[cobalt327]

Originally Posted by cdminter59

I checked a few out a few cams out on CamQuest6, comp cams simualator. First the
292H-2500-6500, .501/.501, 244/244 @ .050, 351hp@5500 & 377@4000 torq.

XE284H-2300-6500, .507/.510, 240/246 @ .050, 359hp@5500 & 388 torq.

280H-2000-6000, .480/.480, 230/230 @.050, 351hp@5000 & 400@4000 torq.

XE274H-1800-6000, .490/.490, 230/236 @ .050, 358hp@5500 & 405@ 4000 torq

XE268H-1600-5000, .477/.480, 224/230 @ .050, 354hp@5000 & 411@ 3500 torq

With the IVC closing on all of these cams the DCR is 7.6-8.4 which is good for pump gas. These numbers are based on a dual plane and 750 cfm carb. Pocket porting the heads gains around 40HP. Single plane intake and large tube headers can gain 10-15hp each.

Who's gonna be the first to say "But we don't race dyno sim programs!". But good job putting this together. Regardless of the actual numbers, what it shows best is the relationship between the different durations.

And judging by what I see, the XE268H ain't that bad, either. Especially w/the mild gears and stall. Comp's dyno sheet has it down for 342 HP @ 5000 RPM and 413 ft/lbs @ 3800 RPM using Dart S/R's and a 3310 Holley. Probably long tube headers too. Manifold Vacuum is 15.5" Hg @ 800 RPM & 17" Hg @ 1000 RPM w/ no load.

BTW, Comp also has a dyno sheet on the XE274H, it shows 369 HP @ 5900 RPM and 410 ft/lbs @ 3900 RPM using same parts as above. Manifold Vacuum: 11" Hg @ 800 RPM & 14" Hg @ 1000 RPM w/ no load. Get this one ground on a 108 LSA...

The rest of their cams w/dyno sheets are here.

[F-BIRD'88]

Get this one ground on a 108 LSA...

With the shorty 3rd gen camaro headers you are better off with a wider LSA
110 to 114.

If it had long tube headers the 108 LSA grind is good.

The cam has to match the exhaust system. They work together.

You can move the 110LSA cam a bit to a 104 Intake C/L on install if you want.
Or install stock on the 106 C/L.

The exhaust system will make or break this combo.
Very hard to buy a good exhaust system for these cars.
But you can build a really good one using components.

the 2.5" y'd into 3.5" single is known as the "Big Mouth" exhaust system for this car. You can build it your self using teh Flowmaster Y and Dyno max tube bends and straights and the Magna flow muffler, yourself for a fraction of the cost. Its a powerfull exhaust system that enhances the shorty headers, fits the 3rd gen F body car and makes power and torque.

Another cam I like for this specific combo is the Crane H278-2 (HMV278-2) with a 1.6 rocker on the intake side.
This car will run very well with any all these cams.

[454C10]

My 2800 car (with me in it) ran trapped at 120mph in the 1/4 mile with a 292H, 200cc dart iron eagles heads, 10.5:1 350, full length headers, rpm intake, and a 3310 750 holley. 3.90 gear and T5 manual trans

That is 370 hp at the tires

beat the hell out of that engine for 10 years. cam finally when flat when they changed the oil formulation

[cobalt327]

Personally I never run "shorty" headers- do what it takes to get it right.

[vinniekq2]

454 that sounds like a 10 second car

[F-BIRD'88]

Originally Posted by cobalt327

Personally I never run "shorty" headers- do what it takes to get it right.

Me neither but when you build the rest of the exhaust system and match up the camshaft grind specific valve open close events, they are not too bad.

[painted jester]

F birds "Y" pipe is interesting, reminds of the Tri Y headers I dyno'ed the Tri Ys! The increase in hp and torq was quite a bit more then street headers and fell just short of tuned competition headers till they entered higher rpms! over 5500rs! I guess that works on the same principle for scavenging!

I never ran shorty's either.

Jester

[vinniekq2]

PJ, when were the tri Ys popular? I think Jere made the 4 into1s starting 1964? just before my time...lol.

[painted jester]

Originally Posted by vinniekq2

PJ, when were the tri Ys popular? I think Jere made the 4 into1s starting 1964? just before my time...lol.

I saw the first in the early 60s, at Detroit drag way they called em 421s (4 into 2 into 1) I think they were made by Cheetah Or Black Jack! LOL

My dyno tests were in the the mid 80s! But they were really popular in the mid 70s and early 80s here! and are still produced! they were also used on a lot of Honda 750 racing motorcycles!

Jester

[F-BIRD'88]

Well not really the same as a tri Y.
The Idea of joining the two banks together with this Y pipe is
1. It fits the car. A 2 into 1 exhaust system fits this specific car much better.
2. to make the total system exhaust system scavedging a lot better. (more mid range torque)
The engine sees it as of the header primarys are longer than they are.

[F-BIRD'88]

The Y looks like this under the car

[gearheadslife]

292

your 84 z will be happy without a little low end..
unless oh course you've reworked the whole car..
the facory set up.. a weak v6 with iroc wide tires can turn them over.lol

the car will be faster on the street with a softer lower end, that'll get you moving, roasting tires=fun but not fast

[454C10]

Originally Posted by vinniekq2

454 that sounds like a 10 second car

runs mid 11's at 120. Being a manual shift and a weak t5, I shift the gears slow. however, runs mid 10's at 135 with I use the 150 to 200 no2 shot. 6.9 at 110 1/8 mile on n02. 71 240 zcar (datsun)

[F-BIRD'88]

Originally Posted by gearheadslife

292

your 84 z will be happy without a little low end..
unless oh course you've reworked the whole car..
the facory set up.. a weak v6 with iroc wide tires can turn them over.lol

the car will be faster on the street with a softer lower end, that'll get you moving, roasting tires=fun but not fast

its very easy to get these cars to "hook".
Starting with the right tires. You can put all the torque to the ground
and leave your combo in the dust on acceleration.
You cannot make a car faster by killing off power. Like overcamming it.
The big top end will not be realized with the 292H with this exhaust system.

My car will yank the front wheels of the ground from a light in all street trim.
The way I run it at the track is the same as the street setup.
Its just that the track is the right place for that.

You want to put garbage tires with no traction on your car go ahead.
You will never make up the difference.

you do not want to or need to kill off low mid grunt.
You just need some basic traction.
this car weights almost 1000 lbs more than a 240Z w a SBC and 4 speed.

[gearheadslife]

Originally Posted by F-BIRD'88

its very easy to get these cars to "hook".
Starting with the right tires. You can put all the torque to the ground
and leave your combo in the dust on acceleration.
You cannot make a car faster by killing off power. Like overcamming it.
The big top end will not be realized with the 292H with this exhaust system.

My car will yank the front wheels of the ground from a light in all street trim.
The way I run it at the track is the same as the street setup.
Its just that the track is the right place for that.

You want to put garbage tires with no traction on your car go ahead.
You will never make up the difference.

you do not want to or need to kill off low mid grunt.
You just need some basic traction.
this car weights almost 1000 lbs more than a 240Z w a SBC and 4 speed.

I had a 9's t/a (1988 3390 lb ) mid 10's (1980 turbo 400) , you have to rework the car to get any real traction out of that 3rd gen set up.

love to see a vid of it hanging tires on the street, on dot tires

so a 240z is 2200lb's?