cam selection

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boilermaster

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Looking for some camshaft suggestions for my 351 C4v.

Engine is a factory rebuild of some sort, compression = 155-160 across the board and leakdown is in the 10 % range

4v heads with dot (assuming open chamber ) by 2E25 date code , but not 100% sure.

750 Holley vac.secondary's and unknown headers but in very good shape.

Has Holley street dominator manifold (single plane ) and Mallory unilite distributor.

I measured the cam's lobe lift at the pushrod and came up with .248''

that would equate to stock 2V lift specs, and who knows , may also have retarded cam timing.

18'' of engine vacuum at 16 degrees of initial would substantiate my 2V cam conclusion.

been looking at Sealed power CS650 and some kind of substitute for the D1ZZ-6250BX.

Found Lunati-10321001 at Summit racing but I am not sure if that is a direct replacement.

anyone care to make any suggestions based on my limited specs. ?

Boilermaster

 

basstrix

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4v heads with a 4* don't necessarily mean an open chamber head. The only way to know for sure is to either pull the intake and use a mirror to check the casting number or pull the heads. I suppose a 3rd way would be to CC the cylinder at BDC and TDC but that's getting a little elaborate. D1AE-GA heads are 4v closed chamber with the dot.

The compression numbers you're reporting are fairly high for an open chamber/stock piston setup. I am thinking it's more likely you have close chamber heads.

As far as cam grind goes, you really want to know what you have for heads (compression) and then read this article paying particular attention to dynamic compression: http://pantera.infopop.cc/eve/forums/a/tpc/f/5650045562/m/319104265

There's a chart which lists the static CR vs the dynamic CR vs Intake valve timing (valve closing). Select this aspect of your cam based on this chart and your engine's static compression ratio.

Also, the Wallace Racing calculators are handy for obtaining some of the numbers you may want to compare when selecting your cam: http://www.wallaceracing.com/Calculators.htm

The above assumes you want to run on pump gas and avoid detonation.

 

barnett468

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what is your gear ratio?

what trans?

what tires?

do you want bottom or top end power?

smooth, moderate or rough idle?

lite to lite drag car or freewy flier?

 

KT-69

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I stay close to old grind specs for the Boss 351 hydraulic version D1ZZ-6250-BX you mentioned.... Or a similar Comp Cam split duration grind. That is for a street motor with 3.25 gears, 4 speed top loader or C6/FMX auto with high stall CJ torque converter. Ford knew how make these 4V heads work on the street.

290°/290° duration @ 0.004"

0.505"/0.505" lift

Exhaust valve opens at 84° BBDC

Intake valve closes at 74° ABDC

62° overlap

219°/219° duration @ 0.050"

114° lobe separation angle

Intake lobe centerline = 109° ATDC

 

boilermaster

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4v heads with a 4* don't necessarily mean an open chamber head. The only way to know for sure is to either pull the intake and use a mirror to check the casting number or pull the heads. I suppose a 3rd way would be to CC the cylinder at BDC and TDC but that's getting a little elaborate. D1AE-GA heads are 4v closed chamber with the dot.

The compression numbers you're reporting are fairly high for an open chamber/stock piston setup. I am thinking it's more likely you have close chamber heads.

As far as cam grind goes, you really want to know what you have for heads (compression) and then read this article paying particular attention to dynamic compression: http://pantera.infopop.cc/eve/forums/a/tpc/f/5650045562/m/319104265

There's a chart which lists the static CR vs the dynamic CR vs Intake valve timing (valve closing). Select this aspect of your cam based on this chart and your engine's static compression ratio.

Also, the Wallace Racing calculators are handy for obtaining some of the numbers you may want to compare when selecting your cam: http://www.wallaceracing.com/Calculators.htm

The above assumes you want to run on pump gas and avoid detonation.
Basstrix,

Was thinking those numbers were a little on the high side as well,

Snap-on comp tester, known good numbers.

I am keeping in these things: factory rebuild will almost always have the deck and cylinder heads trued, what pistons were used and is the camshaft in there now contributing to increased cranking compression.

Since intake manifold will come off for cam change, I will get a chance

to get a look at the casting numbers on the heads.

Was also going to replace valve seals while checking valve springs.

wonder if one could get a good enough look at the combustion chamber thru an intake port with a valve open (with proper precautions) to determine piston usage and open or closed chamber, just a thought.

Barnett468,

3L91 gears, a little steep for my taste, possibly changing to 3L50, supposedly professionally rebuilt C4 transmission, 2800 rpm converter, magnum 500 14'' wheels will be needing new tires.

I do not want this to be a drag car, but have at least be at the power level of my previous 4V engines I have built

KT69, been on the Pantera website quite a bit for reference, that is where I came up with my part numbers, wish I would have been a good note taker in my younger days.

For now, I am leaning towards a copy of the D1ZZ-6250-BX if I find closed chambers and copy of D1ZZ-6250-A or B if I find open chambers.

Looks as I will have to determine for myself if I get a copy of the CJ camshaft , if it is early or late valve timing as I cannot get verification

from SEALED POWER (CS650) , HOWARDS CAMS (237211-15) or LUNATI (10321004) of their valve timing events.

any additional info or suggestions would be greatly appreciated.

Boilermaster


Also,

I am seeing that Comp Cams makes a flat tappet hydraulic lifter with a diameter listed at .875'' as opposed to the advertised OEM diameter of .874''.

My 1972 shop manual lists standard diameter as 0.8740''- 0.8745'' with a clearance to tappet bore of 0.0007'' to 0.0027'' and a wear limit of 0.005''.

Thinking of the additional .001'' tappet diameter as (oil control loss prevention ) as well as these lifters have a patented metered oil orifice to the pushrod and rocker.

looking at comp cams #832-16 on Summit racing site.

anyone ever use these and care to share results ?

Boilermaster

 
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Don C

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I agree with the others, your compression numbers are likely too high for stock open chambers. You may have either CC heads or domed pistons from the previous rebuild. Also, seems a little odd that a single plane manifold would be placed on an engine with a mild cam. I agree with your comment about the 3.91 gears with a non-overdrive transmission. I have 3.73 and while fun around town or on windy roads it's not great on the open highway. 3.50 sounds like a good compromise.

I don't believe you'll be able to get a look at your pistons through the intake runners and past the valves. An inspection camera is probably the best way. Harbor Freight has them fairly reasonable. I have one of these and it works pretty well, better than I expected:

http://www.harborfreight.com/digital-inspection-camera-61839.html

When you get a look at your casting numbers take a look here:

http://www.7173mustangs.com/thread-casting-numbers-and-engine-codes

If yours isn't listed or you see a discrepancy please let me know.

You can also play around with compression numbers in the spreadsheet at:

http://www.7173mustangs.com/thread-engine-and-compression-calculations

Get a rough idea of what your compression ratio is:

http://www.7173mustangs.com/thread-compression-altitude-calculations

 

boilermaster

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I agree with the others, your compression numbers are likely too high for stock open chambers. You may have either CC heads or domed pistons from the previous rebuild. Also, seems a little odd that a single plane manifold would be placed on an engine with a mild cam. I agree with your comment about the 3.91 gears with a non-overdrive transmission. I have 3.73 and while fun around town or on windy roads it's not great on the open highway. 3.50 sounds like a good compromise.

I don't believe you'll be able to get a look at your pistons through the intake runners and past the valves. An inspection camera is probably the best way. Harbor Freight has them fairly reasonable. I have one of these and it works pretty well, better than I expected:

http://www.harborfreight.com/digital-inspection-camera-61839.html

When you get a look at your casting numbers take a look here:

http://www.7173mustangs.com/thread-casting-numbers-and-engine-codes

If yours isn't listed or you see a discrepancy please let me know.

You can also play around with compression numbers in the spreadsheet at:

http://www.7173mustangs.com/thread-engine-and-compression-calculations

Get a rough idea of what your compression ratio is:

http://www.7173mustangs.com/thread-compression-altitude-calculations
Don C,

got off my butt and removed intake, took more time to clean off the grit around the ports and vacuum it up than it did to actually remove the intake itself.

The casting numbers D1ZE- DA with a born on date of 2E25 should make them open chamber.

suspecting now some block clean up and or head clean up.

Who knows what pistons are being used ?

Good thing is CLEAN but with that Holley street dominator, what a port mismatch , I believe it when they state that this manifolds ports are smaller than 2V.

That manifold will be on the must sell list.

Machine work and stock length pushrods may explain why there was so much lifter preload. (averaged 1-3/4 turns.

Now that I have it this far, might as well pull the front cover and radiator, will be time to order up parts on Monday.

Boilermaster

 

Don C

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Agreed on the open chambers, with that date code I was sure they were, the casting number verifies it.

Good luck on your build, keep us informed as to your progress, always interesting as well as educational.

 

basstrix

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I don't believe you'll be able to get a look at your pistons through the intake runners and past the valves. An inspection camera is probably the best way. Harbor Freight has them fairly reasonable. I have one of these and it works pretty well, better than I expected:

http://www.harborfreight.com/digital-inspection-camera-61839.html
I thought of the bore scope option after I posted. I bought one similar to this last year when I needed to inspect the cylinders on an outboard I rebuilt. It's small enough to fit through the spark plug holes and has a mirror allowing you to see the combustion chamber. I spent ~$40 on the one I bought because it didn't come with the mirrors.

http://www.amazon.com/Waterproof-Borescope-Endoscope-Inspection-Camera/dp/B013FXLXIQ/ref=sr_1_13?s=photo&ie=UTF8&qid=1451238692&sr=1-13&keywords=7mm+USB+Flexible+Inspection+Camera

I believe this is the same as the one I bought...it's a little more expensive than the one linked above: http://www.amazon.com/Supereyes-Inspection-Microscope-Endoscope-Borescope/dp/B007ROP3FO/ref=pd_cp_421_2?ie=UTF8&refRID=0K5ZQS3G4ARQSC8A94N1

THe nice thing with this is that you can use your laptop's screen....I've used the cheapo with tiny display and found many more benefits to the USB/Laptop style. Of course, the downside is, you have to have a laptop to use it.

 
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KT-69

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For the 4V Cleveland you have to verify what head piston combo you have as maximizing compression is an absolute must do. Back in the day first thing to do to a post 71 351 Cleveland was to pull the open chamber heads and swap for a set of 4V 70/71 closed chamber heads with the thin gasket to overcome the anemic compression ratio Ford bestowed on post 71 Cleveland's. Anything else you do will be minimized until you verify you have achieved 9.5:1 - 10:1 compression ratio. To little and you will not achieve the torque required for this combo to take advantage of the head design and required ignition timing. To much and you risk detonation or retarded timing to compensate.

Those of us who experienced 11.5 to 12:1 compression ratio and leaded gas know how much compression effects the seat of your pants and how an engine can pull throughout the power band.

3.25 rear gears with larger diameter tires than the OEM 25.9" will be about right for overall city/highway driving with only a 3 speed auto transmission. Tire wheel combo's in the 27-28" diameter range you could perhaps go with a 3.5:1 rear gear. I ran 3.79:1 and 3.90:1 back in the day with 26.6" diameter tires which were great for cruising the local strip or loop and stop light drag racing...top end speed burst max'd out (wrapped out) around 100 mph. Cruising the interstate at 55-60 mph and 3,500 rpm was a real drag and totally sucked. With those steeper gears I ran a BOSS 351 or Torker intake dual point distributor and 700- 750 Holley carb. One could purchase BOSS components over the counter back in the day. I also owned a white BOSS 351 from 74-77.....bought it used for $4K one hell of a muscle car!!!! I put Keystone wheels on it..air shocks, traction bars and N50's on the back for rubber. I will forever love a BOSS 351, Top Loader, Hurst shifter and ZZ-Top. Spent the rest of my life trying to recapture a bit of that magic ya just don't know what you got till its gone.

 

Luke

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650 and a dual plane would make it happier straight up

 

boilermaster

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Well,

I decided to pull the cam and see what I could see.

Dis assembly went well, intake valley nice and clean, pulled the timing cover and saw a double roller timing set with very little play and that's where it went south, when I removed the thrust plate I could see babbet, cam came out with no struggle, but the front cam bearing is wiped out, cannot see if any others are bad, guess she is coming out.

in my disgust, I removed the cylinder heads and have just the short block sitting there.

On the plus side, the combustion chambers seem happy and am looking at flat top pistons.

will measure the deck clearance tomorrow.

as I lowered the headers out from under the car I also noticed 2V headers on a 4V engine NOT GOOD.

Guess for now a teardown inspection is in order (concerned about main and rod bearings and oil pump.

SOOO why failed cam bearing (s) ?

I am thinking either poor remanufacture (perhaps did not lap in cam bearings)?

I was under the assumption that once a block was (seasoned) that

if the cam bearings were lapped in that one should be golden , and the block should not shift further ?

Going to see if the dealership I used to work for still has the cam bearing remover/installer and try to decide what type of cam bearings

I should install.

Will also take a further look at oiling system modifications seeing the crankshaft will be out soon.

Going to have to make a NEW parts list.

Anyone want to take a gander of why cam bearings failed ?

Boilermaster

 

basstrix

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I'm not familiar with lapping in cam bearings, so not sure about that. Unless there's damage (a crack, severe overheating, etc), the block should be stable.

Before you knock the old bearings out, look at the depth of each one (paying particular attention to #1) and also the clocking of the oil holes relative to those in the block. You'll want to find the root cause for the failure and a misaligned bearing is a good reason. Also look for signs that the bearing spun (this would be catastrophic and I doubt this happened). You'll need to check the alignment of cam bearing oil holes with the block on an engine stand with the crank and mains removed.

Your inspection of oil system mods may glean some info as well.

How many miles does this engine have on it?

 

c9zx

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Well,

I decided to pull the cam and see what I could see.

Dis assembly went well, intake valley nice and clean, pulled the timing cover and saw a double roller timing set with very little play and that's where it went south, when I removed the thrust plate I could see babbet, cam came out with no struggle, but the front cam bearing is wiped out, cannot see if any others are bad, guess she is coming out.

in my disgust, I removed the cylinder heads and have just the short block sitting there.

On the plus side, the combustion chambers seem happy and am looking at flat top pistons.

will measure the deck clearance tomorrow.

as I lowered the headers out from under the car I also noticed 2V headers on a 4V engine NOT GOOD.

Guess for now a teardown inspection is in order (concerned about main and rod bearings and oil pump.

SOOO why failed cam bearing (s) ?

I am thinking either poor remanufacture (perhaps did not lap in cam bearings)?

I was under the assumption that once a block was (seasoned) that

if the cam bearings were lapped in that one should be golden , and the block should not shift further ?

Going to see if the dealership I used to work for still has the cam bearing remover/installer and try to decide what type of cam bearings

I should install.

Will also take a further look at oiling system modifications seeing the crankshaft will be out soon.

Going to have to make a NEW parts list.

Anyone want to take a gander of why cam bearings failed ?

Boilermaster
My money is on incorrect installation (cocked in the bore). There is a discussion in the ford shop manual concerning the installation of the front cam bearing. Chuck

 

boilermaster

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Well,

I decided to pull the cam and see what I could see.

Dis assembly went well, intake valley nice and clean, pulled the timing cover and saw a double roller timing set with very little play and that's where it went south, when I removed the thrust plate I could see babbet, cam came out with no struggle, but the front cam bearing is wiped out, cannot see if any others are bad, guess she is coming out.

in my disgust, I removed the cylinder heads and have just the short block sitting there.

On the plus side, the combustion chambers seem happy and am looking at flat top pistons.

will measure the deck clearance tomorrow.

as I lowered the headers out from under the car I also noticed 2V headers on a 4V engine NOT GOOD.

Guess for now a teardown inspection is in order (concerned about main and rod bearings and oil pump.

SOOO why failed cam bearing (s) ?

I am thinking either poor remanufacture (perhaps did not lap in cam bearings)?

I was under the assumption that once a block was (seasoned) that

if the cam bearings were lapped in that one should be golden , and the block should not shift further ?

Going to see if the dealership I used to work for still has the cam bearing remover/installer and try to decide what type of cam bearings

I should install.

Will also take a further look at oiling system modifications seeing the crankshaft will be out soon.

Going to have to make a NEW parts list.

Anyone want to take a gander of why cam bearings failed ?

Boilermaster
My money is on incorrect installation (cocked in the bore). There is a discussion in the ford shop manual concerning the installation of the front cam bearing. Chuck
Well, Basstrix and C9TZ,

Called and talked to my machinist buddy this A.M. and he did give me some useful information as well as what you guys offer.

He likes to install the bearings dry from the rear to front and once the rear bearing is in place, gently install the cam with the remaining bearings still out and see if the camshaft is centered well with respects to how it looks at the front bearings bore.

if all looks good install the second bearing and turn by hand with cam gear attached, if all is good, proceed to the next, and so on it goes.

He states that this way one can at least tell at what location lies.

I do have a 1971 official ford shop manual.

I see that some bearings just have the oil hole and others have an elongated slot.

Saw some discussion on the net as to what the preferred clocking position should be with the slotted ones.

Will definitely pay particular attention to that installed depth of the front.

Buddy also states , remove crankshaft and reinstall main caps and torque to specs before removing or installing bearings.

Oh well, gotta finish removing engine today and get it on the engine stand.

this should also allow for a proper engine bay detailing while the engine is out.

Boilermaster

 
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I don't believe you'll be able to get a look at your pistons through the intake runners and past the valves. An inspection camera is probably the best way. Harbor Freight has them fairly reasonable. I have one of these and it works pretty well, better than I expected:

http://www.harborfreight.com/digital-inspection-camera-61839.html
I thought of the bore scope option after I posted. I bought one similar to this last year when I needed to inspect the cylinders on an outboard I rebuilt. It's small enough to fit through the spark plug holes and has a mirror allowing you to see the combustion chamber. I spent ~$40 on the one I bought because it didn't come with the mirrors.

http://www.amazon.com/Waterproof-Borescope-Endoscope-Inspection-Camera/dp/B013FXLXIQ/ref=sr_1_13?s=photo&ie=UTF8&qid=1451238692&sr=1-13&keywords=7mm+USB+Flexible+Inspection+Camera

I believe this is the same as the one I bought...it's a little more expensive than the one linked above: http://www.amazon.com/Supereyes-Inspection-Microscope-Endoscope-Borescope/dp/B007ROP3FO/ref=pd_cp_421_2?ie=UTF8&refRID=0K5ZQS3G4ARQSC8A94N1

THe nice thing with this is that you can use your laptop's screen....I've used the cheapo with tiny display and found many more benefits to the USB/Laptop style. Of course, the downside is, you have to have a laptop to use it.
You can use these cameras with your phone as well.

1971 M-code Mach 1

 

boilermaster

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Well c9zx,

You are indeed correct.

Front cam bearing is no where close to being in there square to it's

bore.

way closer at the bottom than at the top, thus all the wear at 6 O clock.

When I compared the top to bottom there was easily .020'' difference and even at the bottom, the bearing is nowhere close to the .003'' to .005'' spec.

My best guess is that all of the cam bearings were pulled in place from the front of the engine and therefore would have a difficult time with the tooling and trying to keep it square with so much tool hanging out the front.

Got the crankshaft out and the bearings look good (fully grooved mains) @ .010'' and rods the same.

Looks like the cylinder bore is +.020'' and deck clearance at TDC= .023''

Might as well measure cylinder head chamber volume tomorrow so I can get a more accurate compression ratio calculation.

Lots and lots of cleaning today mostly on the outside of the block and cleaning gasket surfaces and chasing threads.

don't see any sense in cleaning the block internals until I remove the cam bearings , will be looking for some cleaning brushes tomorrow as well.

That's all for today Boilermaster

 

basstrix

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Thanks for the update. Surprised the engine builder didn't catch the front bearing problem. Clevelands require special attention to the depth of #1...that and I would have expected the cam to bind and not rotate freely. The cam should turn freely without any tight spots. In the event the cam doesn't move freely, remove it, wipe lube off the bearings and inspect each bearing. There should be a burnished spot on the bearing(s) causing the problem.

 

c9zx

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The good news is given the +.020 bore and fully grooved main bearings, the previous builder was trying to do things properly. I know I sound like a broken record, assuming the readers know what a record is, using a very competent machine shop is a must. I hope the build goes well. Chuck

 
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