Changing Cam soon need setup advice...

[Crews69]

I recently purchased a custom cam from CamKing after learning that my cam was all wrong for my needs and combination of other parts. I am really excited to install the custom cam once it arrives but I don't want to screw anything up. I don't need any assistance installing the new cam but I am concerned that during the break in period I may run lean or damage something somewhere else. My car was tuned on a chassis dyno and runs great right now. All of he plugs are burning a nice mocha color and I'm not getting a lot of fuel smell at idle. My question is, how should I set the initial timing right when it starts. And should I change any jets before I start it with the new cam? Should I change the powervalve? Or make any other changes before firing up the motor. I purchased break in oil and CamKing gave me detailed instructions on the break in process. And also recommended the correct distributor gear material.
Here is some specs.
1969 Camaro SS X-11
Vehicle weight 3400lbs
383 stroker approx 2k miles on build using Amsoil 10w30 zrod high zinc
Block #14093638 1986-94 350
C053 on drivers side bell
5.7LG SGI on drivers bell
638 sides of block
14093638 Small Block V8 1987-1995 350, 4 bolt, roller or flat tappet cam, 1-piece rear seal
4.030 bore approximately 10.5.1 compression. Gauge says 190-200 on all cylinders
Scat forged 5.7” shot peened rods w/7/16” ARP bolts
1pc rms 5/64-5.7
Scat forged crank
Wiseco forged flat top pistons
fully balanced assembly with Scat flex plate and balancer included in balancing
hastings rings gapped at .018 lower .021 upper
King bearings checked and sized correctly
ARP 7/16" main bolts
S/A Gear adjustable full roller timing set advanced 4 degrees which brings center line of lobe to 104.5 Calls for 104 but this is the closest i could get it which brought (in opens BTDC to 17) not the recommended 19.

Lunati cam
00012 BM-II Hydraulic Flat tappet
RPM range 2500-6500
Lobe separation 108
rocker ratio 1.5
515 515 lift
246 246 duration
300 300 advertised

Custom ground cam by CamKing WHICH I AM GOING TO BE INSTALLING
Cam# SBCH, H71330-108
228/228 @.050"
.495"/.495" Valve Lift w/1.5 rockers
108 LSA

AFR Heads
210cc
67cc chambers Heart shaped
Stamped on end of heads
J 02
TYu
S 6
Stamped in valve train
.341 intake stem, 160r-c-wh
.341 exhaust stem, 1756-40100-208
Comp pro magnum roller rockers 1.5
Pro comp 7.8” pushrods
Viton stem seals
Starting spark plugs autolite 3922
Currently using autolite 3923
Quick Fuel 735 SS approx 8" of vacuum at 900rpm air bleeds drilled. Unknown jet sizes as it was tuned on a chassis dyno and I wasn't given those details.
MSD billet dizzy w/initial set at 18 and 33 with mechanical. Vac adv. unplugged and capped during timing process. After setting this I then plug the vac. Adv. to full manifold vacuum port on base of carb. I currently get just over 8" of vacuum at idle and I'm using a 4.0 power valve.
CamKing said I would likely see upwards of 14" of vacuum.

[jeff swisher]

Run it for break-in as is .. make sure the carb is full of fuel.
Keep a water hose or water sprayer handy to spray the radiator down if temps get too high.

You would need to be really lean to hurt things during break-in because you are not under load.
I do not think you will have any issues.

You can stop break-in if anything arises and just begin where you left off.

[Crews69]

Run it for break-in as is .. make sure the carb is full of fuel.
Keep a water hose or water sprayer handy to spray the radiator down if temps get too high.

You would need to be really lean to hurt things during break-in because you are not under load.
I do not think you will have any issues.

You can stop break-in if anything arises and just begin where you left off.

That's great thanks for replying. What would you expect to see as far as adjustments with this cam versus the old one? Less initial timing... maybe smaller jets... or more total timing. I'm curious where I need to focus on to fine tune. I don't want to spend another 500 on a dyno. If I can just get it really close then I'm happy.

[MadBill]

My S.W.A.G. would be: possibly a couple of degrees less total timing and slight possible reduction in jet size, but likely very close to right as is. Certainly close enough to be no worries but a short dyno check is always good insurance, more re power potential than a 'safe' tune

Would love to hear what if anything needs changing if you do dyno.

[jeff swisher]

I drive my vehicles and after break-in I set out on a cruise and see what kind of timing it likes best.
I will also jet down until i get a slight lean surge or lean feeling when tipping in slightly on the throttle.. Then jet up until all those shenanigans are gone and then go .001" or .002" larger on primary jet diameter or primary rod gets to go thinner in cruise mode if using a carb with metering rods.

That will almost always put the cruise in the 14-14.7 area.

Then I check and see how full throttle shift recovery is.. does it nose over on the shift then recover.. if yes then it is too lean.
I jet accordingly.. at the track I can jet for MPH.

You may look around your area for someone with a wheel dyno.. sometimes they have a dyno day that you can get a couple passes on the cheap.

Abel Racing here near OKC has a wheel dyno and Wednesdays are the day.
It is 50 now for 3 pulls and you get AFR readout.
I get idle and part throttle cruise at whatever rpm I need and I get wide open throttle.. of course I can change things between pulls like jetting or timing etc.

I just slapped together a deal and did not really tune it last week for myself as a daily driver.
750 edelbrock carb on a ported iron intake 385" sbc 13.8 part throttle cruise 13.7 wide open throttle. I changed rear jet and got 13.0 wide open.
50 bucks.

ask around at your local speed shops and see if you can find a wheel dyno place.

[Crews69]

My S.W.A.G. would be: possibly a couple of degrees less total timing and slight possible reduction in jet size, but likely very close to right as is. Certainly close enough to be no worries but a short dyno check is always good insurance, more re power potential than a 'safe' tune

Would love to hear what if anything needs changing if you do dyno.

Alright so you think I should set the total timing with vac. Adv. unplugged at 31? Which would bring the initial to 16.
And just leave the adj. vac adv can alone.
Then possibly jet down slightly. But how will I know if I need to do that?
Also, should I adjust the idle mixture screws at all?
And what about the power valve? It's a 4.0 right now because I could only get 8" of vacuum with this cam. But CamKing thinks I should see around 14" with his cam. I could put the 6.5 I still have back in easily enough.

[Crews69]

I drive my vehicles and after break-in I set out on a cruise and see what kind of timing it likes best.
I will also jet down until i get a slight lean surge or lean feeling when tipping in slightly on the throttle.. Then jet up until all those shenanigans are gone and then go .001" or .002" larger on primary jet diameter or primary rod gets to go thinner in cruise mode if using a carb with metering rods.

I seem to be feeling that slight surge feeling at cruise. Maybe 3500 rpm at 70mph. They said I was slightly lean in that area. Like a 16 I think they said. So with this new cam how do you think it will behave without changing the jets. Wiill this cam make that condition worsen?
That will almost always put the cruise in the 14-14.7 area.

Then I check and see how full throttle shift recovery is.. does it nose over on the shift then recover.. if yes then it is too lean.

I do not have that problem at all. It seems to run great. Just choppy at anything under 2200 rpm which is why I'm unhappy. Besides the fact that my wife's minivan makes more power to the wheels haha.

I jet accordingly.. at the track I can jet for MPH.

You may look around your area for someone with a wheel dyno.. sometimes they have a dyno day that you can get a couple passes on the cheap.

Abel Racing here near OKC has a wheel dyno and Wednesdays are the day.
It is 50 now for 3 pulls and you get AFR readout.
I get idle and part throttle cruise at whatever rpm I need and I get wide open throttle.. of course I can change things between pulls like jetting or timing etc.

I just slapped together a deal and did not really tune it last week for myself as a daily driver.
750 edelbrock carb on a ported iron intake 385" sbc 13.8 part throttle cruise 13.7 wide open throttle. I changed rear jet and got 13.0 wide open.
50 bucks.

Yeah I am going to see if Lucas English racing has a dyno day. A few years ago I had them tune my raptor 700 with a bunch of modifications. They mostly do turbo builds but they did a great job on my NA quad. I'm just not sure how good they are with carbs. It's almost a lost art. And a lot of old timers don't have the patience to teach the younger generation.

ask around at your local speed shops and see if you can find a wheel dyno place.

[jeff swisher]

Less reversion can pull harder on the carb making it act different .. leave it alone for now.
210cc heads might be fine for building the most power but not ideal for cruising at 2200 rpm. Smaller cam should help some.

I usually build with modified gm iron heads. I have ran 252@ .050 on a 106LSA solid flat tappet with a 355" and it was a pussy cat pulled 11.5" vacuum at 1000 rpm power brakes worked and it made me feel I needed a larger cam. But the heads were ported iron with 175cc runners.
That (small runners) takes a lot of the choppieness out of one.
I have ran the comp magnum 292H hydraulic (244 @.050)with the same build and it had 12.5" vacuum at 1000 rpm and it was even milder. Both pulled past 7000 RPM easy. those were both 10.3-10.4 compression
I ran a 252@ .050 hydraulic and it was in a 355 with low compression (9.0)(76CC chambers) and 210cc Those were AFR heads .. It had 5" vacuum.
It liked a lot of timing 42 total on 91 octane.

Run whatcha got for now and tune it as you get it on the road.
All engines act different and NO way you could guess at what jetting it will ultimately like. That takes drive time.

You know the carb works fine..so do not open it up before the cam is broke in..as you could screw something up and have it way whacked out.

Small piece of gasket debris gets into one of the small passages.. You never know what "Murphy" will toss at you when you are trying to do something good.

[MadBill]

My S.W.A.G. would be: possibly a couple of degrees less total timing and slight possible reduction in jet size, but likely very close to right as is. Certainly close enough to be no worries but a short dyno check is always good insurance, more re power potential than a 'safe' tune

Would love to hear what if anything needs changing if you do dyno.

Alright so you think I should set the total timing with vac. Adv. unplugged at 31? Which would bring the initial to 16.
And just leave the adj. vac adv can alone.
Then possibly jet down slightly. But how will I know if I need to do that?
Also, should I adjust the idle mixture screws at all?
And what about the power valve? It's a 4.0 right now because I could only get 8" of vacuum with this cam. But CamKing thinks I should see around 14" with his cam. I could put the 6.5 I still have back in easily enough.

<EDIT> Written before seeing above post.

There's a lot more to it than I can write here (and many carb guys that know far more and who may weigh in) but if the car was properly dyno-tuned as-is and runs well:

o I'd adjust the idle mixture screws for highest RPM, alternating with dialing the idle speed down to maybe 100 RPM more than the minimum stable idle. (I like to set it so I can hold an automatic in gear on the brake, give it a tap of throttle and have it return to idle without stalling.)
o Unless you can dyno it or tune by quarter mile speeds, I'd leave spark and jetting alone unless you detect significant symptoms like knocking or surging.
o I'd definitely go higher on the P.V. spec. The 'half the idle vacuum' is a widely quoted but bogus rule of thumb. A car tuned to a good lean cruise AFR will 'sag' on tip-in from steady speed with a low number valve like your present one. As it happens, in this case If you get the projected 14" of idle vac. the 'half' rule could be OK. A 6.5" PV is very common, but if you do dial in a lean (say ~ 15:1 or so) cruise*, an 8.5" might be a better choice.
o * A little time on a chassis dyno capable of steady-state testing can easily pay for itself in a single season's fuel savings.

[Crews69]

Less reversion can pull harder on the carb making it act different .. leave it alone for now.
210cc heads might be fine for building the most power but not ideal for cruising at 2200 rpm. Smaller cam should help some.
Yeah everyone keeps telling me my heads are too big for a street car application. They were already on the motor when I purchased it so they were all I had. It would be sweet if I could find someone to trade some of the smaller AFR 195's.
With a smaller cam it will "help" but how exactly? It seems like what these heads need is a big giant cam. I am an expert at building bridges and dams, high rise buildings etc. but I'm still learning the best combinations for engine building.

I usually build with modified gm iron heads. I have ran 252@ .050 on a 106LSA solid flat tappet with a 355" and it was a pussy cat pulled 11.5" vacuum at 1000 rpm power brakes worked and it made me feel I needed a larger cam. But the heads were ported iron with 175cc runners.
That (small runners) takes a lot of the choppieness out of one.

I purchased an entire willwood brake system. The biggest and best that they offer. But I was only making 8" of vacuum so I had to stick with a manual setup. With this new cam I'm hoping to be able to run a booster and get some power on these brakes. Unfortunately my willwood master cylinder is a 15/16" bore which does not work with a booster. So I will need to swap that out.

I have ran the comp magnum 292H hydraulic (244 @.050)with the same build and it had 12.5" vacuum at 1000 rpm and it was even milder. Both pulled past 7000 RPM easy. those were both 10.3-10.4 compression
I ran a 252@ .050 hydraulic and it was in a 355 with low compression (9.0)(76CC chambers) and 210cc Those were AFR heads .. It had 5" vacuum.
It liked a lot of timing 42 total on 91 octane.

See I'm wondering if I am going to take initial out of it. Like down to 16 initial. Then shouldn't I need to change the bushings in the dizzy to allow me to reach 36 total? Everyone always says 36 is the optimal total timing figure.

Run whatcha got for now and tune it as you get it on the road.
All engines act different and NO way you could guess at what jetting it will ultimately like. That takes drive time.

You know the carb works fine..so do not open it up before the cam is broke in..as you could screw something up and have it way whacked out.

Small piece of gasket debris gets into one of the small passages.. You never know what "Murphy" will toss at you when you are trying to do something good.

[Crews69]

My S.W.A.G. would be: possibly a couple of degrees less total timing and slight possible reduction in jet size, but likely very close to right as is. Certainly close enough to be no worries but a short dyno check is always good insurance, more re power potential than a 'safe' tune

Would love to hear what if anything needs changing if you do dyno.

Alright so you think I should set the total timing with vac. Adv. unplugged at 31? Which would bring the initial to 16.
And just leave the adj. vac adv can alone.
Then possibly jet down slightly. But how will I know if I need to do that?
Also, should I adjust the idle mixture screws at all?
And what about the power valve? It's a 4.0 right now because I could only get 8" of vacuum with this cam. But CamKing thinks I should see around 14" with his cam. I could put the 6.5 I still have back in easily enough.

<EDIT> Written before seeing above post.

There's a lot more to it than I can write here (and many carb guys that know far more and who may weigh in) but if the car was properly dyno-tuned as-is and runs well:

o I'd adjust the idle mixture screws for highest RPM, alternating with dialing the idle speed down to maybe 100 RPM more than the minimum stable idle. (I like to set it so I can hold an automatic in gear on the brake, give it a tap of throttle and have it return to idle without stalling.)
o Unless you can dyno it or tune by quarter mile speeds, I'd leave spark and jetting alone unless you detect significant symptoms like knocking or surging.
o I'd definitely go higher on the P.V. spec. The 'half the idle vacuum' is a widely quoted but bogus rule of thumb. A car tuned to a good lean cruise AFR will 'sag' on tip-in from steady speed with a low number valve like your present one. As it happens, in this case If you get the projected 14" of idle vac. the 'half' rule could be OK. A 6.5" PV is very common, but if you do dial in a lean (say ~ 15:1 or so) cruise*, an 8.5" might be a better choice.
o * A little time on a chassis dyno capable of steady-state testing can easily pay for itself in a single season's fuel savings.

I'm so upside down on this motor. Another dyno run is just gonna make it worse lol. I know your right though. It's good insurance. A friend of mine who happens to frequent this particular forum "rfoll" owns a gizmo that you screw into my 02 bung and will read my AF in real time. So that will certainly help me get the carb dialed in. Timing will be a different story though. I'm thinking that I will swap the cam, degree it according to camkings specs.
But let's move forward to the moment I start it. If I'm supposed to immediately raise the rpm to 2500 or so then how the hell am I supposed to set the timing? I will go ahead and swap the powervalve to the 6.5 I have on the shelf. So I shouldn't need to monkey around with the carb at this stage at all.
And another thing... I'm breaking this new cam in and all this metal is going to be flushing right through my main bearings. That can't be good. I have six quarts of Amsoil break in oil. And some new filters. I did not install a high volume oil pump as it is supposed to be hard on the distributor gear. It's just a standard volume Melling pump with the bypass oil filter adapter.

[Old as Dirt]

But let's move forward to the moment I start it. If I'm supposed to immediately raise the rpm to 2500 or so then how the hell am I supposed to set the timing?

By twisting the distributor and looking at the dampner with a timing light at 2500rpm..try it around 32* for starters.. idle timing will be what ever it is until you decide to change it.. if it pings under load when you drive it..
Reduce timing or buy better fuel..
If not.. try a hair more, keep in mind intake temps.. those AFR heads like those numbers with a good combustion chamber and a good exhaust port, should flow 290+cfm @ .600 lift.
For crying out loud, 10.5:1 SBC will usually run on goat piss with Aluminum heads..
Check for reference idle timing when you feel you have it running good..

You are going with a better for your Combo(milder flat hydraulic) because more than likely your combo doesn't include a high stall convertor and a good set of low gears, where the old cam needed more of both than what you have, no satisfaction and didn't perform to your expectations... just guessing here, but I think I am on the right track..
or Mike wouldn't have recommended it..
sounds more like sanitary hotrod daily driver, than a full on drag car.. which is my preference..
383
Trans?
Gear?
Header size?
What exactly do you expect from this Stroker 383 with the right cam..??..
Reality imho.. 395-410hp turning under 12.00 et at the track.. like 1.1hp / CI.. decent numbers for a driver.. anything more is icing on the cake.
Getting groceries, thumbs ups and lots of fun on a Saturday night cruise.. with decent fuel economy and a great torque curve.
Break it in and change the oil..
See what it does..
And run the "gizmo" in the exhaust so the jetting is around 14.8 - 15.00afr while cruising.. 12.0 under a hard WOT load until you read some plug chops.. play with heat ranges and carb air bleeds until you get back to your "mocha" colored plugs that make you feel happy... will probably last for a good while.

Or you could give 500 to the Dyno guy and not have to do the work...

[Crews69]

But let's move forward to the moment I start it. If I'm supposed to immediately raise the rpm to 2500 or so then how the hell am I supposed to set the timing?

By twisting the distributor and looking at the dampner with a timing light at 2500rpm..try it around 32* for starters.. idle timing will be what ever it is until you decide to change it.. if it pings under load when you drive it..
Reduce timing or buy better fuel..

Alright that makes sense... so I'm not concerned with getting the timing perfect right away. Just into a safe condition. Then commence with the break in procedure and dial it in later.

If not.. try a hair more, keep in mind intake temps.. those AFR heads like those numbers with a good combustion chamber and a good exhaust port, should flow 290+cfm @ .600 lift.
For crying out loud, 10.5:1 SBC will usually run on goat piss with Aluminum heads..
Check for reference idle timing when you feel you have it running good..

You are going with a better for your Combo(milder flat hydraulic) because more than likely your combo doesn't include a high stall convertor and a good set of low gears, where the old cam needed more of both than what you have, no satisfaction and didn't perform to your expectations... just guessing here, but I think I am on the right track..
or Mike wouldn't have recommended it..
sounds more like sanitary hotrod daily driver, than a full on drag car.. which is my preference..
383
Trans? TCI th400 with a bnm hole shot 2400 stall. My original cam was a 2500-6500. So I bought a converter that came on at 2400. I thought I just needed to match those numbers
Gear? 4:11 rearend.
Header size? Dougs 1 3/4" primaries 3" collector and 2.5" stainless with X pipe and magnaflows
What exactly do you expect from this Stroker 383 with the right cam..??.. it's running pretty damn good right now. But choppy below 2500 rpm. This is solely a street hot rod. No strip. I want to drive it with my wife and cruise down the highways comfortably. But have some muscle behind it. I built this motor myself and it came with those heads and cam. I should have replaced them with something different but my goal is an LS platform. This small block is just temporary. Maybe another five years and I'll build the permanent power plant.
Reality imho.. 395-410hp turning under 12.00 et at the track.. like 1.1hp / CI.. decent numbers for a driver.. anything more is icing on the cake.
Getting groceries, thumbs ups and lots of fun on a Saturday night cruise.. with decent fuel economy and a great torque curve. Yes that's exactly what I'm hoping for. But my combination only made 300hp 350tq on a chassis dyno. I know they are just numbers but geez my wife's minivan pulls that much haha
Break it in and change the oil..
See what it does..
And run the "gizmo" in the exhaust so the jetting is around 14.8 - 15.00afr while cruising.. 12.0 under a hard WOT load until you read some plug chops.. play with heat ranges and carb air bleeds until you get back to your "mocha" colored plugs that make you feel happy... will probably last for a good while.

Will do! Thank you very much for the advice. And hope your enjoying this awesome weather we're finally getting in the PNW!

Or you could give 500 to the Dyno guy and not have to do the work...

[Old as Dirt]

Turbo 400's eat HP, but are pretty tough.. the Cam from Mike will really help with the low stall convertor and the gearing.. bet it will run great and drive great.. Ya, killer weather..
Spent the weekend with the Grandkids riding quads @ Walker Valley ORV Park..

[Crews69]

Turbo 400's eat HP, but are pretty tough.. the Cam from Mike will really help with the low stall convertor and the gearing.. bet it will run great and drive great.. Ya, killer weather..
Spent the weekend with the Grandkids riding quads @ Walker Valley ORV Park..

Awesome!!! I've never been to Walker Valley. I ride the Oregon dunes primarily. Winchester bay, coos bay etc. once in a while I throw the dirt tires on and ride Jones creek washougal. If youve never been there try to make a point of going someday. It's about a 20 mile loop through the forest on groomed trails. Lots of fun stuff built into the trail.

I always make the mistake of going to big. The th400 was another one of those mistakes haha. I mean it shifts awesome and is supposedly good for 1200 horse. And the price was only a couple hundred more than the 350. So I figured why not.
I thought about using it behind an LS3 and installing a gearvendors unit.
Have you built an LS based engine yet? I'm trying to talk my engine building mentor rfoll into it but he's pretty anti LS haha. I think he's just afraid he will like it to much and want to sell his dart 400 drag motor setup that he sunk a bunch of money into hahahaha But to me this is what it's all about. The fun of just building cool stuff. It's like therapy for me. All alone with my own thoughts and whatever I'm working on. Good times.