[ericwoo]

Originally Posted by Formulas

To get a performance expectation based on reality search this site for info concerning your Crower camshaft in a 400 ( more popular build ) and adjust reported powerband RPMS by almost 500 more.... 350s of any brand really drop off in torque after idle with cams 20 degrees more than stock duration.. And because they are small engines to start with they are a bit handicapped to start with.

This is good to know. And yes I was thinking it was just a terrible camshaft selection in the 350 but now it makes me wonder if I have to remove the heads also if replacing the cam.

Originally Posted by Dragncar

The Perfomer was always considered a better intake than the RPM for a 350.

Makes sense. thanks

Originally Posted by Stan Weiss

Now that you have advanced the cam. Have you done a cranking compression test again? If so can you and tells what the numbers are now?

Stan

Yes, I just checked tonight after getting it nice and hot. The psi #'s were pretty high after advancing the cam with the below:

Driver Side:

• #1 : 207 psi
• #3 : 230 psi
• #5 : 207 psi
• #7 : 212 psi

Passenger Side:

• #2 : 220 psi
• #4 : 220 psi
• #6 : 222 psi
• #8 : 204 psi

Is that looking ok?

[Stan Weiss]

Originally Posted by ericwoo

This is good to know. And yes I was thinking it was just a terrible camshaft selection in the 350 but now it makes me wonder if I have to remove the heads also if replacing the cam.


Makes sense. thanks



Yes, I just checked tonight after getting it nice and hot. The psi #'s were pretty high after advancing the cam with the below:

Driver Side:

• #1 : 207 psi
• #3 : 230 psi
• #5 : 207 psi
• #7 : 212 psi

Passenger Side:

• #2 : 220 psi
• #4 : 220 psi
• #6 : 222 psi
• #8 : 204 psi

Is that looking ok?

Looking at those numbers I think the cam and its phasing are fine. What octane fuel are you running and what does you ignition timing curve look like?

Stan

[ericwoo]

Originally Posted by Stan Weiss

What octane fuel are you running and what does you ignition timing curve look like?

Stan

I've been putting in premium fuel which is usually 91 or 93. I thought Kauffman made it sound like they doubt I need it that high so occasionally put in mid grade 89 to test.

I've messed with timing settings dozens of times and nothing really improves performance significantly. Now timing is at about 15 degrees idle and goes up to around 32 degrees at 3,000 rpm.

I did recently adjust the carb mixture again with a richer mixture and seems to pick up a slight improvement. My guess is hp is on par to the 350 HO now which isnt too bad so I am not as disappointed as before but was really hoping to get at least a little more than that.

I'd guess the car probably does have around 320 horsepower like the HO but I have a very hard time seeing it have anywhere near 380 lb-ft of torque like the HO has.

The low end is what I would actually like to work on so I may order the Rhoads lifters that I recently learned about.


If I were to guess, I'd say this car might do around 14.5 secs in the quarter mile. I hope to test in a week or two and will report back.

Other than that, I am kinda hitting a wall with getting this 350 to excel better than the 350 HO. I am beginning to think that is the max possible performance and these engines really are duds

[Schurkey]

Originally Posted by ericwoo

Now timing is at about 15 degrees idle and goes up to around 32 degrees at 3,000 rpm.

And the vacuum advance adds how much at part-throttle?

Originally Posted by ericwoo

I did recently adjust the carb mixture again with a richer mixture and seems to pick up a slight improvement.

HOW are you adjusting the mixture?

I get the sense you're playing with the idle mixture screws, and expecting it to make some global improvement.

[Squidward]

Originally Posted by ericwoo

I've been putting in premium fuel which is usually 91 or 93. I thought Kauffman made it sound like they doubt I need it that high so occasionally put in mid grade 89 to test.

I've messed with timing settings dozens of times and nothing really improves performance significantly. Now timing is at about 15 degrees idle and goes up to around 32 degrees at 3,000 rpm.

I did recently adjust the carb mixture again with a richer mixture and seems to pick up a slight improvement. My guess is hp is on par to the 350 HO now which isnt too bad so I am not as disappointed as before but was really hoping to get at least a little more than that.

I'd guess the car probably does have around 320 horsepower like the HO but I have a very hard time seeing it have anywhere near 380 lb-ft of torque like the HO has.

The low end is what I would actually like to work on so I may order the Rhoads lifters that I recently learned about.


If I were to guess, I'd say this car might do around 14.5 secs in the quarter mile. I hope to test in a week or two and will report back.

Other than that, I am kinda hitting a wall with getting this 350 to excel better than the 350 HO. I am beginning to think that is the max possible performance and these engines really are duds

I am not a tuning guru by any stretch. I think you could get into the 13's with your setup, tho.

Still hoping you can find the performance you are looking for. Just got back from a drive in my bird, and the 350 runs hard. Keep at it!

I had the same question about your carb tuning. You are cammed up, and I can't imagine your idle vacuum is any better than 12-15" max. Hoping your power valve is matched. And your vacuum secondary out of the box settings likely don't match your engine. It has been years since I played with a Holley, so I will step aside on that adventure. Your timing sounds adequate.

[chiphead]

Originally Posted by Squidward

I am not a tuning guru by any stretch. I think you could get into the 13's with your setup, tho.

Still hoping you can find the performance you are looking for. Just got back from a drive in my bird, and the 350 runs hard. Keep at it!

I had the same question about your carb tuning. You are cammed up, and I can't imagine your idle vacuum is any better than 12-15" max. Hoping your power valve is matched. And your vacuum secondary out of the box settings likely don't match your engine. It has been years since I played with a Holley, so I will step aside on that adventure. Your timing sounds adequate.

I've asked questions about the carb tune before on this one. A 650 should support that engine to about 5400 or so. Shoot for about 67-69 jets primary, .055 PVCR depending on primary HSAB. Secondary should be adequate, it would be good to know what secondary plate is in this 4160.

Please let us know what vacuum secondary spring is currently installed? What is the list number from the airhorn?

Rhodes lifters could be a good option to tame the cam. The issue with those pumping numbers, you may have trouble managing pump fuel if you go with a smaller cam and standard lifters. Advancing the cam makes the intake closing point happen earlier so it builds cylinder pressure and moves RPM range down. If that's not enough to recover torque 2000-3500, you'll need the rhodes.

[Jay S]

The problem this will run into adding Rhoad’s lifters is the engine has a 2700 stall converter behind it, and original Rhoad’s and VPro both are both nearly pumped up by 2700. By 3500 they don’t gain any low end at all. They would gain a little bottom end at 2700, but not much. You would have to do a Vmax Rhoad’s and set the clearance higher to see much for low end power gains when the engine starts out at close to 3000 RPM, and even with a Vmax it won’t help that much at 2700, they are mostly pumped up, probably gain 20 lbs of tq at best. They would help drivability, if that was a concern. It doesn’t sound like that is a concern on this though.


There is still something wrong. I am not very surprised it is still struggling after the cam timing changing, 190 psi was enough before. A 350 can pump about 10 psi more than a 400 on the same octane. Probably even a little more, but even above 200 it could start having issues on anything less than 93 octane.

One thing obvious to most everyone that has chimed in, which have used stock 600 VAC Holley’s in the past ( I have done at least 10 of them), is that is a bottle neck for making much more than 300 HP. There could be multiple problems yet holding the combo back too, unknown problems in the short block, but that particular carb with no tuning is going to hinder any gains in performance in the future..

Could be the converter isn’t holding it either. The 200R4 should spin the tires hard coming out of first gear with its bigger ratio jump going into second. If it can’t do that, something could be wrong in the converter.

[ta man]

Originally Posted by Jay S

The problem this will run into adding Rhoad’s lifters is the engine has a 2700 stall converter behind it, and original Rhoad’s and VPro both are both nearly pumped up by 2700. By 3500 they don’t gain any low end at all. They would gain a little bottom end at 2700, but not much. You would have to do a Vmax Rhoad’s and set the clearance higher to see much for low end power gains when the engine starts out at close to 3000 RPM, and even with a Vmax it won’t help that much at 2700, they are mostly pumped up, probably gain 20 lbs of tq at best. They would help drivability, if that was a concern. It doesn’t sound like that is a concern on this though.


There is still something wrong. I am not very surprised it is still struggling after the cam timing changing, 190 psi was enough before. A 350 can pump about 10 psi more than a 400 on the same octane. Probably even a little more, but even above 200 it could start having issues on anything less than 93 octane.

One thing obvious to most everyone that has chimed in, which have used stock 600 VAC Holley’s in the past ( I have done at least 10 of them), is that is a bottle neck for making much more than 300 HP. There could be multiple problems yet holding the combo back too, unknown problems in the short block, but that particular carb with no tuning is going to hinder any gains in performance in the future..

Could be the converter isn’t holding it either. The 200R4 should spin the tires hard coming out of first gear with its bigger ratio jump going into second. If it can’t do that, something could be wrong in the converter.

I was going to respond as well with possible drive train issues..I've had bad transmissions that seem ok but have held power back. A fun day at the dragstrip would give us some data.

[Stan Weiss]

Originally Posted by ericwoo

I've been putting in premium fuel which is usually 91 or 93. I thought Kauffman made it sound like they doubt I need it that high so occasionally put in mid grade 89 to test.

I've messed with timing settings dozens of times and nothing really improves performance significantly. Now timing is at about 15 degrees idle and goes up to around 32 degrees at 3,000 rpm.

I did recently adjust the carb mixture again with a richer mixture and seems to pick up a slight improvement. My guess is hp is on par to the 350 HO now which isnt too bad so I am not as disappointed as before but was really hoping to get at least a little more than that.

I'd guess the car probably does have around 320 horsepower like the HO but I have a very hard time seeing it have anywhere near 380 lb-ft of torque like the HO has.

The low end is what I would actually like to work on so I may order the Rhoads lifters that I recently learned about.


If I were to guess, I'd say this car might do around 14.5 secs in the quarter mile. I hope to test in a week or two and will report back.

Other than that, I am kinda hitting a wall with getting this 350 to excel better than the 350 HO. I am beginning to think that is the max possible performance and these engines really are duds

I assume when you degree the cam you used a degree and found true TDC and zeroed everything. Have you done the same thing with your timing marks, made sure they show zero at true TDC?

Stan