just want some reassurance on combo choices

About 20 HP more only the Lunati 50156 Vs Isky & Crower.

Power Hit down low in street trim.
Not worth it I say the idle tuning tradeoffs.
 
The Lunati 50156 makes more Hp than the Crower & Isky.

But it has alot more Overlap.
Calculates to 17 degrees at .050" lift.
Crower & Isky are at 5 degrees @.050".

Its deceiving how much cam overlap is there because we are used to Advertised Overlap talking about cams.
Lunati lists the 50156 as Rough idle when I looked it up.

I tried to find a conversion formula for .050" to Advertised cam overlap.
It does not exist.

Intake Centerline is 104.

Its a Max effort EFI cam for drag race to me.

Not one I would choose for your Camaro because goals changed to ease of driving and tuning with EFI Edelbrock Pro Flow.
I noticed it was agressive. That's why I was curious to see what you thought about it. It is listed as an EFI grind, but I was thinking it would be borderline.
 
Yes a wider LCA/LSA will get better vacuum, but that does not answer the question WHY EFI
needs a higher vacuum than a carburetor.
The self learning ecu can't distinguish and learn the curves as accurately with cams with tighter lobes due to more overlap. More overlap leads to more unburnt fuel escaping. That leads to the ECU thinking it's richer than it is based on reading from o2 sensor and the self learning ecu has trouble learning to the curves is my understanding. You can use agressive cams with some of the fast systems. Not sure about the pro Flo 3 though. Brian can probably shed a more complete explanation. I'm just learning these issues as I read random stuff. Feel free to correct me if I'm wrong.
 
I thought you could go in and change the tables manually. I guess it's the self learning aspect that
can't cope with an erratic vacuum signal.

I guess EFI is borderline for me then.

Thanks for the info Christopher!!!
 
I thought you could go in and change the tables manually. I guess it's the self learning aspect that
can't cope with an erratic vacuum signal.

I guess EFI is borderline for me then.

Thanks for the info Christopher!!!
Holley and Accel have the most advanced Hotrod EFI Systems.
Cost alot more.
FAST Is of the Past now. Some use yet. Dated.

Most advanced by Far is Electromotive.
 
Yes a wider LCA/LSA will get better vacuum, but that does not answer the question WHY EFI
needs a higher vacuum than a carburetor.
Everything you think you know about Cams For Carburators you throw out the window for EFI.
The Chevrolet Corvette 1985 with its Tuned port 350 engine changed all.
The Very 1st successful powerful EFI Tuned port engine ever.
Worked so well 150 mph Top speed claimed in the Race car world.....all others were slow yet.
 
I noticed it was agressive. That's why I was curious to see what you thought about it. It is listed as an EFI grind, but I was thinking it would be borderline.
I tried to use a ratio formula of my own to determine Advertised valve overlap of the Lunati 50156.
Used the Isky RR272/282 as baseline since advertised and .050" valve overlap is known, 53 degrees advertised & 5.5 degrees @.050.
I came up with 163 degrees valve overlap.
Can not be right.

230/240 @050" cams can have overlap all over the place.
Most Famous of all is the Factory 1969 - 1970 RAIV 400 Cam with 87 degrees overlap.

In F.A.S.T> Drag Racing this RAIV 400 Engine is pretty much King.
Engine has to be 100 % stock.
No aftermarket cams .
No aftermarket cylinder heads.
No porting.
Just long tube headers.
No slicks or drag radials allowed.
Must use exact same tires the car was built with.
Bias Ply tires.
Radial Tires came out in 1973 on the Trans Am.

430-475 Hp obtained from the Pontiac RAIV 400.
Guys are Ripping Low 11's & high 10's 1/4 mile.

So we are not that far off with your 400 Small Block Chevy.
 
Have to check out Grumpys own Crane Cam in his 1985 Corvette.
He has used many.
Have to back to the early years on his forum when he was posting alone.
He ran some with 100 degrees Advertised overlap.
 
Have to check out Grumpys own Crane Cam in his 1985 Corvette.
He has used many.
Have to back to the early years on his forum when he was posting alone.
He ran some with 100 degrees Advertised overlap.
Curious to see those. How in the world could they run? I was browsing at some of the setup tables. It lists a few base tunes with vacuum reads from 5-12".... I may just try it with a cam that is on the milder side, but one that accomplishes my goals. If it doesn't work I will pull it off. Heck I have two other intakes, and a few carbs sitting around. It may turn into an experiment
 
yeah, I grew up with crane cams being 20 minutes from where I lived for 3 decades

https://cranecams.com/our-history/

94649615.RcAHIh9g.jpg

Inventory-L1H.jpg
 
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Maybe I will just run it on the test stand for a bit before actually putting it in the car. I really like putting fresh ones in the car and driving them and seating the rings, but I suppose I could achieve that on the stand.
 
ntRcn8Y.png


Grumpys own 1985 Corvette Cam.
Crane HR 230.
He has Trickflow Twisted Wedge Generation 2 cylinder heads made for just 2-3 years only. Good heads and very rare now.
383 sbc.
See how this cam works in a 400 sbc.
 
BG1b4P9.png


400 SBC.
Crane HR 230.
1.6 : 1 Ratio Rocker Arms.
Single Plane Intake.
Small Tube Headers open exhaust.

6NMrVDF.png


Same but with Dual Plane intake manifold.

ASoDKW2.png


True street trim.
Mufflers installed.

CgGV3xC.png


Street Trim Graph View.
 
Ok.
Power is very Good also with the Crane HR230.
Less Cam Overlap @.050" = 10 degrees.
Less than the Lunati 50156 = 17 degrees.
 
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