tri-y headers and smaller exhaust system

[steve cowan]

Mate you'll be wearing out spanners with all that gear to test good work.
It will be great to see the progression of the combo one cam to the next along with all the tuning variables.
What convertor and rear suspension setup do you run?
Yes great figures from Tony's 383 you mention, thats well built street muscle for sure. Im keen to see the hp figure on his Jzed holden 6, i think he is trying to outgun my little 179 turbo 6 with it ... im sure it will awesome piece the jzed head and im not often impressed by a holden 6! Lol

Craig,
is the turbo 6 a work in progress ??
Tony sent me some photos and specs last night - it is badass there some coin tied up in that deal but going to make some pretty serious steam for sure.
the toughest 6 banger i seen in my opinion is NA 202 black lj torana runs 9.7s @ 136 aspirated it has 3 x 2 barrel dominators,5 speed liberty.i was lucky enough to see the car up close when they came up my way for 6 banger nationals,pretty amazing car,the boys keep there cards very close to there chest and dont say a whole lot.
i have 2 x converters - a locally done 9'' 4000 stall and a TCE 8'' 5600 stall thats in the car at the moment,i luv this converter it makes the car really react well no mater what combo i am running.some guys think i am on the lunatic soup running this converter and shifting the car at 6000 rpm but it runs quicker than the small converter 1.5 - 2 tenths in the 60 ft
3 tenths when i ran the as cast 215 darts and roller valve train. 1.52 60 ft .
rear end is a XA GT 9 inch that bolted straight in (HQ style side ute) small bearing deal.
modified 3 x leaf springs i done myself that i bolted together ( dont try and drill spring steel it took me a week lol and lots of broken gear but would not let it beat me) everyone said the bolts will break - has not happened and my theory is if the leaf springs dont separate that must help pushing down on the rear tyre ?? probably dumb theory but i am sticking with it.
fitted Caltracs that dont fit early holden stuff as the USA stuff shackles and eyes must be slightly different - talking 5mm in width.have Koni adjustable shocks front and rear.
have not spent a lot of time with pre load on the bars yet-there's 6 months of testing alone.

[steve cowan]

Got a bad boy 383 Holden going on the dyno in a couple of weeks, 269/272 on 108 solid flat cam, 12:1 pump fuel street motor.
Heads are COME 590 alloys, which I'm not that keen on, chamber sux, but I did get them flowing plenty 296/207 @ .650". Ex port is a little lazy, but sizing is good & it's stable.
We'll see how much the chamber hobbles it, with a set of my iron heads it'd go 580-590hp (maybe a tad more) @ 6800-7000rpm.
I've got some pacemaker 1 3/4" primary tri y pipes here to cut up for it, leaving the 2" secondaries & just adding 3" tuned collectors so he doesn't have to bolt up collector extensions for racing, just drop the pipes, bolt on the slicks & go.

i looked at those heads-
2.02 - 1.6 valve
182cc runner
advertised 300 cfm @ 0.700'' average 231 cfm
advertised 194 @ 0.700'' exhaust average 151 cfm
Tony,
i suspect your around 185-190 cc, do those heads have a pushrod restriction ?
were they much work to tidy up- valve job,SSR shaping ,throat sizing,i dont need to know the sizes but just thinking out loud,are they a reasonable casting.
i looked at a picture could not see the chamber to well-
pretty impressive pump gas 12 to 1 cant wait to hear how she runs any predictions ?? 610hp peak
520 ft/lbs

[cjperformance]

Got a bad boy 383 Holden going on the dyno in a couple of weeks, 269/272 on 108 solid flat cam, 12:1 pump fuel street motor.
Heads are COME 590 alloys, which I'm not that keen on, chamber sux, but I did get them flowing plenty 296/207 @ .650". Ex port is a little lazy, but sizing is good & it's stable.
We'll see how much the chamber hobbles it, with a set of my iron heads it'd go 580-590hp (maybe a tad more) @ 6800-7000rpm.
I've got some pacemaker 1 3/4" primary tri y pipes here to cut up for it, leaving the 2" secondaries & just adding 3" tuned collectors so he doesn't have to bolt up collector extensions for racing, just drop the pipes, bolt on the slicks & go.

Gday Tony, whats the most you have seen thru the 2" secondaries. As you know the 2" section is the cork in these once you have a 3" collector in place. With the 2" secondary pipes they 'should' top out around 615hp. The primary at 1.75" and the 3" collector can obviously support a lot more.
Cheers,

[KnightEngines]

Steve - the COME heads are too big for the 2.02" valves they come with & they don't get even close to advertised flow figures!
I put 2.055" valves in & barely touched the bowls, just blended in the valve job. I sunk the seats about .040" to try to band aid the shallow blown out chamber. Most of the work was in reshaping the short turn & squaring up the pinch. Out the box the pinch is 2.4^", they are 2.5 now. More work on the exhaust, getting the taper right & laying the turn back. Chambers are almost untouched - not much I could do when there is no metal there to start with.
Chamber looks like someone saw a picture of a Yates head & copied the shape without realising it has some depth!

I've seen 627hp through 2" secondaries, but on e85, thatd be near their limit.

That 9 sec Holden 6 has a Moodie head, looks like a stock 9 port from the outside. I just finished one for a group Nc car, it went 225cfm through a 1.74" valve, but I used a 50 deg seat & 8mm valve stem to get there.

[cjperformance]

627 very nice, e85 would have been a good help there.
Thats pushing 0.0176"sq per Hp , I usually work at a 'practical' max of 0.018"sq per Hp thru header pipes, (this is no scientific secret formula just an observed and tested base # that I have constantly tweeked after a mate and i were crunching some numbers many years ago, it does no more than give a reasonable starting baseline, as all know there are a million variables) ,some engines or headers wont see that. A few will see better. So thats friggen excellent Tony.

[cjperformance]

Steve , yeah the turbo 6 is in the build now, i had witten a little about it when i was stuck for rings viewtopic.php?f=1&t=55971&hilit=3.595
Its pretty basic really but good fun in an LJ torana on the tryres that fit in stock guards!
Have a look at some of the FAST Class drag cars, tons of good leaf spring times from these guys and very limited to what they can do so a lot of rule book bending and loophole searching!

[steve cowan]

Steve , yeah the turbo 6 is in the build now, i had witten a little about it when i was stuck for rings viewtopic.php?f=1&t=55971&hilit=3.595
Its pretty basic really but good fun in an LJ torana on the tryres that fit in stock guards!
Have a look at some of the FAST Class drag cars, tons of good leaf spring times from these guys and very limited to what they can do so a lot of rule book bending and loophole searching!

i missed that thread- just read it very cool
my second car when i was 18 years old was genuine LJ GTR XU1,ran 13.8s @ 104 fulll street trim
it was a awesome little car

[steve cowan]

Steve - the COME heads are too big for the 2.02" valves they come with & they don't get even close to advertised flow figures!
I put 2.055" valves in & barely touched the bowls, just blended in the valve job. I sunk the seats about .040" to try to band aid the shallow blown out chamber. Most of the work was in reshaping the short turn & squaring up the pinch. Out the box the pinch is 2.4^", they are 2.5 now. More work on the exhaust, getting the taper right & laying the turn back. Chambers are almost untouched - not much I could do when there is no metal there to start with.
Chamber looks like someone saw a picture of a Yates head & copied the shape without realising it has some depth!

I've seen 627hp through 2" secondaries, but on e85, thatd be near their limit.

That 9 sec Holden 6 has a Moodie head, looks like a stock 9 port from the outside. I just finished one for a group Nc car, it went 225cfm through a 1.74" valve, but I used a 50 deg seat & 8mm valve stem to get there.

Damn Tony-for the price of the heads from the manufacture you would think they would not need as much work as you have put in??

[KnightEngines]

They're less work than YT dash 9's!
That's Holden tax for you....

There is a very good reason why most of my Holden motors wear ported factory iron heads, the cost of alloys pays for a lot of porting!

[NewbVetteGuy]

Those look a little different that the Doug Thorley's. Randy had good results on an EMC engine using those.

http://www.dougthorleyheaders.com/1968- ... ders_15894

thanks for the link Jim,
if i could get a Thorley header to fit i would purchase a set but i think the left hand - right hand drive USA - AUSTRALIA configuration might not work.
yep i know Randy,CGT,Tony Knight,James (Melway) etc dyno heavy hitters use tri-y pipes
kinda where my motivation come from

I also converted/changed to smaller headers Tri-Y on my SBC. What a seat of the pants difference!

Before: 410” SBC 210cc Profiler ported heads, 1 ¾ long tubes, crower 242/252 110’ cam, 830 Holley

Now: 410 SBC 195cc ATK (profiler cast) ported heads with smaller exhaust port, 1 5/8” Dougs Tri-Y headers, Jones 236/239 cam, prosystems carb

Note the differences in these heads - Wonder what the true power difference is?
Thread on exhaust port size vs. header fitment https://www.speed-talk.com/forum/viewtopic.ph ... 1&start=30

Mtrhead, are those off-the-shelf headers with the bolt holes slotted or custom?
(I'm also looking for a set of Tri-Ys that will work with the standard Profiler heads; I am looking for a full-length rear bumper exit exhaust system, though so Dougs/ Thorleys seem "out". This leaves me with Stan's for my C3 Corvette and they're out by me, but it's a pretty old tri-y design and they won't give me a straight answer on whether they'd make a stainless header, slot the bolt holes so that it fits appropriately, and weld in O2 bungs before I send it down the street from them to have it coated. -Their price for coated stainless is getting to entry-level custom headers, too...)


Adam

[steve cowan]

Adam,
my off the shelf 1 5/8'' tri-y i am in the process of getting them on for next track day,
of course they hit the gearbox X-member so have to fix that.
i have to slot them a good 1/4 inch plus to get the roof to line up,sides are pretty good just tidy up with diegrinder.
the floor is a different story-about 1/2'' step
i am not sure whether leave it as anti reversion or i can make a header plate on the passengers side but dont have room on drivers side due to steering rack interference.
i could weld in some little tongues for a better transition.

[cjperformance]

Steve, re the large step at the bottom of the port. Different engine to what you are dealing with but on the ford cleveland stuff when using 4V(large port) heads there is an exhaust port tongue that can be bolted in between the head and the header which fills the ex port floor. This also gives a 7/16" to 1/2" step depending on the plate brand. They work really well when the primaries dont turn sharply right off on the header flange, but when the headers are turning sharp right off of the flange they are somewhere between useless or a restriction depending on the bend. Due to the port face angle and typical engine bay layout the Cleveland is more prone to need a tight bend at the header plate than a Chev in its typical engine bay but i thought its worth noting and maybe some experimenting on your combo.

20190416_091945-800x450.jpg

[steve cowan]

Craig,
Those tongues have been talked about, I am sure Bill and Randy were talking not long ago about some getting eaten up in a BBC. I got some flange plates and collector extensions 300,400,500mm this morning.
I am still thinking of welding some 1/4" flat plate into header flange opening.
It will go from 1/4"approx give or take down to nothing into the primary pipe if that makes sense.
I will put some pictures up later

[cjperformance]

Craig,
Those tongues have been talked about, I am sure Bill and Randy were talking not long ago about some getting eaten up in a BBC. I got some flange plates and collector extensions 300,400,500mm this morning.
I am still thinking of welding some 1/4" flat plate into header flange opening.
It will go from 1/4"approx give or take down to nothing into the primary pipe if that makes sense.
I will put some pictures up later

Yes haha, i have heard Bills melted tongue story!
These stainless ones last fine and other .125" mild steel ones i have used last well but do erode a little over time.
I know what you mean re about tapering down into your primary. Sounds like a good plan.

[mtrhead]

thanks for the link Jim,
if i could get a Thorley header to fit i would purchase a set but i think the left hand - right hand drive USA - AUSTRALIA configuration might not work.
yep i know Randy,CGT,Tony Knight,James (Melway) etc dyno heavy hitters use tri-y pipes
kinda where my motivation come from

I also converted/changed to smaller headers Tri-Y on my SBC. What a seat of the pants difference!

Before: 410” SBC 210cc Profiler ported heads, 1 ¾ long tubes, crower 242/252 110’ cam, 830 Holley

Now: 410 SBC 195cc ATK (profiler cast) ported heads with smaller exhaust port, 1 5/8” Dougs Tri-Y headers, Jones 236/239 cam, prosystems carb

Note the differences in these heads - Wonder what the true power difference is?
Thread on exhaust port size vs. header fitment https://www.speed-talk.com/forum/viewtopic.ph ... 1&start=30

Mtrhead, are those off-the-shelf headers with the bolt holes slotted or custom?
(I'm also looking for a set of Tri-Ys that will work with the standard Profiler heads; I am looking for a full-length rear bumper exit exhaust system, though so Dougs/ Thorleys seem "out". This leaves me with Stan's for my C3 Corvette and they're out by me, but it's a pretty old tri-y design and they won't give me a straight answer on whether they'd make a stainless header, slot the bolt holes so that it fits appropriately, and weld in O2 bungs before I send it down the street from them to have it coated. -Their price for coated stainless is getting to entry-level custom headers, too...)

Adam

The try’s I have fit. They were Doug’s on ATK profilers. Standard profilers they will not fit properly. Need to slot about 1/8-3/16”. STD as cast profilers have a significantly raised port in relation to the bolt holes. Yes Stan will make them fit. Need to send him the gasket that actually fits your profilers. Jegs sells one. Felpro does not fit. See the link I pasted. You need the GM d port fast burn style gasket and grind it! Jegs gasket does fit. (Holes are huge). Stan will make the flange. He will complain because it’s a pain. I’m speechless on why more people haven’t complained. But we all know people don’t pay much attention to exhaust pipes bolted up