512Stroker
We are all here because we are not all there.
Was the cam ground with +4* advance?
W2 408 Dyno results today !
- Thread starter mbaird
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Rat Bastid
Dunamis Metron
512Stroker
We are all here because we are not all there.
OK 4* ground in.
I missed that on the card I will go back and look again.
So did the OP install it straight up or was the cam installed with another 4* of advance as stated?
512Stroker
We are all here because we are not all there.
OK Rat school me how do you get 4* advanced off this card?
What am I missing?
Thanks in advance
Rat Bastid
Dunamis Metron
To go in straight up the intake numbers would be 15/51 and the exhaust numbers would be 53/17. That moves everything back (retarded) 4 degrees to straight up. Hope that makes sense.
Top of that dyno sheet says 460 displacement & 4.392 bore, Just saying !Gotta make a liar outta me
Idk how clear it is, but mine noses at 72-7300. Guess my memory was of a touch. Peak was 608. It carries around 580 through 7200.
Not sure which one you are more interested in for comparison sake. But I would think OP's engine should be similar to the attached sheet. I uploaded my cam card for gigs also. I have a touch more duration, but he has more lift, and more head flow. Maybe not enough spring?
You got me on the BPE. Looks like we shut them off at 6000. I swore we turned them a little harder, but again those are street engines made to live forever. I don't have the "real" one handy on a Sunday. Just the one on the website.
View attachment 1715816635
View attachment 1715816655
EDIT: Sorry...those pics are crap.
Are you saying it should have been installed straight up ?
Rat Bastid
Dunamis Metron
Not at all. 512stroker was asking if you cam had 4 degrees advance ground into it and I said it does. You can figure it out by looking at the timing numbers. That’s all we were discussing.
RAMM
Well-Known Member
I saw that too, but it may just be what was entered prior-won't effect measured HP/TQ but it will throw off VE/ME/BMEP and a few others . J.Rob
512Stroker
We are all here because we are not all there.
All righty than.
Assuming Rat is correct and the cam has 4* advance ground in.
And you installed it adding +4* of advance
That would mean you have the cam in @ +8* advanced cam timing.
If true, the question then is what will this do to the performance?
thats my engine, he just didn't change the description. was there when he ran it, and there when he printed them.
PRH
Well-Known Member
If one degrees the cam in during installation, then all possible variables would be eliminated........ and you’d know where it was installed.
PRH
Well-Known Member
I’ve never tested with this arrangement.
But for a typical street strip build....... frankly, it looks like “TMI” to me.
We have two O2’s...... one for each side.
With that much A/F data, seems like you could easily lose track of other aspects of tuning the motor and spend too much time chasing distribution issues around........ that aren’t easily corrected with simple carb changes.
Perhaps I’d have a different take on it if I used a set up like that for a while, but I know how quick a day on the dyno gets used up........ and there are other things I like to go over.
Generally, I chase the jetting around based on power output, and primarily use the A/F ratio numbers to verify things aren’t getting lean enough to hurt something.
Most combos don’t make the best power when they’re lean enough to hurt parts....... so if you tune for power, they end up safe.
But, occasionally you run across one where you have to be careful and know when to stop leaning it out.
My gut feeling is, based on the O2 readings and bsfc numbers, if one just ignored the A/F ratio numbers and just tuned for power....... there were some ponies there for the taking.
But for a typical street strip build....... frankly, it looks like “TMI” to me.
We have two O2’s...... one for each side.
With that much A/F data, seems like you could easily lose track of other aspects of tuning the motor and spend too much time chasing distribution issues around........ that aren’t easily corrected with simple carb changes.
Perhaps I’d have a different take on it if I used a set up like that for a while, but I know how quick a day on the dyno gets used up........ and there are other things I like to go over.
Generally, I chase the jetting around based on power output, and primarily use the A/F ratio numbers to verify things aren’t getting lean enough to hurt something.
Most combos don’t make the best power when they’re lean enough to hurt parts....... so if you tune for power, they end up safe.
But, occasionally you run across one where you have to be careful and know when to stop leaning it out.
My gut feeling is, based on the O2 readings and bsfc numbers, if one just ignored the A/F ratio numbers and just tuned for power....... there were some ponies there for the taking.
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512Stroker
We are all here because we are not all there.
Machine shop that did the shortblock degreed it @ 4* advanced... whether that means straight up due to built in advance or an additional 4* is a question I need to ask . This shop builds race engines exclusively so I have to imagine they did it correctly.
PRH
Well-Known Member
People really should just stop using the “advanced” or “retarded” terminology.
It almost always leads to a thread getting sidetracked.
Best to talk in terms of lsa and installed position.
Like: “cam is ground on a 108, installed at 104”.
Then it’s clearly spelled out(as well as showing it was degreed).
It almost always leads to a thread getting sidetracked.
Best to talk in terms of lsa and installed position.
Like: “cam is ground on a 108, installed at 104”.
Then it’s clearly spelled out(as well as showing it was degreed).
PRH
Well-Known Member
Frankly, I’d suspect a sensor issue on that cyl.
Everyone who does dyno testing has there own way of going about things.
I often see/hear about things people are doing on the dyno that make no sense to me.
I’ve had 31 years to come up with how I do things........ many of which would probably make other dyno operators scratch their heads.
stixx
Well-Known Member
I'd rather suspect something to be wrong with the sensor... how could only one cylinder differ that much from the rest with one carb?
stixx
Well-Known Member
Damn.. PRH beat me to it.
512Stroker
We are all here because we are not all there.
I agree
I used the term " advanced" as stated by the OP not to confuse him.
As the OP did not install the cam he needs to verify that it was degreed correctly as it could be part of his power issue. I am not trying to sidetrack the thread, when I first read it I thought it a possibility that the cam has been installed incorrectly. Food for thought
I think it is more of an air flow issue as many have stated.
I'm out, please carry on.
TT5.9mag
Two atmospheres are better than one
It’s quite common on single plane single carb stuff. That’s why companies like Wilson Manifolds find so much power in professional level porting and modifying on intakes. Lots of guys stagger the jetting to compensate. @mbaird how did the plug look on number 7? That’ll tell you if it was a sensor issue.
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