies are mounted on and at the same time space the bottom of the inlet down towards the engine valley.
To make room for this one have to space whole inlet manifold upwards the same amount.

The 82mm bodies simply allows more air to sneak past the flaps and fill plenum more efficient.
IŽll check this up further as i go, a 10-15mm spacer would do much for flow into the plenum.

AMGonFire

on topic lol did your engine start back up fixed?

swedepat

Not yet,, I'm doing this 82mm mod first.

djr48312

Headbolts if it's pre 2011?

swedepat

ItŽs already done, itŽs an early 2011.
Owner before me changed them.
Lifters and camshaft looking top notch.
Campulleys are new ones.

swedepat

HereŽs why it takes some time, i have printed different designed velocitystacks to see what can make room with my other ideas.
This is the final design(i think) Throttlebody number two is on its way home as we speak, canŽt make final decision until i have them both.
When i have decided i will cnc them in aluminium.
The PLA i use for test canŽt take the heat inside the plenum.

These have a low profile to make room for air easily being drawn into.(lower than stock stacks)
I have cfdŽd them in cad program(fusion 360) and they seem to work just fine.

swedepat

And this is how 'off' the new boltpattern is.
But i have a solution even for this, it includes NOT drilling new holes into the plate they are mounted on and having bad vacuum leaks.

I noticed a thing also, when unbolting the throttlebodies from the oem plate, the plate actually distorted a little so when putting the throttlebodies on again without bolting them down, they 'wiggle' a little, also a potencial problem for leaks if not beeing able to bolt the new throttlebodies down securely.

swedepat

This is the outcome.
Just heat them up and drop them onto the bodies.

swedepat

I also got pmŽs about asking if i could do more velocitystacks, but i cannot make more than my own needs.
But you can have the 'blueprint', iŽm not greedy.
If a company like VRP or something makes a ripoff, itŽs a confirmation for me doing good stuff.
Just send me some merch and iŽll be happy
All measurments in metric system.

YvngGold

Honestly i feel like i got so lucky. Had a stuck injector and my engine was stumbling. Luckily the starter case broke and got stuck in the fly wheel not allowing it to spin or else it would've been a big hole in my pocket :,(.

swedepat

If the god are with me my case is cheaper, so far i have just bought new injectors to adress the problem.(my starter is fine)
But as i put my amg to winterhibernation i started modify stuff also

swedepat

Been designing(not finished yet) adapters to fit 82mm bodies on std plate.
You can see result later when iŽm done.

I will add o-rings for sealing and some m6 studs and m5 threads.

sventastic82

Your starter broke because it could not turn over the engine due to a fuel filled cylinder.

swedepat

Wanted!
Oem inletmanifold M156, can be damaged as long as the bottomplate is fine.

swedepat

As plate with bodies is done iŽm now going to look at that spacer i was talking about earlier to get more room inside plenum.(thereby my 'wanted' post above)

swedepat

done!

A little bit of portwork to try to diffuse the flow into the plenum, better possibilities for filling the plenum better.

One of the adapterplates, they are o-ringed on both sides.

I have been trying to make sure everything is backed up with some sort of locking method so nothing will came loose.
Loctite strong and jamnuts, securewire etc etc..
and i also used loctite 5910 to ensure seal even more when i bolted it together, i will NOT have any sort of airleaks as i read other guys had.

Now onto the spacer, i need to cad for a while before i have anything to show.

swedepat

Stop screws,


Even thou the stacks are shrinked on onto the bodies i used loctite bushing mount glue and lockingscrews.

swedepat

Due to complexity of the shape of the oem spacer in the inlet manifold, i am in no longer search for a manifold.

But some new ideas are taking shape, but it will be a long time project.
I need to do some research first.

However, engine is probably going back together this weekend.

swedepat

Starting went smooth.

AMGonFire

👍🏻

swedepat

A hot tip!
when bolting down the inletmanifold, junk those oem m8 aluminiumbolts, do not buy new, exchange them for real 8.8 bolts in steel.
This way you can get rid of small leaks.

I noticed when i took mine apart that the inletgaskets had moisture all the way through the whole sealing surface, as if the inlet wasnŽt properly clamped.
With steelbolt you can torque it down more to get more clamp and by that more press on the sealantmaterial on the gaskets.