Sirius DOHC

[A112H]

Were any of these engines ever used in a rwd application?
I am pretty sure I know the answer but it doen't hurt to ask, what I am looking for is an easy out for the extractors, lol

[Benharjon]

HAHA good luck with that one jase! i am pretty sure there is nothing DOHC in the sirius family that was rwd... Best bet if they are the same exhaust flange is an l200 (early 80s?) They had the SOHC here (you may be lucky that these come out DOHC in the US but i doubt it!).

You may have to go full custom made or look at modding somthing from a galant GSR or Lancer GSR fwd? at least for the flange and then just mod the primaries...

Either way good luck!

[A112H]

I like your thinking Ben, I have this on watch, think it could be a cheap starting point
http://www.ebay.com.au/itm/STAINLESS-RA ... 27c9a7c89e

[Benharjon]

Could be a good base! cut it at the collector and go 4-2-1... being fwd orientated should help for a tighter bay, and allow you to route the 2 collectors and primaries where you like! Also looks awesome in stainless

Great work

[simon]

Hi,
I have just picked up three magnas - a TR, a TS and 1996 TE or TF? with 4G64 16v motor. I am not sure yet, however it looks like the exhaust flange could be the same as a DOHC flange. I haven't seen them side by side to check it out completely yet. The primaries are only 1 1/2 ", but you might be able to make more use of the secondaries. I am hoping to do something like this in my LA lancer.

Simon

[A112H]

Pretty sure the sohc heads have a large space between ports 2 and 3 where the dohc heads are evenly spaced between all ports. I think 84GKSIG has both manifold and should be able to confirm

[BlueThunder]

Pretty sure the sohc heads have a large space between ports 2 and 3 where the dohc heads are evenly spaced between all ports. I think 84GKSIG has both manifold and should be able to confirm

I also can confirm this: in my Celeste I now have a stock twin carb 4g63 aka Sirius engine. It has round ports and there is a large space between 2 and 3. On some engines there is a mechanical fuel pump mounted there, operated by the camshaft.

The DOHC engines have equal spaces between the ports (which can be a big one for the 1G and small for the other "G"s). I think this is because the DOHC engines are all EFI... EFI's use electrical boost pumps which give higher pressures than the mechanical pumps for carbies as you all know

Cheerz
Sven

[simon]

Hi
The magna 4g64 is a 16v the exhaust maniford has oval ports and look evenly spaced

[simon]

I have two photos here,

I have put the link up, but not sure if it will work - 1st time using this






They show a manifold off a 4G63 SOHC 8v.
In the middle is a gasket off a 4G64 SOHC 16v.
At the top of the photo is a gasket off a 4G67 DOHC 16v.
Ports in the 64 are slightly bigger and the two bottom outside bolt holes are about 1/2 a bolt holt hole out - skewed to one side. Otherwise, the rest of the stud holes and the port holes line up.

You had me worried because I had a brainwave that I could use the flange and maybe secondaries to rough build a set of extractors to start with so I went and had a look to make sure they would still fit.
I have also read that primaries should be 17 inches long and secondaries 13 inches long on a set of 4-2-1 extractors/headers. Somewhere else I read that you should use 4 into 1 extractors ? maybe for EFI motors. Does anyone have any more info on this?

Simon

[Benharjon]

Interesting! good job on the pics and this could be another option to mod for Jase!

As for primary and secondary length, i am pretty sure they can be tailored to produce better torque and power in certain places in the rpm band...

from memory 4-2-1 is essentially best for daily, and 4-1 producing optimal high rpm power. Then the lengths can be optimised for torque...

Google could probably give more precise information...

[RaptorReed]

None of our trucks came DOHC, only single cam. DOHC was only in fwd cars and our AWDs (narrowblock). Most common motors in our l200s were 4g64s, 4g54, and 6g72, 4g63Bs aren't too common.

[C_Fernance]

Another option for extractors, but would require modding, are off a Hyundai Lantra. Find a cheap set and start cutting and welding. Heres what a standard set look like fitted to a 4G61, managed to pick them up for $10 which would be cheaper then buying just the flange to build a set from scratch.

[A112H]

You're right, that would have been cheaper but I just bought this before reading your post, lol
http://www.ebay.com.au/itm/4g63-Custom- ... 35bfd0ff7e