Roman's 4GR V6 Carina discussion thread

[mjrstar]

If they are milled to the correct pcd not wildly oversized and there is still a good land for the bolt head I don't see too much of an issue. 

Welding the chromoly then remachining for trueness opens up some potential headache in my opinion.

[Roman]

Yeah welding it isnt even really an option, because it's super thick there. As this replaces a dual mass flywheel.



But that's also what gives me some confidence that it's not going to blow to smithereens either.
Alternatively I could drill new holes in between centers of existing, but I think slotting would likely be the better option.
The consensus of internet facts(tm) seems to be that so long as you're slotting outwards rather than inwards, it's okay. 


 @shrike I think the radiator will be fine, will just mix and match hoses to make it work.

[mjrstar]

You won't need to do that anyway because we know you are putting an 8 speed dct and paddle shift in it like all the cool kids have been doing for a while now..

https://www.domi-works.com/collections/dct-adapter-kits

[flyingbrick]

2 hours ago, shrike said:

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

Sad that I have been beaten to it, but yeah. The bolts provide a clamping force regardless of if slotted. The spigot in the center needs to remain a circle though (lol)

and yes, no to welding as the HAZ could be more detrimental to structure than any slotting.

 

[HumberSS]

Are you planning on casting the manifolds or printing in something spesh?

[Roman]

I will do the same trick as before, print with Nylon PA12 and then wrap with carbon fiber. 

This time I'll add some crush tubes so the bolts can do up tight without having to be precious about overt tightening them.

[flyingbrick]

9 hours ago, Roman said:

I will do the same trick as before, print with Nylon PA12 and then wrap with carbon fiber. 

This time I'll add some crush tubes so the bolts can do up tight without having to be precious about overt tightening them.

I watch a lot of boat building videos on youtube. no idea why. Anyway, they often drill through fibreglass and foam to mount things to the deck- and they need to protect the raw edge within this hole from water. To do this, they drill the hole oversize, fill with epoxy resin, then drill their final hole down the centre. Basically, there is a "crush tube" of resin formed. 

As resin has a relatively high compressive strength- maybe this could work and be easier than a crush tube 

 

[yoeddynz]

On 24/02/2023 at 07:21, 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

Video of Dave dropping a V6 onto scanner please 

[anglia4]

Does the clutch sensor need to be analogue?

[Leone]

It’s prolly been answered (lazy) but what is the length of the block?

[Roman]

I'm not too sure, but I'll measure it when next in the garage. 
However I can confirm that it's bloody huge.

 @anglia4 my ECU actually only accepts a digital input for "clutch", so I'm actually using a general purpose output that then triggers a virtual on/off switch. 

Reason for doing it this way, is that matching the on/off switch to the clutch engagement point for rev matching or flat shift is super critical. 
So being able to adjust in software is super awesome.

It's not strictly necessarily but it's an absolute life saver. 
I can add other analog or digital stuff over canbus as well, so not hugely stressed about running out of IO. It's mainly just a case of making sure that all of the mission critical stuff is direct to ECU where possible.

[keltik]

I think one of those bmw things runs an external e-throttle actuator with a linkage up to the actual throttle bodies.

I think they also explode a lot.

Carry on

[anglia4]

Yeah linkages!

 

[Roman]

Ahh look at that luxuriously spacious 90 degree Vee! 
60 deg vee makes life a bit more tricky for the intake. But, it also gives better room for the exhausts which is sorely needed. 
Win some lose some. 
It would be nice to be able to cross the runners across the vee like that V8.
But that only works if your throttles are spaced apart at least as far as the ports. Where as my throttles are closer together than the ports. 
The other pair of throttles turned up today, as well as the H bridge controllers.

Looks like I'll have way more room than expected if I want to make them more vertical or push them closer together.




I'm desperately trying to avoid raising the motor any more, so the sump situation is taking a fair bit of trial and error. 
However I've got a setup that now clears the front pulley, the pan nearly fits okay (will push it back a bit further from the swaybar)
Then still dipstick hole and oil filter to figure out. 

 

 

 

[flyingbrick]

Could you turn each row of throttles 180 so that the servo hangs off the other side- then stand them up more vertical so that the air doesn't have to do such a sharp turn after the throttle?

Or, could you do a one piece lower manifold that manages the cross over, then mount the throttles basically flat as soon as they have finished crossing over?

edit:
You appear to be moving too quickly on this, so i'd like to add more complexity. Thanks.

[Roman]

I cant flip them the other way because the fuel hose connection onto the fuel rails will hit the bonnet.

The problem with standing them up too much more is that it limits me to something like a 20-30mm trumpet on the end. 
Not sure if that will be enough runner length. Although, the head does have quite a deep port.

Key thing here is to try keep making progress towards getting a running motor. Then play around with all the variations on things for about 55 pages later on. 

 

[yoeddynz]

On 07/03/2023 at 11:43, Roman said:

I cant flip them the other way because the fuel hose connection onto the fuel rails will hit the bonnet

No probs. I've got the solution for you! 

 

[flyingbrick]

I would like to see the centre of the bonnet cut out. Six trumpets poking out would be awesome!

[ajg193]

I keep forgetting that this isn't going in to the Echo...

[xsspeed]

hey dave whats your estimate on weight diff between the 3s and this? I thought you had said something like 50kg but wondered if youd started weighing anything?