Roman's 4GR V6 Carina discussion thread

[dabuzz]

Wait, so you're not rebuilding the motor in the warmth of the lounge like any true petrol head would? 

[Roman]

Unfortunately being murdered by Steph doesn't align with my long term engine development goals.

 @440bbm I will pass on the lights but thanks for the offer. 
It's mainly space rather than lighting.
When it comes time to put lights in the new garage I'lll get LED setups again. Was awesome at the last place.

[xsspeed]

are you still doing the flat packed 2nd hand shed or getting all new?

[Roman]

Yeah, 2nd hand shed to put up. 

Probably cost $10k or $12k all up, compared to comparable quotes at $35k -40k for brand new.

The shed I had at Matamata, that we had built just prior to covid. Now costs double what it did to do the same again. 
 

[Hemi]

THis thread is incredible Dave .

im extremley interested in this whole 3d printing in metal thing. I legit just want to make a noodle man in paint and get it metal printed just because. how cool is technology!.

stink about your valves thouygh

[anglia4]

My experience of 3D printed metal parts has been good.

Where I used to work we made a machine that they had made heaps of, and it had one part in it that was die-cast stainless steel. The die had cost a fortune to make, and only made sense for the production numbers we were doing. Then of course some turkey of a salesman sold a machine that was a "custom" slightly different size kind of thing, and it needed a variation of this die-cast part to make it work. We had one printed in Stainless Steel and it worked perfectly. We were all very impressed.

[Rhyscar]

Interesting about the shape of the collector. Eager to see how it works out. You weren't keen to try a basic FEA simulation?

Have you seen this? Burns stainless have an adjustable collector you can buy to tune before settling on a solution. It may shed some light on different geometries. 

 

[anglia4]

2 hours ago, Rhyscar said:

Interesting about the shape of the collector. Eager to see how it works out. You weren't keen to try a basic FEA simulation?

 

I don’t think a basic simulation would yield much value for a merge collector. It would need to be a very dynamic sim to consider the effects of the pulsations, which are more than likely the more important factor.

[Roman]

Yeah the collector shape might suck.
However I'm not too worried, this isnt the going to be a car where it's just put together once and then that's that.
So I'm not fussed about getting everything perfect, just get it all to a functional baseline.
Then try out a whole bunch of different configurations of everything.

Like if I get a different style collector made, and it makes a really awesome difference (for better or worse) that would be awesome to see.

I'll do a 6-1 collector/manifolds as well to see if it makes cool F1 style noises.
Then there's so many other things I can play around with once I've got a bigger garage again and the car is running. 

Try different exhausts, different collectors, different manifolds, different intake lengths, and so on towards infinity.
Try a destroked 3 litre, different porting, and heaps of other stuff.

I might have major problems avoiding rockers flicking themselves out. Just dont know. But its all going to be good fun.

It would actually be kind of disappointing if it was within 95% of it's potential on first go. haha.

Just have to get to that point first, after sorting out all of this annoying stuff.
I've got the motor mostly back together now, but I've had some annoying holdups. 
Like a split O ring on the thermostat housing, and then one of the other O-rings swelled up from the degreaser I used, so have to get another one before I can put it together more. 

I am in super fizz mode to see how the metal 3d printed stuff turns out though! 
 

[shrike]

 

[shrike]

Keen to see how the rest of the exhaust comes out and great to see more progress

No chance of 3d printing a complete manifold? or is it silly costs?

Assuming you have done everything to prevent the cam failure from happening again now youve gone to the later model parts etc?

I really need to learn CAD, some of this stuff is super cool

[Roman]

Yeah definitely want to try print as little as possible to keep the costs down.
By which I mean, anything that is low mass and high complexity is worth printing. 
But you wouldnt bother printing a beefy flange or some straight pipes.
But combining printing the complex sections, with some milled flanges and regular straight sections and you could make something awesome that would go together easily (says me thats never done it)

My intake manifold is "okay" but wont last long term. 
So I'm thinking it would probably be a good scheme to mill a piece of 6mm alloy as a big flange on the bottom, then have 6x 3d printed parts with the complex shape that slot into it.

 

[VitesseEFI]

That 3D printed collector looks great. It’s witchcraft, but great. Especially interesting to me as I could do with something similar to replace the butchered remnants of the 3-1 section of the 6-3-1 on my Vitesse.

I have a question though. How are you planning to seal the centre section where the tubes come together and meet the collector? Doesn’t look like there’s room to get the welder in once the tubes are in place….. I guess you can TIG the tubes together in the centre so they are sealed there, but only around the outside to the collector itself.  Not sure this gives a total seal but maybe enough….?

[anglia4]

It might almost be worth cutting it so that you can seal weld the inside of the tubes, and then weld the collector back together again. Then you can weld the outside of the tubes to give it strength, and not have to worry so much about getting down between them.

[Roman]

The idea from the start has been to weld the three tubes together on the inside first, before they slot into the collector.
Then the only weld to the collector happens around the outside.

That's the plan at least...

Also, the alloy bits turned up and they look cool as well. 
Not quite as nice as stainless.
But to be fair I threw what has to be a worst case scenario at them, with lots of small fiddly details.

[HighLUX]

I love the detail and full use of available tech/processes that go into romandave builds plus having driven a bloated whale of a mark x for the last few weeks I can appreciate that that a 4GR with all its potential unlocked will be nothing but great in a small 80s toyota

[shrike]

Haven't done tig in ages (Highschool ish) and don't own a machine currently (My unimig does scratch start which I am hopeless at so don't even attempt) and my mig skills aren't amazing (look at my fake evo thread ha)

But you are doing amazing and are definitely getting better with practice, like a lot of us here a grinder and paint make us the welders we aint. Even with stainless heat coating or wrapping hides alot and if it penetrates and doesn't leak thats a win in my book :p

Nothing wrong with function over form

Might be worth a brain storm with people that commented about your collector design in this thread before you send the next file off to be made, just to see if there is any other ideas to make your life easier

Loving the progress, and im frothing with you for this thing to be doing stationary cooling tests

Anglia4 did suggest cutting it to make welding easier as well

Could always make it a interference press fit :p assuming they expand in the same rate when heated haha (im joking)

[yoeddynz]

My welding on my headers is not very flash either. Definitely not instagram worthy etc etc but really all I want it for the hot stuff to exit out the back and the whole lot not fall apart. Tig certainly is just practice practice practice however some folk just have a natural talent and seem to find it much easier to learn.

I'm not one of those people but I'm getting better.

The most important things I have found so far are..

-Good eyesight/glasses or cheater lens. Its no good attempting fine small welds when you cant see up close. I struggle more than most because I only have one working eye so I find it hard to judge distances and will often make my tungsten go for a swim. Not much I can do about that.. I just have to accept it. But yeah - good glasses if you're long sighted or a cheater lens.

-Stick a little led head torch on your helmet. Fuck it makes a big difference being able to see clearly the area before you start welding. Especially helpful if tig welding in awkward areas where there's shit light. I think it also helps with the sudden change in contrast to bright light from the torch once welding.

-Relax and be as comfortable as you can before you start to weld.

-Have about 4 or 5 big glasses of rum or whiskey before welding.

That last one might not help your welding but at least you'll be drunk enough to not really care.

 

[HighLUX]

Id agree with @yoeddynz welding is alot like playing pool, a few beverages or powerade bottles of smoke and your in the zone and can lay welds down that look great with all the penetration/lol penetration

[HumberSS]

+1 for yoeddys head torch trick. I wish my helmet had one built in!!