Pump Gas Build some questions after dyno session..

A dual plane manifold would kill it.

Scott Foxwell wrote:

dfree383 wrote:

Scott Foxwell wrote:

Lem Evans wrote:

Scott Foxwell wrote:That's a very small intake valve and very small headers for that many cubes. Kind of odd that you'd have a Victor intake and a Dominator.

I agree about the intake valve size and headers but, I'm not sure about what you are saying about the Victor/Dominator thing.  

Big engine with small heads/valves/exhaust...doesn't need a single plane with a dominator. Apples and oranges. I would bet a Performer RPM or Stealth with a 1000hp would make a lot more average power. Focus on the rpm range this engine is most efficient in.

I disagree, a 4150 and dual plane will kill this engines real performance running down the road .

Might appear better on the dyno below 3000 but will weeze out

It already weezez out. This thing is done at 6000 with these heads and exhaust and it's only using 1000cfm. No sense in trying to make it do something it doesn't want to do. Big dual plane and big 4150 would make this thing a monster from 3500 to 5500. It'll probably live it's life way more in that rpm range than above 6000. The single plane and dominator aren't doing anything for it down there and the engine isn't going to make any power where they would help.
Physics are physics.

The heads are big enough to feed this as a street engine, I'm thinking it's got something going on in the tune or valve train harmonics

The headers won't matter once the exhaust is on

Cam may need a little more exhaust duration - or less intake - agreed, not sure 28 degree @ 0.050" split is warranted.
The headers used on this build would be tiny on a 460.
I don't agree that headers make no difference once exhaust is bolted up.
Tiny straw headers are choking this thing.
Better headers and a full 3" or 3.5" exhaust will make for a significant power increase.

Just my opinion of course.

Cheers

Sorry guys .. i should of laid out the focus of this engine build from the start..my apologies.. the owner likes to cruise to car shows and club runs twice a month max.
Needs to be able to drive around for up to an hour if need be with reasonable manners having power brakes etc..so can't go real crazy with the cam profile in the interests of reliability..

He also likes to race at nostalgia or street meets quarter mile 4 or 5 times a year for fun not a (serious hardcore guy)..his previous milder pump gas 501ci in the car ran 11.3 at 125mph with 3.25 gears (way too tall) 28 tires. at a heavy 3900lbs..

He would like to run deep into the 10's..with the 588ci.
Now has 3.7 gears
c6.. converter flashes to around 4200 4400
28 X 11.5 slicks at the moment..could go taller and a little wider
Full exhaust twin 3 and magnaflows.. (as most race meets have to run mufflers.)

The compcams extreme street roller 266 272 @.050 (measured at 264.5  271 @.050) 111 lobe sep.. has pretty reasonable street manners and decent vacuum for the brakes..he has been driving it for about 8 months with no problems

My question is should i start with the camshaft (i'm guessing here) a little less or more intake duration?.. and possibly alot more exhaust duration..would much bigger exhaust duration effect driveability and vacuum alot..?
Or is that of limited value until i address other issues in the combo first intake valve, headers, exhaust any possible valve train issues etc..

If it has vacuum brakes you'll have to cam the brakes not the engine.

nascar429 wrote:2 inch primary.. 2 1/4 intermediate.. 3 inch collector..  not terrible pipes but not great either.

what headers are those?

rmcomprandy wrote:

Lem Evans wrote:

nascar429 wrote:Nothing to write home about Dave.. for the sum of it's part's Hp wise...
588ci 4.560 x 4.500 stroke
QFX 1150 dominator reworked by Competition Carbs..runs great on the street.
Ported plenum Victor, with jomar 1 inch tapered spacer.
standard tension rings 1/16 1/16 3/16.
Dynoed with Tri y headers 2" inch primary's, 2 1/4 intermediate, 3" inch collector not the best..only off the shelf ones available for the car.
runs on 93 octane here in Oz.. i'll attach another dyno sheet with the other details..

   

Did you guys ever pull it low enough to find peak tq?

This dyno sheet does not represent what you seem to be trying to accomplish with this engine / vehicle combination.
Personally, I would use dual-quads on a ported Blue Thunder intake manifold and let it make the most torque it can and  have no worries about the horsepower above 5,500 RPM.

Heck yeah, that would work!! I had a Buddy Barr dual quad on my 429 and it worked VERY well.

nascar429,
Spend the money to modify the bottom half of the "extractors" . Cut at the "Y" and go to 2-1/2 " 16-18"s long and a 3-1/2", non merging collector about 12" long. It's too big of an engine to be choked like it is in the pictures.

nascar429 wrote:Sorry guys .. i should of laid out the focus of this engine build from the start..my apologies.. the owner likes to cruise to car shows and club runs twice a month max.
Needs to be able to drive around for up to an hour if need be with reasonable manners having power brakes etc..so can't go real crazy with the cam profile in the interests of reliability..

He also likes to race at nostalgia or street meets quarter mile 4 or 5 times a year for fun not a (serious hardcore guy)..his previous milder pump gas 501ci in the car ran 11.3 at 125mph with 3.25 gears (way too tall) 28 tires. at a heavy 3900lbs..

He would like to run deep into the 10's..with the 588ci.
Now has 3.7 gears
c6.. converter flashes to around 4200 4400
28 X 11.5 slicks at the moment..could go taller and a little wider
Full exhaust twin 3 and magnaflows.. (as most race meets have to run mufflers.)

The compcams extreme street roller 266 272 @.050 (measured at 264.5  271 @.050) 111 lobe sep.. has pretty reasonable street manners and decent vacuum for the brakes..he has been driving it for about 8 months with no problems

My question is should i start with the camshaft (i'm guessing here) a little less or more intake duration?.. and possibly alot more exhaust duration..would much bigger exhaust duration effect driveability and vacuum alot..?
Or is that of limited value until i address other issues in the combo first intake valve, headers, exhaust any possible valve train issues etc..

We can prove real easy the camshaft is not correct. Loosen intake lash by .004". Tighten exhaust lash .010". She will sound better, throttle response will better, and vacuum will be better. Guaranteed!!!!!!!!!

Has the owner run down the 1/4 mile yet?
750 HP and a boat load of torque should get 4000 lbs well into 10's - even as it sits.
Better header would certainly pick up some top end -


Should be an easy deal to get to 1.4 HP per cubic inch. ( 823 hp)

Cheers

Lem Evans wrote:If it has vacuum brakes you'll have to cam the brakes not the engine.

Haha.. very good point!!

SLord82 wrote:

nascar429 wrote:2 inch primary.. 2 1/4 intermediate.. 3 inch collector..  not terrible pipes but not great either.

what headers are those?

There pacemaker headers to suit our falcons here in oz...only BBF header available here for us besides custom 4 into 1's..

gt350hr wrote:nascar429,
     Spend the money to modify the bottom half of the "extractors" . Cut at the "Y" and go to 2-1/2 " 16-18"s long and a 3-1/2", non merging collector about 12" long. It's too big  of an engine to be choked like it is in the pictures.

That's a very good idea..and something i've been thinking about doing.. people have done that mod on these pipes here with success on some race motors i've seen..i tried it on a 498ci pump gas streeter 16 years ago it lost torque on the chassis dyno.. about the same peak hp.. and throttle response was abit soft.
but this 588ci engine is alot stronger.. i still have them pipes hanging but cut the 3-1/2" collector off and went back to a 3 inch collector..i may modify them to similar lengths you are talking about with the 3-1/2" collector..worth a try.

dfree383 wrote:
The heads are big enough to feed this as a street engine,

A 588 with a 2.20 intake valve???
lol... hardly.

Straubtech wrote:

nascar429 wrote:Sorry guys .. i should of laid out the focus of this engine build from the start..my apologies.. the owner likes to cruise to car shows and club runs twice a month max.
Needs to be able to drive around for up to an hour if need be with reasonable manners having power brakes etc..so can't go real crazy with the cam profile in the interests of reliability..

He also likes to race at nostalgia or street meets quarter mile 4 or 5 times a year for fun not a (serious hardcore guy)..his previous milder pump gas 501ci in the car ran 11.3 at 125mph with 3.25 gears (way too tall) 28 tires. at a heavy 3900lbs..

He would like to run deep into the 10's..with the 588ci.
Now has 3.7 gears
c6.. converter flashes to around 4200 4400
28 X 11.5 slicks at the moment..could go taller and a little wider
Full exhaust twin 3 and magnaflows.. (as most race meets have to run mufflers.)

The compcams extreme street roller 266 272 @.050 (measured at 264.5  271 @.050) 111 lobe sep.. has pretty reasonable street manners and decent vacuum for the brakes..he has been driving it for about 8 months with no problems

My question is should i start with the camshaft (i'm guessing here) a little less or more intake duration?.. and possibly alot more exhaust duration..would much bigger exhaust duration effect driveability and vacuum alot..?
Or is that of limited value until i address other issues in the combo first intake valve, headers, exhaust any possible valve train issues etc..

We can prove real easy the camshaft is not correct.   Loosen intake lash by .004".   Tighten exhaust lash .010".   She will sound better, throttle response will better, and vacuum will be better.  Guaranteed!!!!!!!!!

It's a great way to find out real quick how the engine responds and costs nothing!..i'll be trying it soon.. after i fit a new gearbox in the next few weeks as it is just about shot..i'll let you know how i go...Thanks for the tip!!..

Scott Foxwell wrote:

dfree383 wrote:
The heads are big enough to feed this as a street engine,

A 588 with a 2.20 intake valve???
lol... hardly.

Still enough valve and head to make a very potent street engine.

If you put a lot more cam in the thing the convertor will need to be addressed. Otherwise the et could slow down.

68galaxie wrote:

Scott Foxwell wrote:

dfree383 wrote:
The heads are big enough to feed this as a street engine,

A 588 with a 2.20 intake valve???
lol... hardly.

Still enough valve and head to make a very potent street engine.

Based on the math the 2.200 will support it to 5800 rpm. After that it is a restriction.

Here is what the engine wants:

.689/670
258/276
107 LSA

Will make more average HP and torque by 41HP and 58#/ft then what is in it.

Scott Foxwell wrote:

dfree383 wrote:
The heads are big enough to feed this as a street engine,

A 588 with a 2.20 intake valve???
lol... hardly.

It's not a race engine and will function just fine

dfree383 wrote:

Scott Foxwell wrote:

dfree383 wrote:
The heads are big enough to feed this as a street engine,

A 588 with a 2.20 intake valve???
lol... hardly.

It's not a race engine and will function just fine

Don't build many race engines here, the engine still requires a given amount of valve area to make power and run efficiently. You don't want the intake valve to be a restriction. To choke the air at the valve is the worst place you can do it. The Boss 302 didn't need a 2.19 intake valve but it got it. The 351C with 4V heads didn't need a 2.19 but they got them. They came in production cars.

Straubtech wrote:

68galaxie wrote:

Scott Foxwell wrote:

dfree383 wrote:
The heads are big enough to feed this as a street engine,

A 588 with a 2.20 intake valve???
lol... hardly.

Still enough valve and head to make a very potent street engine.

Based on the math the 2.200 will support it to 5800 rpm.  After that it is a restriction.

Okay that's with a 588". What's the math say about 547"? 4.400" x 4.5" 6.700" rod.

Lem Evans wrote:

Straubtech wrote:

68galaxie wrote:

Scott Foxwell wrote:

dfree383 wrote:
The heads are big enough to feed this as a street engine,

A 588 with a 2.20 intake valve???
lol... hardly.

Still enough valve and head to make a very potent street engine.

Based on the math the 2.200 will support it to 5800 rpm.  After that it is a restriction.

Okay that's with a 588". What's the math say about 547"? 4.400" x 4.5" 6.700" rod.

Email me the engine specs and the rpm range you want the power.

Straubtech wrote:

Lem Evans wrote:

Straubtech wrote:

68galaxie wrote:

Scott Foxwell wrote:

dfree383 wrote:
The heads are big enough to feed this as a street engine,

A 588 with a 2.20 intake valve???
lol... hardly.

Still enough valve and head to make a very potent street engine.

Based on the math the 2.200 will support it to 5800 rpm.  After that it is a restriction.

Okay that's with a 588". What's the math say about 547"? 4.400" x 4.5" 6.700" rod.

Email me the engine specs and the rpm range you want the power.

I was just asking at what rpm the 2.200" valve would be the restriction in a 547".

Lem Evans wrote:

Straubtech wrote:

Lem Evans wrote:

Straubtech wrote:

68galaxie wrote:

Scott Foxwell wrote:

dfree383 wrote:
The heads are big enough to feed this as a street engine,

A 588 with a 2.20 intake valve???
lol... hardly.

Still enough valve and head to make a very potent street engine.

Based on the math the 2.200 will support it to 5800 rpm.  After that it is a restriction.

Okay that's with a 588". What's the math say about 547"? 4.400" x 4.5" 6.700" rod.

Email me the engine specs and the rpm range you want the power.

I was just asking at what rpm the 2.200" valve would be the restriction in a 547".

Much above 6000 and it's going to be limiting.