I have a few cam questions for an upcoming build that I'd like to have some help on gathering alternate resorces, & feedback on some of your previous experiences.

First, here is what I have:

 63 F100 Stake bed that has a 292 mated to a cruise O that I rebult around 12 years ago. The goods inside her are:  .060 with standard rebuild pistons, etc.  Isky e-4, cite heads homebrew port & pollish, with 1.78 intakes, 9425 intake, home made 4 into one mid length headers, 65 reman Autolite 4100 1.08 with a (my specialty) ported secondary venturi & throttle shafts slimmed. 

I last year added 1.6:1 rocker assemblies from Rocker arm specialists that are fabulous!  It actually sounds more like it has an aftermarket cam now, not to mention the nice torque gain with my .438 total valve lift with the E-4 isky & lash being considered.

I should probably leave it alone, but as many of you probably feel, why the heck not define it to what you really want? Right?

I should also mention that after the dana 44 recently had bearing issues I accidentally found a dana 60-2 from a 64 f100.  The difference for those of you who weren't aware of the 60-2 like I previously was is it is a dana 60 that is not a full floater, with 5 on 5 studs & identical brakes to that of a dana 44.  In doing this swap I went from 3.73's that were in the old dana 44, to 4:10 limited slip in my big hunk of indistructible dana 60-2. 

My plans are to do the t-5 swap asap, as freeway driving here in Denver leaves me winding up to around 3800, 4000 to keep with traffic. 

Now for the cam talk:

I have ECZ-G's that I plan on have Mummert do his street port with 1.94, 1.60's.  I am also considering biting the bullet & re-rebuilding the whole thing & getting the dome pistons he has to up the compression to allow me to use a more aggressive cam.  I want to go fast & want it to sound mean @ the cruise nights!

I have considered all of the other Isky offerings, but am indiferent to the low lift figures.  I Like the lift figures of some of the Erson offerings, but have one grind in particular that I want to have custom ground by them.  It is their TQ 30.

The specs are: TQ 30: Advertised, or lash Duration 280, Duration @ .050 230, lobe Lift .310, Theoretic valve lift with 1.60:1 rockers .496, valve lift considering lash .476.

When I talked with Erson, the guy was unfamiliar with y blocks. (suprise surprise)  He did however say for that kind of duration in a 5k or so truck that I should have a min. of 10:1 compression to get the cylinder pressures up to make it work.  He said if I sent him flow figures for the heads, including static compression estimates that he could further help to see if this grind would work. 

 Has anyone ever tried a cam like this?  What combo of components worked or didn't?  Has anyone ever tried a 230° Duration cam@ .050 in a truck?  

Any help would be appreciated.  Sorry for the long post..

63 Red Stake 

Welcome to the site!  Always great to have new members coming on board.

Likely the greatest concern with using popup pistons is ending up with a compression ratio that will not tolerate pump fuel.  Because the camshaft is a player with this, there is not a set in stone rule for the static compression ratio in regards to octane fuel requirements as the dynamic compression ratio would over-ride this.  Generally, I like to keep the dynamic compression ratio at 8.5:1 or less for a street engine so the engine will at least tolerate 92-93 octane pump fuel with an optimal ignition curve.

The other concern would be with your proposed camshaft selection being used in conjunction with the stock converter.  Manifold vacuum would be reduced just enough that the engine would struggle to idle in gear while maintaining a neutral idle that was not excessively high.  Part of this can be overcome by advancing the camshaft and/or increasing the valve lash setting.  Of course, any kind of increased stall in the converter would give more latitude in this area.

Some rudimentary math on your existing combination and some assumptions towards your deck clearance (0.000”) and combustion chamber cc’s (77), I calculate an 8.2:1 static compression ratio for your existing combination.  With the E-4 camshaft installed 4° advanced and the valves set at 0.018” lash, the dynamic compression ratio is 6.9:1 which will allow the engine to run safely on 87 (or less) octane fuel.  If the camshaft was installed straight up (108° intake lobe centerline), then the engine is even more low octane fuel tolerant but cranking compression will be reduced and so will be the low end torque.

Throwing this same math at your new proposed combination with popup pistons (10cc dome), G heads that are unmilled at 69cc’s, and the TQ-30 camshaft installed at 4° advanced (assuming the camshaft is ground on 110° lobe centers), I get an intake valve that closes at 66° ABDC which equates to a dynamic compression ratio of 7.9:1 which is in theory mid grade fuel tolerant and workable for your combination.

Your plans sound like a lot of extra expense for a 5k truck (or car).  Dont get me wrong because 5000 rpm is fine for me too.  If you arent careful you will build a nice motor for the tracks, that will be a pain in the ass on the streets.

Likely your quench now is a lot more than the 0.00 of Ted's assumption for the static and dynamic compression calculation, meaning even less on the compression stats.  Think what your motor might be capable of if it has the static compression called for by the E-4 of 9.5:1? 

The short block I just completed has an E-4, with static compression of VERY close to 9:1, and dynamic of 8.1:1.  It should  run great within the parameters of my driving habits and needs, and the cam ceiling of 5k.

I know for sure the block was never decked.  So I am sure my Dynamic figures are low.  I am swapping to a t-5 mustang tranny, so that should take care of converter issues.

My E-4 is intalled Straight up, & also since I built this thing while in High School, used the stock silent chain that came with the kit.. Who knows how far behind the cam is!  I probably don't have 20k on this engine, so I would be happy to swap the heads, & put a cam in that allows more of a street rod sound, without altering the current 5k too much & be pleased as punch!

I have been teasing the Idea of applying the dramatic imballances of the dual profile "Thumper" Cams that comp makes.   One possible problem here is that I know they are retro fit roller cams, so I know ramp angles are not remotely compatable.

But lets just say that I took the Erson Tq30M, or even the Fiflow IIM, & merged it with something like My E4.  Could it work??  It looks to me like the exhaust duration will be that of the larger cam. But the exhaust lift would be slightly less than that of a typicall cam lobe with that same duration.  Then it appears as though the intake would be alot milder duration, with a slightly taller lift..  The "Thumper" cams are also ground on 107 lc.  The rpm bands are mild when you consider the idle sounds they produce.

The combo I thought would be great: An Erson Tq20 & Tq 30 combo:

Intake:.220@.050  Lift of .544(1.6 rockers)

EXhaust: .242@ .050  Lift of .496(1.6 rockers)                

In therory, if the valve train doesn't hand gernade, the rpm range should be around 2300-5800.  Quite streetable, & should be tolerant of mid grade fuel.  The Idle should be nice & rough!  Am I Crazy?  Or could a cam be ground to produce the best of both worlds for our Y blocks?  I Personally don't think I will be reving my engine 6k, so don't want to have to build an engine that tollerates that in order to get the sound. I could almost live with what I have now if it sounded the way it does on a cold day, cold start!

The Guy @ Comp said he could grind this for me, & it would be as close to a thumpr as he could get.  No lifters, just cam.  The guy means buisiness when he "cuts & pastes", so I highlighted stuff to make the partial words make more sense.

            SPEC CARD
PART #: 37-000-5       ENGINE:  FY   FORD 292-312 Y BLOCK SPECIAL CAM
RINDING INSTRUCTIONS 1
""         ""       2
""         ""       3
GRIND #: FY 6017 /6068  S 107.0
SPC INST 1:
SPC INST 2:
J. DIAM: STD       INT     EXH
ALVE ADJUSTMENT   .016    .016
ROSS VALVE LIFT   .500    .513
URATION @    .015
    TAPPET LIFT   270    276
ALVE TIMING     OPEN   CLOSE
@ .050    INT    10     34
           EXH    51      7
PECS FOR CAM INST. @ 102.0 CENTERLINE
                    INT     EXH
URATION @  .050    224.00   239.00
      LOBE LIFT     .313    .321
LOBE SEPARATION 107.0    FIRING ORDER  STD
OCKER ARM RATIO     1.60   1.60  REQ SHIP DATE          (MMDDCCYY)

Any of the experienced guys, feel free to jump right in... I could be hitting page two by myself!!!, or with I If necessary!

Kevin

Non-symetrical or dual pattern camshafts are used when there is a large disparity in the ratio of intake to exhaust port air flows.  If the intake port is too large or the exhaust flow is inadequate, you’ll find a larger exhaust duration than what is being used for the intake.  It’s actually more complex than this but this is the simple explanation.  For the most part, the Y-Blocks are content with symetrical grinds where the intake and exhaust durations on the camshaft are the same.  In my own case where the exhaust is extremely efficient and scavenges very well, then the exhaust duration is actually smaller than the intake.  If just wanting a rumpy idle, then just reducing the camshafts lobe centerline will accomplish this.  The 107° lobe centers you’re talking about will give you that desired rumpy idle without having to resort to an abnormal increase in exhaust lobe duration.

Kevin

Over scavenging creates a situation where too much of the incoming fuel mixture goes out the exhaust in lieu of going into the cylinder which hurts fuel efficiency, overall performance, and can permit the exhaust to run much hotter than normal.

Increasing the exhaust duration forces the exhaust valve to close later after TDC and in turn increases the valve overlap for the exhaust valve closing and intake valve opening.  By using a dual pattern camshaft that has more exhaust duration than the intake, the exhaust is open (at overlap) for more degrees past TDC than the intake is open before TDC which makes it ideal for exhaust head flows or exhaust systems that are inefficient.  Increased overlap can be beneficial for high rpm performance applications but causes some inefficiencies at the lower rpms usually in the form of fuel dilution and/or excess fuel mixture going out the exhaust by lieu of the intake and exhaust valves both being open simultaneously.  With this then is a power band that has been shifted to a higher rpm and in turn leaves the engine with less low end torque or being more sluggish on the bottom end.  As the exhaust duration is increased, a reduction in manifold vacuum is created as the open exhaust valve ultimately becomes a vacuum leak for the cylinder for as long as the exhaust valve is open after TDC.  There is a point for a given combination up to where overlap is beneficial but anything beyond this threshold has the power band shifting radically and becoming exponentially more negative in regards to low end performance.

Because of the myriad of engine combinations and resultant exhaust systems to go with these, there are a multitude of camshaft grinds to cover all the different options.  The key here is to pick the camshaft that fits your driving style along with the engine/chassis combination.  I’m all too familiar with instances where dead stock camshafts would easily outperform a performance grind only because the performance grind was not suited for the combination in which it was installed.

Anyone else can jump in at any time to add to this.  This is a grey area and open to interpolation from different points of view.

I guess my dumb logic is:

Camshaft "A"     Intake:  230 duration @.050, .500 lift @ valve

                     Exhaust: 230 duration @.050, .500 lift @ valve

107 degree lobe centers, installed straight up. 

Camshaft "B":     Intake:  220 duration @.050, .500 lift @ valve

                     Exhaust: 220 duration @.050, .500 lift @ valve

107 degree lobe centers, installed straight up.

Shouldn't camshaft "A" have more of a midrange powerband, with strong torque?

Shouldn't camshaft "B" have more of a flat torque curve, with a later, or higher rpm powerband.

If I was a person who had a powerband in mind that was in between these, instead of picking the cams that propotiionatly are in between, wouldn't a combination of these two lobes in one cam have a mixture of both attributes, a midrange cam with a flatter torque curve?

Kevin

As Paul mentioned, it's the total combination that must be taken into consideration when selecting a camshaft.  At best, any given camshaft is a compromise as for those areas in the rpm range where something is gained, there are other areas where something is lost.  This is where degreeing in the camshafts becomes a valuable tool as camshafts that are not an exact fit for a combination can be 'dialed' in for increased performance in the desired operating range.

Increasing the lobe centerline would create a flatter torque curve.  Increasing the duration raises the powerband.  Where both camshafts have the same lobe centerline, camshaft B would have an rpm opertating range that is lower than that of camshaft A with camshaft B having increased manifold vacuum at idle and better idling characteristics.

I talked to my guy @ Erson last night & he ran a bunch of numbers, including my "wanna be" cam that comp proposed. 

I gave him the flow specs from Mummert's street port 1.94/1.60 ecz-g chart.  He actually proposed a grind that is a dual pattern, but with slightly more duration & valve lift on the intake side.  He said it should build real strong torque, & with the lobe separation should have the idle I am looking for. 

The questionS I have for you guys is this: with the cam specs that I paste below, will my valve to piston clearance be ok?

Do you agree that this would be a nice small step up from my current e-4/cite combo?

I think I remember that it IS possible to change the lifters from the bottom.. Can anyone confirm?   I have no problem pulling & putting it on a stand to use gravity & pull the pan,just need comfirmation.

Thanks,

Kevn

Erson custom gind:

The headers I have are very close to the stubbies that red's sells.  Mine have initial primaries that are also 1 1/2, after about 6 to 8 inches, they become 1 3/4. 

I built them using a pipe bender, a set of flanges, & a used set of 4 into 1 headers from a full size wagoneer.

How big a cam did you use??

You have talked to a cam grinder who has been in business for nearly half a century, gave him your parameters, and he computer designed a cam specifically for your application.  Then you ask if any of us have any experience with such a cam.  Well, he designed it for you, how could we have any experience with it.  I say go with what he says.  It's his business.  He wants you to be happy with it.  Just my opinion.

John

I agree with John.Stick with what the cam grinder advised . I was so poor when I was a kid ,I had to pull the choke out and pretend I had a BIG cam ???.The black smoke gave it away when I drove away ??? It sounded pretty tough .

Regards Lon

The .469 net intake valve lift is expected to get you by without having to notch the pistons but I’d recommend checking just in case your rocker ratio is varying.  At least 0.075” clearance is the universally accepted mininum clearance value where the intake valve is involved.

Lifters can be installed with the engine in the vehicle.  Ford had a special service tool for this.  Turning the engine upside down definitely eases some of the pain though.

John, Ease up there friend.  I wasn't asking anyone if they had ever tried the specific cam I posted specs for...

I was curious if anyone had tried a similar dual pattern cam(s), & their results, or opinions.

I agree with your very valid point about the cam grinder & their computer designed setup being the way to go.  I do however value the collective opinions of the guys who have skinned their own knuckles, & mixed their blood with the y-block both currently & in years past. 

Knowledge & wisdom is what I am here for.  I don't mean to offend anyone by my curiosity, or questions that may seem elementary, or neive to you or anyone else. 

If the popularity of this great engine is going to continue to boom, passing the torch with speed secrets & tips is in my opinion a win win for everyone.  The more demand for these engines, the more the aftermarket will take interest.

Just my opinion- which again is not ment to offend or incriminate anyone.

I appreciate your wisdom guys, really.

Kevin

I'm sorry if I came off as trying to slam a door in your face.  What I was trying to say is something I've preached for a long time, and that is to listen to your favorite cam grinder.  All of us old farts grew up buying off the shelf cams from Isky, Crane, Engle, Herbert, Clay Smith, Crower, etc, and that's all we had available.  Present cam technology far outstrips anything available back in the '60s and 70s, and can be far better matched to what you are doing.  Dual pattern cams started to surface right after the popularity of the Y Block started fading, so they didn't get a chance to be tested.  And I still stand by my advice for you, listen to what Erson tells you.

John

No problem.  Just here to enjoy the y block & it's fans. Sorry if I caused a comotion.

Does anyone know for sure if lifters can be changed in-chassis?

Thanks,

Kevin

I changed the lifters in the chassis once, a long time ago.  My brother-in-law worked at a Ford dealer at the time, borrowed the tools to do it.  It was very time consuming and aggravating, and when I got finished I took it for a test run  and found I had dislodged the rear cam plug and it came out while driving.  So I ended up pulling the engine anyway.  I have since always pulled the engine and turned it over like Ted said. 

John 

Kevin

If you are going for a lumpy idle and sound, I suggest you go to the Y Block event in Columbus 8-31/9-2, and listen to some of the cars there.  I personally would build for performance, not sound.  I have seen many cars that are over cammed and over carbureted get blown away by milder set ups.  Hopefully you can find what your looking for and have your cake and eat it too.  I have a 91 Mustang with a supercharger that has straight cut gears in it.  If I had heard one before I bought it, I would have made a different selection.  It really performs well, and when I pull into a drive in on a cruise night everyone looks, but I don't appreciate the whine.  Now the young guys say is sounds "Sweet" ( I guess that used to be Cool), but the whining sound of the gears  reminds me of the late 40's early 50's Pontiac and Buick 3 speed sticks with straight cut gears, the old timers will know what I'm talking about.  I am going to try to make the event this year myself.

Good Luck, 

I wish I could make it!  That will be a goal for next year.  Maybe I can ever get my beast road worthy for a long trip by then.  I think that the performance is my main priority, I just have the gears & std. trans combo going in that make me more tolerant of a bit of a hotrod idle.

Doug, I already asked on the other topic, but I am curious what was suggested for your truck cam wise?

Kevin