Another "How much will it make?" Project "Special Needs"

[wyrmrider]

that's either the way I feel today or my wife's opinion
sigh

[steve316]

I have been told to get a life and go with the flow.

[randy331]

Just spotted this on DV short vs. Long stroke 383 thread. Interesting how the bigger bore got the larger valve but really only made a difference in the llf. The large bore, short stroke, larger intake valve with wider lc was the clear winner. Interesting. What I would do is get a large diameter junk valve and match it to whatever your top cut is. 35 degrees I think. Not touching the existing valve job. Then flow it. Little work and may shine some light. Just an idea. Thanks, Charlie

After the EMC I did a set of heads for someone else that we tested on the EMC engine first, just hoping to learn something. Emc heads had 2.08" valve, the other set tested had 2.02" valve, both with 50* seats. After 1/2 a day of testing we had the smaller valve heads scoring just as good. It wanted the same advance in the cam, the same jets in the carb, loose in lash and tight ex lash for best score, just like the bigger valve heads liked.
We only tested the same Comp Cam we used at the competition.
Both heads had the same peak flow, but the smaller valve was down a bit below .300". Don't have the numbers in front of me, but I'm sure the smaller one was considerably down below .150" lift. I never test heads down low anymore, unless someone asks for it.

Thought it interesting they scored the same. Would have liked to spend more time on the smaller valve set, ( cams etc ) to see if they could have ended up better.

On a side note, I just took my new 355 cube work truck engine for a drive.
Has very lightly ported 062 vortecs 1.94"/1.5" valves and dare I say it???..... 50* seats on both in and ex.
204/214 @ .050 cam and .420/.442 lift.

Randy

[Old School]

On a side note, I just took my new 355 cube work truck engine for a drive.
Has very lightly ported 062 vortecs 1.94"/1.5" valves and dare I say it???..... 50* seats on both in and ex.
204/214 @ .050 cam and .420/.442 lift.

Randy

I thought I had something to say but with all the atrocities you have committed I am speechless. First, 50* seats with only a little over .400 lift. How will the engine even breath, no low lift flow, it will only be able to access flow from .200-.420. Everyone knows that you should have a 30*seat with that lift, maybe take a chance and go to a 38*. Second, a generic white box cam. It bet it was used from lesssons learned years ago with the Nova. Anyone with an internet education would know this combination would not run unless you have a custom cam designed taking into account intake/exhaust flow and percentages. Is the cam ground on 112? Another disaster waiting to happen. This goes against everything I have learned on the internet. And those tiny valves......

Seriously, I am interested in how the 50* will affect fuel efficiency. Everything is over-analyzed but I could see maybe improved fuel mileage? Best of luck with your new engine.
Billy

[randy331]

a side note, I just took my new 355 cube work truck engine for a drive.
Has very lightly ported 062 vortecs 1.94"/1.5" valves and dare I say it???..... 50* seats on both in and ex.
204/214 @ .050 cam and .420/.442 lift.

Randy

I thought I had something to say but with all the atrocities you have committed I am speechless. First, 50* seats with only a little over .400 lift. How will the engine even breath, no low lift flow, it will only be able to access flow from .200-.420. Everyone knows that you should have a 30*seat with that lift, maybe take a chance and go to a 38*. Second, a generic white box cam. It bet it was used from lesssons learned years ago with the Nova. Anyone with an internet education would know this combination would not run unless you have a custom cam designed taking into account intake/exhaust flow and percentages. Is the cam ground on 112? Another disaster waiting to happen. This goes against everything I have learned on the internet. And those tiny valves......

Seriously, I am interested in how the 50* will affect fuel efficiency. Everything is over-analyzed but I could see maybe improved fuel mileage? Best of luck with your new engine.
Billy

I now have a name for the work truck engine.

Atrocity it is.

My son rode with me on test drive. Said I think this old 85 3/4 ton will beat my 05 1/2 ton.
Hope the fuel mileage is there and I'll be happy with it.

Randy

[steve316]

Napa Larry spec cam, how could it be anything other than a runner.

[CGT]

Atrocity it is.

And an atrocity it will be when your valve job only lasts 200 miles. 45 deg seat=200,000 mile. 50 deg seat=high leakdown after 100 miles or so. Come on....use your head here! I thought I'd just add to some of the sarcasm.

[steve316]

Glad it was sarcasm, I though my last valve job would be coming next week for a redo.

[randy331]

But what about "optimizing" the overlap period, opening the valve sooner relative to piston demand and basically focusing more on the first half of the stroke rather than the last half.

How would one go about deciding overlap was, or wasn't optimized ?
And how would one go about deciding the first half of the stroke needed more/less focus vs the second half.

I mean other than just trying more camZ that have more/less overlap, or more lift/time/area in the first half and less in the second half and looking at results, what do you look at to decide one of these isn't already optimum??

Randy

[Carnut1]

a side note, I just took my new 355 cube work truck engine for a drive.
Has very lightly ported 062 vortecs 1.94"/1.5" valves and dare I say it???..... 50* seats on both in and ex.
204/214 @ .050 cam and .420/.442 lift.

Randy

I thought I had something to say but with all the atrocities you have committed I am speechless. First, 50* seats with only a little over .400 lift. How will the engine even breath, no low lift flow, it will only be able to access flow from .200-.420. Everyone knows that you should have a 30*seat with that lift, maybe take a chance and go to a 38*. Second, a generic white box cam. It bet it was used from lesssons learned years ago with the Nova. Anyone with an internet education would know this combination would not run unless you have a custom cam designed taking into account intake/exhaust flow and percentages. Is the cam ground on 112? Another disaster waiting to happen. This goes against everything I have learned on the internet. And those tiny valves......

Seriously, I am interested in how the 50* will affect fuel efficiency. Everything is over-analyzed but I could see maybe improved fuel mileage? Best of luck with your new engine.
Billy

I now have a name for the work truck engine.

Atrocity it is.

My son rode with me on test drive. Said I think this old 85 3/4 ton will beat my 05 1/2 ton.
Hope the fuel mileage is there and I'll be happy with it.

Randy

Are you able to post up some before and after flows on these heads? Thanks, Charlie

[randy331]

Are you able to post up some before and after flows on these heads? Thanks, Charlie

No, didn't worry about it. I'm sure it has enough flowZ for a 355 driving around at part throttle in the 2000-3000 rpm range.

But I have a pretty good idea what the 50* did to the flowZ.

Randy

[CGT]

Are you able to post up some before and after flows on these heads? Thanks, Charlie

No, didn't worry about it. I'm sure it has enough flowZ for a 355 driving around at part throttle in the 2000-3000 rpm range.
How long before "Atrocity " makes its way into the Nova?

But I have a pretty good idea what the 50* did to the flowZ.

Randy

How long before "Atrocity" makes its way into the Nova?

[randy331]

But what about "optimizing" the overlap period, opening the valve sooner relative to piston demand and basically focusing more on the first half of the stroke rather than the last half.

How would one go about deciding overlap was, or wasn't optimized ?
And how would one go about deciding the first half of the stroke needed more/less focus vs the second half.

I mean other than just trying more camZ that have more/less overlap, or more lift/time/area in the first half and less in the second half and looking at results, what do you look at to decide one of these isn't already optimum??

Randy

No opinion?, ok, let me rephrase the question.

SN liked the cam in at 110* ICL for best average and peak power.
It made more below about 4500 or so with the cam in at 106* ICL.

With the cam in at 110* ICL the actual valve window area at TDC is .415" csa for intake and .576" csa for ex.
With the cam in at 106* ICL the actual valve window area at TDC is .507" csa for intake and .494" csa for ex.
These window areas are actual window CSA taking into account the seat angles used.

What does SN like about the 110* ICL?
Does SN need more window area @ TDC overlap?
Would you open the in valve earlier to add window area @ TDC?
Close the ex valve later to add window area @ TDC?
What would you change/move to give SN the best of both the 106* ICL power curve and the 110* ICL power curve?

Randy

[randy331]

Are you able to post up some before and after flows on these heads? Thanks, Charlie

No, didn't worry about it. I'm sure it has enough flowZ for a 355 driving around at part throttle in the 2000-3000 rpm range.
How long before "Atrocity " makes its way into the Nova?

But I have a pretty good idea what the 50* did to the flowZ.

Randy

How long before "Atrocity" makes its way into the Nova?

The short block has already been in the nova. Cam and all.

Randy

[RevTheory]

I'm not trying to ignore you, Randy. I'm in the thick of some health issues and I don't know if I'm afoot or horseback right now.