Symptoms of wrong cam installation

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My brother doesnt work on a lot of stuff himself. One reason is he works 7 days a week and has a ton of irons in the fire. I know i dont. I pay to get heads ported, and my engines assembled, because there are people around way better at it than me. I spec everything out, then enjoy seeing if it performs the way i envision it will. Its worked out really well doing it that way over the years. That said, i have popped enough heads off, pulled enough trannies, lashed enough valves, etc, etc, etc, to be semi dangerous taking care of my stuff…lol
Not all of us have your skillset, or even care one way or the other if we do.
There is absolutely nothing wrong with that. Everybody has different things they are good at. I am just happy to be able to spend time with him at the track once in a while, neither of us will be around forever
Try not to be so judgemental about what reasons people have for how and why they do things. He has skills i doubt very highly you have. Everybody is different.


Waiting 13 months to have an engine built when I was 20 changed my mindset. And the only reason it wasn’t longer was I told him to keep the engine when it was finished. I would sacrifice the 600.00 which was big money back then to make a point. What really cooked my goose was my cousin (a dirt track racer) was having issues and I told him about “Bill”. Well guess what “Bill” built an engine for him, before mine was done. I lost a good friend that day but I got the books out and started reading. I’m not what you would call a smart man but I was smart enough not to put up with that crap. I became the go to guy for degreeing in cams for friends and people in town and never charged a cent. I hate second guessing and it would kill me to not know why an engine wasn’t running as it should.
 
Waiting 13 months to have an engine built when I was 20 changed my mindset. And the only reason it wasn’t longer was I told him to keep the engine when it was finished. I would sacrifice the 600.00 which was big money back then to make a point. What really cooked my goose was my cousin (a dirt track racer) was having issues and I told him about “Bill”. Well guess what “Bill” built an engine for him, before mine was done. I lost a good friend that day but I got the books out and started reading. I’m not what you would call a smart man but I was smart enough not to put up with that crap. I became the go to guy for degreeing in cams for friends and people in town and never charged a cent. I hate second guessing and it would kill me to not know why an engine wasn’t running as it should.

agree completely
 
B3,
Post #49.
Nope.
Advanced will reduce choppiness because you are trapping more air with the earlier closing of the intake valve...& making for better combustion.
Engine vacuum is an indicator of idle quality & combustion efficiency. You get a smooth idle with 18" of vac, rough-er idle with 10".
 
Ok, so I have a question about degreeing the cam. My 360 is not running right, and I have come to the conclusion that the cam is probably retarded. It idles ok, but it seems like it is just not making any power. The car has 4.10 gears but will not spin the tires. Period. If I open the throttle in park, it will rev up, but it is slow to respond, and always smells rich, even with the idle mixture screws leaned out. I have an MSD 6 plus and MSD billet distributor in it, I have played with the timing, both retarding and advancing, and while it clearly prefers advance, it is still a complete dog. I ran a near identical setup in my last Dart, and it was a screamer, even with 3.23 gears and stock Mopar electronic ignition.
Any thoughts or suggestions are welcome, I installed the cam "straight up" at least according to the marks on the timing gears.
Thanks
 
Ok, so I have a question about degreeing the cam. My 360 is not running right, and I have come to the conclusion that the cam is probably retarded. It idles ok, but it seems like it is just not making any power. The car has 4.10 gears but will not spin the tires. Period. If I open the throttle in park, it will rev up, but it is slow to respond, and always smells rich, even with the idle mixture screws leaned out. I have an MSD 6 plus and MSD billet distributor in it, I have played with the timing, both retarding and advancing, and while it clearly prefers advance, it is still a complete dog. I ran a near identical setup in my last Dart, and it was a screamer, even with 3.23 gears and stock Mopar electronic ignition.
Any thoughts or suggestions are welcome, I installed the cam "straight up" at least according to the marks on the timing gears.
Thanks
I will have to look up the cam specs and post them later, can't remember off the top of my head and I'm on my way to work.
 
Ok, so I have a question about degreeing the cam. My 360 is not running right, and I have come to the conclusion that the cam is probably retarded. It idles ok, but it seems like it is just not making any power. The car has 4.10 gears but will not spin the tires. Period. If I open the throttle in park, it will rev up, but it is slow to respond, and always smells rich, even with the idle mixture screws leaned out. I have an MSD 6 plus and MSD billet distributor in it, I have played with the timing, both retarding and advancing, and while it clearly prefers advance, it is still a complete dog. I ran a near identical setup in my last Dart, and it was a screamer, even with 3.23 gears and stock Mopar electronic ignition.
Any thoughts or suggestions are welcome, I installed the cam "straight up" at least according to the marks on the timing gears.
Thanks


See post 7. Doing that will at least tell you if the cam is actually retarded. It won’t tell you how much, but you can clearly see if it is.
 
Specs as follows:
Adv exh dur 298
Adv int dur 288
Exh dur @ .050 224
Exh lift .466
Int dur @ .050 214
Int lift .444
LSA 112
Will check valves at overlap too.
 
That is a very common cam, sold by a few companies. I would doubt that installing it in a retarded position would kill the low end performance because of the low duration/low overlap. It should have lots of tq to spin wheels with 4.10 gears. You may have a faulty cam, ground incorrectly; or valves not seating because lifter pre-load adjustment is bottomed out. There are quite a few possible causes.
 
B3,
Post #49.
Nope.
Advanced will reduce choppiness because you are trapping more air with the earlier closing of the intake valve...& making for better combustion.
Engine vacuum is an indicator of idle quality & combustion efficiency. You get a smooth idle with 18" of vac, rough-er idle with 10".

Yup told him twice. Twice he argued, do screw it.
 
If the cranking compression numbers look good, and the leak down numbers are good as well....... I’d say a trip to the chassis dyno would be the next step.
See what the power curve looks like, and what the power numbers actually are........ along with seeing what the carb is doing with the A/F ratios.
 
If the cranking compression numbers look good, and the leak down numbers are good as well....... I’d say a trip to the chassis dyno would be the next step.
See what the power curve looks like, and what the power numbers actually are........ along with seeing what the carb is doing with the A/F ratios.
IMO the 950 carb/single plane has very poor booster signal down low. My 340 runs better with a smaller venturi.
 
IMO the 950 carb/single plane has very poor booster signal down low. My 340 runs better with a smaller venturi.

i ran a 950 on my 360 with low compression and that same cam. Ran excellent.
Generally a 950 is same venturi as a 750.
I ran a 950 on my 318 too. It loved it a tenth better than it did a 750
 
All “950’s” are not created equal.
In other words...... there are several “sizes” of 950’s.
For off the shelf “950’s” the Venturi sizing can be 1.375, or 1.450, or 1.600.
All are called a “950”.

When discussing carbs these days, especially 950’s...... it’s usually best to be talking in terms of Venturi size and throttle bore diameter.

My 20 or so year old “built from scratch” “950”(actually flows about 860 calculated wet flow), using a genuine Holley HP950 body that has the 1.375” Venturi, which is the same size as the typical 750 DP.

1A4409FE-74C8-4CBF-92E7-B7A2CF4ACB00.jpeg


Getting off topic I know......

When the Proform bodies came out, I built several new carbs around those. I used new Holley 4779 metering blocks, and those things ran very well.
A few years ago I built one from the Holley version of that body, and outfitted it with some “bling”(billet baseplate and metering blocks).
I have yet to try it on something, so I don’t know if it’s good, or if it’s a flop.
It’s basically an HP750....... 1.375v/1.687bore

AA7AFB5A-EC28-464B-9D03-6DB64BC7EE23.jpeg


With what the Brawler carbs sell for nowadays, it doesn’t pay to build your own from scratch.
 
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All “950’s” are not created equal.
In other words...... there are several “sizes” of 950’s.
For off the shelf “950’s” the Venturi sizing can be 1.375, or 1.450, or 1.600.
All are called a “950”.

When discussing carbs these days, especially 950’s...... it’s usually best to be talking in terms of Venturi size and throttle bore diameter.

My 20 or so year old “built from scratch” using a genuine Holley HP950 body has the 1.375” Venturi, which is the same size as the typical 750 DP.

View attachment 1715783137


Good info. I know there were different sizes but never researched what they were. I did take a second to measure my custom made 1000 cfm APD alcohol carb that I bought earlier this year. Pretty sure it was made from a 950 so I will check and compare my numbers later today. Thanks.
 
If the cranking compression numbers look good, and the leak down numbers are good as well....... I’d say a trip to the chassis dyno would be the next step.
See what the power curve looks like, and what the power numbers actually are........ along with seeing what the carb is doing with the A/F ratios.
I agree
The cranking cylinder pressures will tell the story.
I asked for them back in post #3
Do the simple things first.
It's the old "KISS" theory
 
I passed along the info to my brother from this thread for what he needs to check, plenty of good info here.
It should be said that prior to the install of the eddies and “ new cam” along with the 8 inch vert, the car ran very respectable 12.70’s with just bolt ons, stock iron heads, and a small comp flat tappet cam, along with a 10 inch vert. Ran as good as it should have at that point.
The introduction of good heads( they were previously on a 408 that ran 10’s) the new vert and cam didnt do much of anything over how it ran before, which gave me the thought about the install of the new cam being wrong
 
The thing that really gets me about this post is the converter stall. It takes a lot to turn a 5000 stall converter into a 3200 stall converter. I’m not sure a slightly retarded cam can lower the stall that much. I would be slightly concerned about the converter itself.
 
The thing that really gets me about this post is the converter stall. It takes a lot to turn a 5000 stall converter into a 3200 stall converter. I’m not sure a slightly retarded cam can lower the stall that much. I would be slightly concerned about the converter itself.

Agreed, i called Jason about it, he pulled out his sheet from having built it, and was astonished it flashed so low.
My brother said on the street it felt way healthier, but at the track it just had zero low end power
 
It takes a lot to turn a 5000 stall converter into a 3200 stall converter.

I agree.
But..... sometimes not everyone is on the same page as far as how we are determining what the stall speed is.

One other thought on the converter thing.......
If the motor was “right” and the converter were just really tight...... the 1/4 mile speed should still look pretty good.

If the stall is way lower than expected, and the speed is also low........ that points more towards a low HP problem.
 
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I agree.
But..... sometimes not everyone is on the same page as far as how we are determining what the stall speed is.

One other thought on the converter thing.......
If the motor was “right” and the converter were just really tight...... the 1/4 mile speed should still look pretty good.

If the stall is way lower than expected, and the speed is also low........ that points more towards a low HP problem.

it flashes 3200.
 
With different posts I often repeat myself to often but October of last year I changed out a powerglide transmission and converter to test something. In my head I thought it was my old 5600 stall converter that I never got around to sending out to have checked when I put my new 5760 stall converter. Well my car was a Pig with the sixty foots slowing .06-.07 and slowing in the 1/8 from what should have been 6.01-6.03 to 6.32 and I couldn’t catch a light worth a damn. I ended up parking the car for the weekend. I just got that converter back and he said everything looked great inside. At that point I checked my RacePak info and it stalled at 4800 rpm last year. 1000 rpm worth of stall turned my car into a SLUG. Now I need another 5800 stall converter for a back up.
 
With different posts I often repeat myself to often but October of last year I changed out a powerglide transmission and converter to test something. In my head I thought it was my old 5600 stall converter that I never got around to sending out to have checked when I put my new 5760 stall converter. Well my car was a Pig with the sixty foots slowing .06-.07 and slowing in the 1/8 from what should have been 6.01-6.03 to 6.32 and I couldn’t catch a light worth a damn. I ended up parking the car for the weekend. I just got that converter back and he said everything looked great inside. At that point I checked my RacePak info and it stalled at 4800 rpm last year. 1000 rpm worth of stall turned my car into a SLUG. Now I need another 5800 stall converter for a back up.

yep. Convertor being right is huge. That is why the first call i made( for my brother) was to the guy who built the convertor.
It factually flashes 3200. I told the guy( myself) exactly what the combo was, and that i wanted it to flash 5k behind it.
I also know that convertor being correct is super important when you are dealing with a 3400 pound, low ish compression 340 with a very big camshaft.
My brother is just ultra busy all the time. We will ultimately get to the bottom of what is going on. When he finds time to spend on it
 
I agree.
But..... sometimes not everyone is on the same page as far as how we are determining what the stall speed is.

One other thought on the converter thing.......
If the motor was “right” and the converter were just really tight...... the 1/4 mile speed should still look pretty good.

If the stall is way lower than expected, and the speed is also low........ that points more towards a low HP problem.

the speed is low too. I know it didn't come close to 90 mph in the 1/8. Not looking at his slips, but if memory serves his best 60 foot was high 1.80’s..7.97 and 88 ish mph
I expected to see 7.55 ish at 92-93 minimally, even in the 3500 foot of air that day
 
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