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LC 253 Exhaust


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#1 Lc69

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Posted 08 April 2017 - 04:58 PM

Hi gents, im interested to hear your opinions/experiences on the best approach to fitting a exhaust to an LC with a V8.
Motor is a mild pre-pollution red 253, for street use.
Looking for minimal modification, factory style setup.

Assuming the steering must be moved over 15-20mm at this stage, with x2 LH type uni joints.

Is it best to stick to std cast headers?
Do the late model VN, VR, tube headers work?
Extractors...Castle, etc....any of these fit without modification? I've read mixed feedback.

Thinking a basic 2.25" or 2.5" single system would be a practice solution?

Edited by Lc69, 08 April 2017 - 04:59 PM.


#2 gtrboyy

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Posted 08 April 2017 - 05:55 PM

Early heads like on red/blue 253/308 are siamese port spacing where as later 5l efi heads are symetrical.

 

From memory you use commodore on one side & kingswood on the other...forget which side being several years ago but only needed 1 knuckle just moved steering over in slots,more clearance with aussie/trimatic pattern...do remember most casties being broken or cracked.

Also tried set of 2 piece hurricane extractors,top half good bottom sections major mods/remade most of it...still got the mongrels lol.

 

 

 

With efi heads had to go 2 knuckles,clearance block a little bit then got calais/statesman/hsv steel headers..cut bottoms off at weld joint then new mandrel to suit car.

 

Best to decide what engine & driveline you ultimately want in car..tbh 253 is snail compared to basic efi 304



#3 Lc69

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Posted 08 April 2017 - 06:44 PM

Engine is pre pollution 253 with Aussie 4 speed.
Happy to start off with a snail, something about the period correctness.....kinda.

One uni joint? I assume to replace the std rubber coupling?
I'm trying to picture how that works without looking at the steering rack.
Wouldn't there be a misalignment issue?

I would be very interested to hear more about the best cast manifolds to use if anyone remembers which ones to use exactly.

I've been wondering about block huggers, two piece, etc. seems they all end up being modified.

#4 gtrboyy

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Posted 08 April 2017 - 08:43 PM

Yeah just used the one lh knuckle..they swivel & as long as not steep angle they're fine.Did have worn spare rack we elongated holes a tad so it lined up straighter,ironically was best setup just didn't like wider efi blocks with th700 or getrag combinations.

 

Do remember thinking was more direct/responsive than 2 knuckle setup later on but partly because new aftermarket knuckles & 'cotter pins' were soft as butter.

 

Needed a dropbase aircleaner to get it all under bonnet with rebuilt quaddie,drove nice other than v8 rumble,was only good for burnouts so put in rebuilt red 308 then went back to what I grew up on..efi 5 litres.

 

You'll either have to do cable or hydraulic conversion depending on bellhousing if dont have all worn out rat trap parts to rebuild.

 

Used to be lj v8 conversion sticky with all this info/pics on old forum or info page thing.



#5 Lc69

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Posted 08 April 2017 - 09:27 PM

Ok, great. Thanks for the info.
Leaning towards malwood hydraulic clutch setup. Underdash pedal assembly and hydraulic throw-out bearing.
Keeping my mind open, could use UC belhousing and cable.

Have been looking at the various threads on this, but there seems to be lots of opinions on exhaust.
A few selling headers for the task, but plenty of people suggest they need to be modified to work.
i have HQ style factory manifolds, but it sounds like one side may not be the best option?

#6 gtrboyy

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Posted 09 April 2017 - 06:32 PM

Try your headers since already got a set there.

 

Yeah you'll get various opinions mainly comes down to no 2 cars or being exactly same + they're damn old.

 

Might be drivers side outlet where one model has flange aiming at steering while another model just enough angle that can clear with press bend.

 

They're fairly tight under vaguely remember certain fitting sequence once engine in take spark plugs out so can slide headers in then can fit lh/x alternator bracket etc

 

Dont forget neeed to trim/weld outrigger lip & use smaller hi-torque starter.



#7 _ljmaz_

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Posted 16 April 2017 - 11:11 PM

Hi, just remember patience with this one!

 

I am currently running a 308 with headers in a 4 door LJ with trimatic. I went with dual LH knucles to improve room on the drivers side for extractors (whole steering moved over an inch. Would have been a lot easier with standard cast headers (I had a set each of HQ and Commodore cast to use) as this had some implications for my brake booster.

 

However, I had extractors to suit in pieces to suit and while the engine was being lowered in I thought I would try. I ended up bolting them on and getting the exhaust shop to tack weld the rest of the unit to suit. This allowed me to get the best fit. Was even able to fit a standard starter motor.

 

A 2.5 inch exhaust would be fine for your application.

 

You might need to get creative (tool/technique) with removing spark plugs and various other items, buts thats part of the "fun".

 

Good luck!

 

PS: my first mod LJ was with a stock 253. Was a nice experience to get it all set up and then allow me time to get my 308 ready. Having said that, i'd rather do all the paper work, just the one time.






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