Jump to content

Roman's 4GR V6 Carina discussion thread


Roman

Recommended Posts

I don't actually know but if I was speculating the sump on these modern motors is probably factored into the block rigidity equation when they model/test/create these modern alloy engine blocks. Usually they tie into the gearbox etc so they are a structural part that probably adds rigidity to the bottom end. In motors that have shitty bottom ends (old shit with average designs) block rigidity problems usually show up when you rev them more than stock and the block/crank gets wobbly and you run bearings more often or get funky harmonics. I would guess that is why that guy with the turbo motor in the 86 made a custom sump out of a chunk of alloy so its as strong or better than the original part. This is just me talking shit as I don't know if it was designed to be structural or not, something to consider when replacing it though.

  • Like 1
Link to comment
Share on other sites

  • Replies 652
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

5 hours ago, Spencer said:

I don't actually know but if I was speculating the sump on these modern motors is probably factored into the block rigidity equation when they model/test/create these modern alloy engine blocks. Usually they tie into the gearbox etc so they are a structural part that probably adds rigidity to the bottom end. In motors that have shitty bottom ends (old shit with average designs) block rigidity problems usually show up when you rev them more than stock and the block/crank gets wobbly and you run bearings more often or get funky harmonics. I would guess that is why that guy with the turbo motor in the 86 made a custom sump out of a chunk of alloy so its as strong or better than the original part. This is just me talking shit as I don't know if it was designed to be structural or not, something to consider when replacing it though.

 

Everything I've read about the 1gr indicates the upper sump ads structural rigidity to the the block. 

Link to comment
Share on other sites

Quote


Cool vid @Roman

Im nub as, did that program pick up the ports and bolt holes and you just put in the measurements?
if so , that made me a whole lot more excited about trying stuff


Usually I'd rather just draw things starting from measurements and dimensions, but this was an exceptionally good image to start from. 
Then I drew the bolt holes and port sizes on the 2D image.
The reason I left this part out, is that there's not much magic going on with this stuff, and you'll need a good handle on drawing 2D images first, and plenty of tutorials etc. 
Just mainly wanted to show how to generate the geometry between two planes/sketches in a way that has nice cross sectional area and change of shape. 
 



Hey @Hemi,
It doesnt do that stuff automatically. 
What I did prior to the start of that video, is that I found an image that was nice and "flat" as in, had minimal perspective distortion. 
If you are standing really close to something when you take a photo, the center part of the image is closer to the camera than the edges, and you're viewing everything less parallel.
So you get distortion of sizes.
Fish eye lense is an extreme example. 
If you stand further back and zoom in, then you get everything propertioned more correctly as this effect is minimized. 
So, thanks to the random internet photographer person who took those nice photos of a 4GR block, I had a good image to work from.
So once you've got a nice photo, you need to import it into the program and then tell it how big it is. 
So normally you pick between two known points, and enter a dimension - then it will rescale the image to that distance. 

  • Like 5
Link to comment
Share on other sites

4 hours ago, Roman said:

 



Hey @Hemi,
It doesnt do that stuff automatically. 
What I did prior to the start of that video, is that I found an image that was nice and "flat" as in, had minimal perspective distortion. 
If you are standing really close to something when you take a photo, the item at the center of the photo is closer to the camera than the items at the edges, so you get distortion of sizes. 
If you stand further back and zoom in, then you get everything propertioned more correctly as this effect is minimized. 
So, thanks to the random internet photographer person who took those nice photos of a 4GR block haha. 
So once you've got a nice photo, you need to import it into the program and then tell it how big it is. 
So normally you pick between two known points, and enter a dimension - then it will rescale the image to that distance. 

Ok cool, so im nub as.
wh9ch is cool, because yeah.

  • Like 1
Link to comment
Share on other sites

I quite often drop oily engine parts directly onto the glass of my A3 printer/scanner, with a 300mm ruler laying beside it.

You can then import the scan, draw a 300mm line, scale and rotate to suit, then you are away.

I have done the pic method a few times as well, its just not quite as accurate.

  • Like 7
  • Thanks 1
Link to comment
Share on other sites

2 hours ago, ThePog said:

I quite often drop oily engine parts directly onto the glass of my A3 printer/scanner, with a 300mm ruler laying beside it.

You can then import the scan, draw a 300mm line, scale and rotate to suit, then you are away.

I have done the pic method a few times as well, its just not quite as accurate.

this is exactly what I do. That or a photo with a ruler. 

I also utilize works printer for getting scaling etc right. Most printers seem to be extremely accurate when printing things 1:1 scale, and they can do it in a few seconds, so with this sump flange I'd just have printed it out and put on top of the sump to check.

@Roman since we are going to be neighbors soon- more than happy to use works printer and bring you home stuff if needed, we even have a3 paper.

  • Like 1
  • Thanks 1
Link to comment
Share on other sites

So I'm still tipping 200kw+ not sure what the factory rods are like, but not sure if they will do 10k rpm guess it depends how heavy they are and how well its balanced from factory

I am assuming you'll do valve springs as a minimum and be going for custom exhaust/headers might even crack 220kw atw (would love if it got more however :p)

Whats the harmonic balancer/engine dampener weigh? and are you going to run many auxiliaries on the motor?

I've been having a play with the Automation game and well some of the figures aren't super realistic it can be an ok guide/indication sometimes

Couldn't get down to 83mm bore (84.4mm smallest I could go) but with cast rods/pistons it was happy with 8400rpm, would say 9k with the smaller bore is reasonable

ITBs, exhaust etc (with springs) it did 270kw at 10k rpm lol which Im not sure about, might upload something later if you want a laugh?

4GR map.png

4GR.png

  • Like 3
Link to comment
Share on other sites

On 23/02/2023 at 22:28, Roman said:

Also, something has been boggling my mind a bit. 
Lets say you have two 2500cc engines, one is 4cyl and one is 6 cyl. 
Lets say they are both doing 6000rpm and both have 100% VE at full throttle. 
Does the v6 make more power because its breathing more air in, because its got more cyls and more valves?
No, because they have exactly the same amount of airflow going into the engine.
As displacement is the same and VE is the same. The V6 just cuts the pie into more slices.

So what's the point then?
Well, hopefully with a V6 at high rpm the VE number can stay higher as rpm goes up, as there's more valve area.
So for example a K24 motor has a 36mm valve with a 5mm stem, a total valve area of 7984mm2 with its 8 intake valves.
A 4GR has only a 32mm intake valve, and assuming 5mm stem as well. On total area it wins by 17% with a total valve area of 9408mm2 with its 12 intake valves.
So hopefully the idea is that when the 4 cyl motor's valve area starts becoming insufficient towards higher rpm and VE drops off, the V6 still has enough valve area to keep flowing well.

I'm really pinning all my hopes and dreams on this motors ability to rev really high, as it's the only real upside to this big chonka.
It's still possible that there's some fundamental reason why it wont be able to.
Like maybe the crank will break or the oil pump will explode or whatever.
Also, I am very cautiously making comparisons to a K24 because it's unlikely that it will make power as good as a K motor setup will. 
But, forgetting the power figure. What if it does rev well and everything's okay, and its absolutely massively awesome? How good!
That daydream is alluring haha.
 

Would the increased VE be offset by more friction/weight slinging extra pistons and valves etc around ?

  • Like 1
Link to comment
Share on other sites

I'd be hesitant to slot flywheel bolt holes, could probably get them welded up and then redrilled though.

How much shorter does the rad need to be for the hoses to line up? Could be worth seeing what other models may fit

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...