Tech Spam thread - because 1/4" BSP gets 5 hand spans to the jiggawatt

[yoeddynz]

On 31/03/2024 at 20:30, NickJ said:

Also those are very nifty relays that I really should have on a few cars.... But I won't actually be needing because I'm going to put efi on everything and live like a boss. 

 

[yoeddynz]

This engine here... 

Which I think might be a Covair air cooled flat six ( @NickJ dad can confirm)

If so then how would that work properly with 4 carbs?  Like how is the mixture evenly distributed? 

[tortron]

One dummy carb on each side. It's a street rod m9

[yoeddynz]

Some fella from the group commented on the photo and said two carbs are for primary fueling, the others for secondary.

Seems a bit complex? 

[Nominal]

Might be on a progressive linkage?

[Nominal]

Same setup as a Holden twin carb I suppose

[yoeddynz]

That just makes my brain hurt. 

[GregT]

It's not optimum - but it does work.  The flat 6 won't have a lot of overlapping vacuum so distribution should be good enough. From experience with a 36/36 Weber on a hot 202, the volume of the main log of the manifold is fairly critical. Too small and the ends starve. Too big and response goes away.

[NickJ]

6 hours ago, yoeddynz said:

codswallop 

Sorry sun, ol mate Skinner has me sorted

[yoeddynz]

1 hour ago, NickJ said:

Sorry sun, ol mate Skinner has me sorted

just make sure you fill the dashpots with ep90 for max fuel on acel

[JustHarry]

On 10/04/2024 at 15:54, yoeddynz said:

Some fella from the group commented on the photo and said two carbs are for primary fueling, the others for secondary.

Seems a bit complex? 

No worse than pontiac tri-power.

 

[h4nd]

https://xkcd.com/2916/

 

[gibbon]

quick question, are the rod and head bolts on the old 4G63 reusable or one and done? @fuel @bigfoot

[bigfoot]

23 minutes ago, gibbon said:

quick question, are the rod and head bolts on the old 4G63 reusable or one and done? @fuel @bigfoot

Quick look through my workshop manual doesn't say to replace them

[gibbon]

hmm I've found a manual too and it doesn't say replace, but the torque figure is 20NM plus 180 degrees, isn't that a hallmark of torque to yield bolts?

[gibbon]

stuff it, a whole replacement set is like 80 bucks lol. cheap insurance

edit: $40 bucks through Segedins

[fuel]

depends on the age I guess - the older 6 bolt 4G63s had reusable hardware but the modern stuff (ie Evo 4 style onwards) tends to be TTY

[bigfoot]

Mine says head 95nm

Rods 52nm

As @fuel said, you may have a late model manual

[gibbon]

ah, I think I probably do... I just saw "sohc 4g63" and figured it was the old model but of course they probably kept building them forever. 

Oh well now i have a set of new TTY bolts on the way, I suppose I'll use them - the engine was rebuilt not that long ago, can't be sure that the head bolts that went in at that time weren't TTY too 

[igor]

Is there any engineering benefit to the use of TTY bolts?