Howards Camshafts (Summit)

I'd like to point out that cam manufacturer's descriptions of their camshaft's characteristics are notoriously inaccurate. This post of yours is from another topic:

quote:

Originally posted by Horace Cope:

... I have new Trickflow CNC heads fitted on my Pantera mated to a Holley Street Dominator manifold.

However I am a bit disappointed in the performance especially low down. Would you recommend the TFS track heat manifold and if not whats a good intake match.

Cam is Comp Hyd Roller .578 lift plus Holley Vac sec

Had this setup with my Aussie 2v quench heads and performance was impressive

Horace

The current camshaft is 290°/290°, 110° LSA, 70° overlap. That's a big cam to choose for somebody looking for performance "down low". Since you liked the performance of the engine with the Aussie 302C heads, the swap to Trick Flow heads and the choice of the big cam lead me to believe you're looking for higher output from your Pantera's engine, would that be accurate?

When you changed the heads, did you change any other parts simultaneously, or just the heads? By the way, which Holley carburetor did you purchase and install? Does the short block have dished pistons or flat tops?

Rather than comment on the quality of the Howard cam, if you don't mind I'd like to understand what performance and power band characteristics you are attempting to achieve. Could you also share with us what troubleshooting you have performed to the current set-up, if at all, in trying to understand why it doesn't perform to your satisfaction?

Hi George

Happy to answer your questions: I didn't make it clear that my old Aussie 2V setup I mention was on another Pantera I once owned. I wanted to try and replicate that.

This engine was in the car when bought, stock motor with 4V open chamber heads etc. Not a lot could be salvaged so it was stripped and totally rebuilt. Good thing was it was a 4 bolt main. Pistons were changed to +30 forged flat tops, TFS complete heads with 1.55 springs and 62cc chambers, Comp cam roller hyd kit as you mention. Harland Sharp roller rockers. Holley 600 vac sec with 70 primaries and secondary fuel block 72 secondaries. Following previous advice from you lifter galleries were bored and sleeved.

Only thing kept from the old engine was the Holley Street Dominator intake manifold and crank.

Performance of this engine is pretty impressive but the power band comes in much too late for me. Would like it to come in a lot earlier

My thinking is most of the setup is good but I may have gone for the wrong cam hence looking at a different spec cam. I am also not convinced by the single plane intake. The old Aussie 2V heads were mated with an Edelbrock performer 2v dual plane.

In summary: Current performance good but not good enough. Need the power band lower down.

Cheers

The video gives a good comparison between single plane and dual plane manifold performance. This helped me decide what was best for me on my car. Here is a direct link to the video below. Edelbrock Intake Manifold Dyno Test

Mike I am in full agreement regarding swapping the Holley manifold for the Performer 2V intake manifold.

For your application I am strongly opposed to any dual plane manifold with a cut down plenum divider, or a dual plane manifold used in conjunction with an open spacer below the carburetor. This is due to your expressed desire for improved low rpm performance. Like a single plane manifold those things negate the purpose of having "dual planes" in the first place ... i.e. extending the time between pulses within the intake manifold.

I also believe you need to reduce overlap. Since your Pantera's engine is already set-up for a hydraulic roller cam, I'd suggest swapping the Comp Cams camshaft for the smallest Crane Cams hydraulic roller (HR216). The only thing besides the cam that "may" need to be swapped is the distributor gear. The Crane camshaft is ground on a steel core and needs a steel distributor gear for compatibility.

quote:

Originally posted by Horace Cope:
Anybody used these Howards camshafts from Summit and can shed some light on their quality etc.

Have to admit I have not heard of them.

I have a Comp Cam roller hydraulic at present which I wish to change out, not giving the performance expected.

The spec and performance I am looking for seems to be provided by a Howard cam.

Cheers

Call up Bullet Cams, they are very nice, they could design one to your requirements.

Thanks for the info George and others, Edelbrock performer ordered and is on its way. No spacers or plenum dividers planned.

Another problem seems to have reared its head this last weekend. Car ticks over and is fine till about 2000 revs. After 2000 revs and up a loud tapping noise appears. Back off again below 2000 and it goes away again.

Sounds to me like the lifters maybe getting starved of oil somehow.

I am running Comp cam roller hyd, comp cam roller lifters, std oil pump, 10 qrt pan, lifter bores have been sleeved. 10w 40 semi synthetic oil.

I also run a capilliary oil guage. One thing that has been worrying me since the rebuild is that max oil pressure is never more than 50psi and less once oil is hot. Oil pump is new, do you think it could be faulty, new ARP oil pump drive fitted.

Any ideas George or anyone as to whats going on here.

Cheers

Horace, Have you done any of the oil system mods recommended? George Pence has a great tutorial about this.

I'm sorry you are having problems with the engine.

Tappet noise, noise in the valve train, etc. is usually the result of insufficient valve guide clearance. Other valve train noise can be caused by a faulty tappet having an excessive bleed-down rate, or a tappet that has come apart (the tappet internals have popped-out).

However, if the tapping you hear is not coming from the valve train, its usually a spun rod bearing. A spun rod bearing may contribute to low oil pressure as well.

On the subject of oil pressure, there is normally plenty of oil pressure with tappet bore bushings. Its hard to guess why it may be low, if its not related to a spun bearing. Since the pump has a "built-in" relief valve it is as likely a culprit as anything else. I always recommend disassembly of new pumps, cleaning them and inspecting them before installing them. Finding metal chips is common. A metal chip lodged into the relief valve, holding it partially open, is another possible cause of low oil pressure.

I suspect the roller rockers are tapping the inside of the valve cover.

JT that was the first thing I checked, no evidence or marks on either the rockers or the inside of the valve covers.

As mentioned the lifter bores were sleeved which is one of George's recommendations.

Lifter clearances (pre loads) were done in accordance with the manuals at the build stage, ie 3/4 turn etc. Roller hyd lifters.

If it was a spun bearing George why would it only happen above a certain revs, surely we would hear it from the start. Because its only happening over 2000 thats whats pointing me towards oil and pressure or lack of it etc.

Will have to pull the engine to look at possibly cleaning the oil pump. Thats the time to check the rod bearings also as you suggest.
Oh well another weekends work and another couple of hundred $s on gaskets coming up.

cheers

I have no experience with the Comp Cams hydraulic roller tappets, I don't know who makes them. I don't know how much compression Comp Cams suggests for adjustment. But 3/4 turns compression sounds like too much. 3/4 turn was fine 4 decades ago, but the plungers of modern hydraulic tappets are not capable of being compressed as much as they were 4 decades ago ... nor do they need to be compressed as much. Start with re-adjusting the tappets, in the car, with the engine warmed-up and running. Adjust them 1/4 turn beyond the point where they become silent.

Were the bearings recently replaced, or are they the old bearings? If they are the old bearings, they are worn, that would explain the low oil pressure.

George/guys

Pulled the engine today and the noisy tappet turned out to be a completely wiped out crank journal, see pictures below.

No 3 rod journal has been worn down completely, possibly in excess of 30 thou, not sure if this crank is saveable. However No 7 next to it is fine as is the other 6. Oil pressure was not great but never below 50 psi.

This was a brand new engine build, everything new, rods, bearings, ARP rod bolts,fresh oil, new HV oil pump, ARP main studs etc etc. Lifter bores sleeved, crank checked cleaned and passed by the engineering shop.

This engine has not done more than 20 miles since being built. Why would something as extreme as this happen in such a short time.

Main bearings are all good as is the other 7 rod bearings. Nothing left of No 3 rod bearing most of which is shrapnel in the sump.

Needing to take this back to the machine shop but any ideas ?? Got me absolutely stumped.

Cheers

More pics

and more

Mike,

Was the engine hard to turnover to start initially? The only suggestion I can come up with is the rod & cap were clamping the bearing on the journal and not clearance fitted. Might be an issue with one rod if these were new, have you checked dimensions?

Julian

Julian

No quite the opposite, it was quite free even turning over by hand.

Yes they were all new ARP rod bolts. Fitted by the engineering shop who assured me they were sized ????

For that much wear in such a short space of time its obviously seen very little oil but why. All the other rods and rod bearings are good ?

Mike

I'm quite sorry this happened.

Assuming all of the connecting rod big ends were properly resized after the rod bolts had been replaced, I would guess that the cap for that connecting rod was installed in the wrong orientation.

wow i had the same thing same journal on my first Cleveland, to this day I'm not sure what the cause was but it could've been i flipped a rod cap backwards

http://pantera.infopop.cc/eve/...0045562/m/5601027956

4V and proud

that link you refer to on the forum was a friends engine we were putting together not mine, totally different engine though the ARP rod bolts were fitted by the same machine shop.

The tightness in turning ended up being the crank journals not being machined out to the radius correctly. Funnily enough done by the owner at a previous machine shop.

Thanks George, Possibility I could have put a cap on backwards in the build assembly but we will never know now. Usually something I'm methodical on but we can all make mistakes, it could be something as simple as that.

All the parts will be back down at the machine shop today. I will update on their comments

Horace, cranks are successfully welded up and reground every day in many countries. A pro inspection by a shop specializing in crank repair may result in saving your beat up crank- stock or aftermarket. Then, a std. overhaul will get you back on the road. You may need a replacement rod, though, depending. Shipping 351-C cranks around is pricey since they weigh 54 lbs!

...Yes, We All make Mistakes! Part of Being Human. Here's what I Know:

After receiving a Set of Clevite 7 Rod Bearings, in the scope of 'Assume Nothing', I Inspected Each and Every Piece. I ordered the set in .010" Over, as the Crank had been Re-Ground/Polished .010 Under.
All Half Bearings were stamped .010, Excepting for ONE Single Half...was Stamped .020, ofcourse I sent the entire set back and then received back a complete and correct set. Is this what happened in Your case, as You pointed out, we'll Never know.

Next, Before Disassembly of the Rotating Assembly, it is Prudent to FIRST, before All, Stamp the Number of the Cylinder on all Rod Caps, Both Halves, Cap and Rod, 1 Thru 8, As they are Viewed When Rotating the Crank to Access. So with the Stamped Numbers, one would have to slip-up on the Details or be Distracted, in Order to Install the Cap Backwards. Without the Numbers on the Rods/Caps it would be Impossible to know Which Cylinder the Rod Goes To!? Unless one was very well organized and did the Rods One at a Time.

I concur with the Boss, Crank Journals are welded and reground Every Day! Just be sure to take it to an 'Experienced' Crank Shop of Experts.

"...When You Pay Peanuts...You End Up Hiring a Bunch of Monkeys!" (George Peppard-The A Team)

P.S. In My Opinion, 4-Bolt Mains with ARP STUDS is the Only way to Go. Maximum Rigidity! That's the Way I built My Shortblock. Even used ARP STUDS on the Heads, Especially.

The machine shop say they can save the crank by exactly that, welding up and re grinding back.

All the mains and the other 7 rod journals are fine so no need to weld them all up I feel. The crank was std before all this but with the amount of metal that came from the wiped out bearing/journal I think it wise to maybe do them all to -10 etc. My only concern is that they get it fully straight again and balanced.

First comment from the machine shop which I am not too enamoured with is that the no 3 cylinder must have hydrauliced somehow, the rod is so bent and twisted. Could fuel, water or oil cause a hydraulic lock and twist a rod that badly, I am not too convinced. There is no evidence in that piston or the heads, valves etc that bears this out. They reckon the rod has twisted and loaded and consequently wiped out that bearing and journal ???.

Marlin I agree. My engine has 4 bolt mains, ARP cap studs, ARP head studs and ARP rod bolts all new. The machine shop has the Clevite bearings so I will take a look at what is stamped on them next time I'm there. Unfortunately no chance of checking No 3 as it was thin as paper when we took it off so again we are unlikely to ever know.

Comments please guys on the hydraulicing issue above.

Cheers

quote:

hydraulicing issue?

...I Suggest, the Con Rod was already 'Slightly' Bent from the Beginning-Day 1. It was missed during Inspection and Assembly.
The Crank Journal and Wrist Pin Axises NOT Being in the Same PLANE cause a 'Twisting Force' upon every stroke. This Force is what Knocked-Out the Rod Bearing. When the Bearing Failed, the Rod was Twisted Even Further.

It's Called 'Hydraulic LOCK'. But what Fluid would have 'Leaked' into the Cylinder...And NOT leave any evidence?? Instead of Hyd-Lock, I can Imagine a Poorly-Timed 'Miss-Fire', or similar (Crossed Plug Wires Maybe) 'could' have bent a Rod. Do You Remember any such event?

Just Guessing Here, as In My Past, I have found a Bent Rod in a 400 Pontiac Engine I was Re-Building. NO Cause was ever found!

P.S. About those ARP HEAD Studs!! AFTER Installing them, I Blew-Out 2 Different sets of Head Gaskets..Believe it. At higher Revs, a Huge BANG and the Results, Water in the Oil and Oil in the Water, Boiling Over-Steam and Transport Home. The Gaskets Also Failed Between Two Adjacent Cylinders. The Cause...From at least 2 sources, I was advised to Torque the Heads to 90 Ft/Lbs (For a Fine-Thread Nut). Yes, In Levels and in Sequence. Before the Third set of Gaskets went in, I called and talked to a ARP Technician, asked Him for advise and received a Short and Simple answer, 1/2" Studs, IRON Block, 130 Ft/Lbs !! Engine has Run Strong ever since.

I Must Add, for those who will ask. YES! You CAN Pull the Heads Off-Over STUDS, While the Engine is STILL In the Pantera!!! There is Just Enough Room, You have to Remove the Obvious parts and the Pressure Tank. AND Be 6' 6" Tall so You can LEAN WAY In Over the Fender (NO Belt Buckles, Zippers or Gene Rivets Please) and with ALL Your Strength, lift and slide that 75 Pound Iron Head Up and Off. You Have Aluminum Heads!? Your Home Free! But It will Still Take all Your Might to Bring Those Fine Threaded Nuts Up To 130 Ft/Lbs!! Believe it or Don't!

Yes, I knew the 'Book' States the Torque to be 125 Ft/Lbs for the Boss 351, But That Setting is for Factory Course Thread BOLTS, and here we're talking Nuts with Fine Threads. Last, be very careful, 130 Pounds is right On the 'Edge' of Stripping the Threads Out of the Nut And The Block.

Apologies for Hi-Jacking the Thread.

Hi Guys

Would you believe the same thing has happened again this time on no 2 journal. Same tapping noise around 2000 rpm so engine pulled to take a look.

It was no3 journal that wiped out last time (see pics earlier in this thread) and the crank was welded and new rod purchased. The 3/7 journal is still OK but no 2 is completely wiped out. When the engine was at the machine shop last time all the rods were inspected for straightness and of course no 3 replaced. Crank was ground -10 and all new rod bearings fitted including new mains. Big ends checked for size.

How come this has happened again, any ideas, the engine has done less than 100 miles since the build.

New STD oil pump, lifter bores sleeved, oil restrictor kit fitted. Main bearings are all good so that tells me the oiling is OK so why would it wipe out one half of a rod journal and bearing yet the leave the other intact.

I am at a loss on this one and thinking I should replace with a new crank and rods. However that's easier said than done over here. Before I splash out the money could the same thing happen again, I need to identify whats causing this.

Not going back to the original machine shop, lost complete faith in them.

See pics below on No2 bearing with less than 100 miles. Rod journal exactly as the previous pictures, totally worn with about 40thou wiped off

Cheers
Horace

cap

i'm going with the same thing i said the 1st time, flipped / mixed / mis-aligned rod caps, unfortunately very hard to prove after it's taken apart unless the cap is clearly marked and found to be on the wrong rod