Build Your Own 91 octane, 500 HP, 377CID CLEVELAND?

Mark,

Sounds like you have the makings of a great engine there. I have been doing a lot of reading on this and I'm at about the same point in collecting parts for a rebuild on my '74 engine.

I have a 2 Bolt block bored +0.030", KB flat top pistons (10.5:1 CR), total seal rings, aftermarket 5.78" (Stock length) I-beam rods. The stock crank is in for a regrind and I'll drop the rest of the reciprocating asemmbly to the shop next week for balancing.

I was in the process of specing a solid roller cam, when last week it all got thrown to the wind as I picked up a great deal on a dyno time only 600HP, 393C stroker. So now the rebuild will go at a slower pace and be more geared towards a replacement engine for the GT5.

Good luck,

...Yes!! You are on the Right Track! This is My Opinion and My Opinion ONLY! I also went with the 70-71 Heads. 63.0 CC Chambers. Stay with the Iron Heads! Sure they weigh 'Tons' More, and They Make Tons More HorsePower and Torque. Canted, Huge Valves 2.190, 1.715 Valve size is the Single Most Significant Factor Effecting HP and TorK!! Compression Ratio coming in a Close Second! Don't get talked into Those aftermarket 'Aluminum' Heads! The Valves and Ports are 'Tiny Weenie' by Comparison. What for? 'Low RPM Velocity'!? Do You Plan to 'Race' at 'Low RPM'?? Hell NO!! Your going to be Into the Higher REVS in About 'Two Tenths of a NANOsecond'! It's all About 'Cylinder Filling' or, we call it 'Volumetric Efficientcy', and The Large Valves and Ports Deliver!, When and Where YOU Need It! Have the Heads 'Pocket Polished', Do NOT Polish the Ports as You need them left 'Rough' to Maintain 'Fuel Suspension' and Aid in 'Fuel Atomization'. Have Hardened Valve Seats installed, Only Needed on the Exhausts. Before this was done My Exhaust Seats started to Receed into the Stock, Softer, Seats. You can build over 700 HP with the Iron Heads! It's been done before and there are articles on the subject in the archives. With Your Solid Roller Cam, and Your selected Lift/Dur., You will be at 620 HP and Higher. I went with a More 'Streetable' 560 Lift, 292 Duration, Yes! A 'Flat Tappet' Camshaft, Putting Out 525 HP and 450 lb/ft of Torque! I am Running Dual 450 Holleys on a HIGHLY Modified Weiand Manifold. Engine UNstroked. You gotta hear this thing idle! Just Sweet and Perfect at 900-1000 RPM. Jump on it at 'Cruise' and it's a 'Sledge Hammer to The Backside'!! No Brag, Just Facts! Good-Luck with Your Build! It Sounds Wicked! On More thing!!! For those persons having trouble locating the Correct 351 Cleveland Thermostat! I just installed the Milodon Hi-Flow '180' Degree Part #16401. A few are Now being sold on Ebay. I tested one, in heated water, with a Thermometer, and precisely took measurements; When Open it does it's job of lowering and Blocking off the 'Brass By-Pass Restrictor Plate' to Ensure that Near 100% of the Coolant is pumped to the Radiator! I Took the Cat out Yesterday, I Have a Digital Temp Gauge that read between 177-181 Degrees, Cruising 90-100 MPH on the Freeway. Coming off the Interstate onto local roads it hit a High of 188 Degrees! Yes, Both Fans Running. Be sure and select the 180 Thermostat! 160 is too Cold!!! You will run into problems of fuel not atomizing properly, increased cylinder wall wear, and 'HEAT' IS ENERGY, HORSEPOWER!! The Hotter Engine Makes More HorsePower! It's a simple Fact of Pysics! 'Believe It, Or Don't'!! Anyway, Something to think about, if You Care to 'Listen'. Took Me 40 Years to Learn Most of This...

MARLIN JACK,
Thanks for the backup, I knew that these heads were the way to go! I had hard seats installed with the rebuild on the heads.
I have a Holley Spread Bore 750cfm #6210-3 model 4165 mechanical secondary double pumper or whats on the Pantera now which is a Demon 750.
I will be milling the Holley Strip Dominator flat and Down when I get all my measurements right & triple checked before I setup and fire up the Mill! Like to have it all fit under the stock engine screen.

I'm amazed at what the heads flow,

"pulled off another post"
351C-4V
lift int exh int int
#1 #1 #2 #3
.050 33.6 27.1 32.7 31.1
.100 64.7 55.9 64.6 64.1
.200 123.0 100.1 129.8 134.5
.300 188.5 138.9 195.1 200.2
.400 246.4 166.4 251.7 253.3
.500 294.5 182.7 296.5 294.6
.600 322.1 186.5 322.5 322.0
.700 333.3 185.2 338.9 330.2

Looks like Rpm's & lift is what the doctor ordered.

Thanks again,
Mark

...Wait!!!!! Don't Mill the 'Strip Dominator' unless you Know that this will Ruin It's Value of ever being resold to someone who may want to use it on a say; a Mustang!!! The way to do it is to Get a One inch thick Aluminum spacer and mill THAT at an angle!! This angle will be achieved when the Thickness of the 1.0 inch plate is Milled down to a thickness of: .940" in the Front and .600" in The Rear or a Difference .340" Between the front and rear! I Know because I have done it. I would sell You the spacer, But I may need it in the future. Do This Milling Operation on a Spacer, it will be less expensive for You in the Long Run...

Mark,

I don't think you are going to see those sort of quoted flow numbers from stock 4V heads. Here's a nice website where flow numbers are compared for various Cleveland heads;

Cleveland Head Data

Gents,
I obtained or copied these head flow numbers off this site at; http://pantera.infopop.cc/eve/forums/a/tpc/f/5650045562...690015564#5690015564
Anyway's I feel these are reasonable #'s,from a reliable source.
As for the intake I will cut it, if it will work. It isn't like I'm irreversibly hacking on a Pantera body part.
Just received my correct roller rockers, had gotten incorrect sized holes 5/16" instead of the correct 7/16" on the rocker pedistals, these were COMP Cam's 1.7 pro magnum roller rockers #1330-16 to fit ARP 7/16" rocker studs #100-7101.

Mark

Hi all,
We are back on line for the build! My Crank grinder had some serios health issue's in there family so we had to wait, the crank is complete and has measured out at 3.700", was heat treated, hardened and ground, these guy's do excellent work.
I had to decide on rods today, Chevy titanium or Callies H beam, I decided on the Callies @ 6.125".
We also picked the Forged pistons today as Probe #14617, .020" over standard,
We cc'd the 1970 4V heads DOAE-N @ 61.5cc to 62cc's, this will yield approx 10.6:1 compression ratio,

If you need some advice my engine guy is; Keith at Rancho Performance Machine, 28073 Diaz Rd, suite I, Temecula Ca 92590, 951-676-9292.

Mark

quote:

I'm amazed at what the heads flow,

"pulled off another post"
351C-4V
lift int exh int int
#1 #1 #2 #3
.050 33.6 27.1 32.7 31.1
.100 64.7 55.9 64.6 64.1
.200 123.0 100.1 129.8 134.5
.300 188.5 138.9 195.1 200.2
.400 246.4 166.4 251.7 253.3
.500 294.5 182.7 296.5 294.6
.600 322.1 186.5 322.5 322.0
.700 333.3 185.2 338.9 330.2

Those heads received some work to them. Cleveland heads are known for poor exhaust numbers. It doesn't matter if you have good intake numbers, if the exhaust is going to hold it back. They are a good head for high rpm numbers. If you're going to spend money on port work ($60-$80/hr), then you're better off to go with an alloy head.
Will

Those flow numbers are ones that I posted. I supplied the heads for Glen Hartog's 408C. The heads received a 3 angle valve job and short side radius work only. It was best bang for the buck type job. Cost for the labor was $150 for the short side work and $150 for the valve job. We weren't able to equal that on a second set of heads because they were not in as good of shape (had several previous valve jobs).

Dan Jones

Hi Dan,
I read that post along while back and it was what set me on the coarse I am on. Thanks!
I wanted to keep my Pantara with a stock theme yet squeeze all the availble power from the package.
Also I know the easy way may have been to go the route of the Windsor/Aluminum Head that alot are doing, but I felt it would be taking away from the total appeal of the Pantera, After all there are other combo's like Hemi's, Chevy's, Big blocks that would be less expensive with Huge HP results.
Anyway's thanks again for helping with Cleveland Engine's.
Did you see the Head that I posted on the other thread? Check it out, It's been used in different application's with great results!
http://www.ultrapromachining.net/index2.html

Mark

Is that the FRPP D3 head? If so, Vizard has tested it and it's the top of the heap. Relatively small, very active ports, that flow over 400 CFM.

Dan Jones

Those may be there Drag Race version, The ones I saw were there street version with water jackets.
D3 refer's to the angle of the valve seat but I could not connect up the FRPP.
This is something they offered:
http://www.gofastnews.com/board/technical-articles/47-b...nder-head-power.html

Mark

I agree with what you guys are saying about the close chamber stock iron heads. The Boss heads I ran were amonst the best I ever ran.
I tend to disagree a little with the aluminum head comment. I was fortunate enough to get a pair of the "old" (1982) Ford Motorsport A3 headss for my engine.
They are a good compromise between decent low end torque and out and out Bonzi flat out power.

My suggestion is that don't pass up a pair that is available. The highport exhausts tend to work pretty well in a Pantera with 180 degree headers. Buy them if you can especially if you can get a matching intake with them. You won't be disappointed in them.

If you want to build an 8,500rpm street/track Pantera they are the way to go in my opinion. Don't even look for the C302 heads.

Had a chance on christmas eve to machine the manifold the way I wanted,
Cut the angle off the carb mount and redrilled the holes straight and threaded for a plug with the right size 5/16" thread, removed the regular linkage attachment pads and need to sand and blend the rest before polishing. Height off block from the edelbrock performer is another 1/2" high, I can still keep the factory engine screen by going to a thinner air cleaner.

Mark

*

#

This is the end you will be looking at when it is all polished and in the car

Nice. I like the thinking. I think Iron heads always worked if you know what to do with them. An hydraulic cj cam isn't going to cut it for sure.
Marlin is right too. You need to turn rpm's to make hp. The only thing about the C is the power is peaky. At first there is nothing there and then the thing just seems to explode.
It makes a hell of a sound doing it to, one heck of a womp.

The key in the Pantera ultimately may be how unrestrictive you can make the exhaust system. A 180 system is one way out.

Keep us posted on your saga. Thanks for posting.

I think Mark is on his way towards building a nice motor. I love the Strip Dommy intake for the way it takes maximum advantage of the 4V cylinder head's high rpm capabilities. The lower rpm performance of the manifold is not the best, but it seems to do alright in the Pantera.

The 351 Cleveland can make 500 bhp with a cam having lobe lift in the 0.600" range, at 6500 to 7000 rpm. Mark's 377 stroker should be able to hit 500 bhp at a bit lower rpm, perhaps as low as 6200 rpm.

Head work needed on the intake side is minimal: Bowl clean-up and a multi-angle valve job. The exhaust needs more work, in the port roof, the short side radius, and some unshrouding in the combustion chamber; but nothing too radical to achieve a goal of 500 bhp.

Recessed valves are a killer on any motor, if the heads have any valves that are sunk into the seats (recessed) you want to repair them. Install seats or grind the chambers and get all the valves sitting on top of the seats, not sunken into them.

Finally there's the exhaust system as Doug so rightly mentions, you want the back pressure low enough to achieve your goal of 500 bhp, and to allow the engine to rev as high as you expect. But it also has to meet your noise expectations. High output verses moderate exhaust volume is definitely a juggling act with the Pantera.

I was running a Torker and a 750dp Holley with Boss heads and valve train. I would say the thing was pretty ho-hum flat till around 36 then it would crispen up and start to growl and would explode at about 4200 to the point of being unsteerable. It was a very peaky combination. With the dyno testing done since then showing that perhaps the issue was in the intake manifold then the Dominator should have been what to go with. Who knew then? Not everyone had a dyno in the basement like now.

I never had the pleasure to try the Dominator. It could be the key to the big 4v iron heads.

Keep me posted. I need to know this stuff so I can sleep at night.

I'm thinking about building a simple engine rack to run the engine in on, I want to strip the rocker's off the Heads and retorque the head bolts and reset the clearances out side the Pantera before installation, this can also be used to store the old original block on afterwards. ????????? I got to find my welder, it's buried in the garage somewhere, and my weldhood, damned I need more room man.
All the toys are taking all the room, geeze where does it end???????? (':')

I'm here to help. You can store the Pantera or the Vette in my garage. Must leave key just in case the house goes up in flames.

I don't see much more room in that garage but a test stand for me has been invaluable. Everything from running down leaks to basic set up. It is also a breath of fresh air to hear the engine run when the car is in a 1000 pieces; real motivator; although it would help to make sure your rpm gauge is working. After I got my rpm gauge hooked up I realized I was reving mine well above 5500rpm!

One pointer.......Get Very Good casters; better then you think you need. They are rated by weight but go at least an extra 50%. I had a doleys with casters which were just rated for the weight and it rolled the wheels off.

A good point made on the casters.
I used 6 inch when I built mine.
My shop floor is pretty bumpy and uneven at the seams.
With the 6 inch casters it rolls very easy over the problem areas. At that size I will not ever worry about over stressing them.
Actually it rolls too easy and I had to make some simple wheel locks to keep it from rolling away!

Hey Mark,
I'll keep it in mind, if you look above the Pantera there is a 63 chevy II hard top, LT1 350 450HP/ Turbo 400/ narrowed 12". Itching to get after that after the Pantera, I'm going towards a streetable bracket car.

Brooke & Comp2, Thanks for sharing your idea's & Pic's, I'm going out & starting the process to build a stand today.

Mark

Found my welder, cut, aligned, and welded pushrod guides

a

b

c

Will finish final adjustment & torque with locktight, this has been a back and forth effort and I want to get past this, A person should not weld on the engine as the weld splatter would surely damage the springs.

Also finished part of the engine run stand.

re: welding split valve guide plates- besides spattering little steel dingleberries everywhere, if you do this on the engine using an electric welder and have an upgraded ignition, you can kiss your MSD or other spark-box goodbye, too....

quote:

Ok so here's a great build...483 hp...351c, ... It's not my motor, but I was talking back and forth about my engine build and before you know it I had all the specs.

So who's engine is it? Thanks for sharing!

Charles Engles

quote:

Ok so here's a great build...483 hp...351c

No sir, not me. That is too much horsepower for an old car and an old driver like me. That would make me have to upgrade brakes, suspension and all sorts of stuff and I am already broke the way it is. Not to mention having to change underwear and pants and using upolstery cleaner. No way, 400 horsepower is more than enough for an old fart like me, thank you very much. I am sticking with the George Pence build he suggested for me. You can just go take your 500 horsepower and play somewhere else. Thank you.

quote:

351 Cleveland Build….483 hp @ 6200 rpm & 436 ft lbs of torque at 5800 rpm

WOW
Jeff

Why is everyone surprised? Haven't you been paying attention?

Put on a good set of modern heads on this engine and it is easy 500hp.

I tell everyone mine is 563/450 torque on the dyno and no one believes me.

The crank is described as "ten under". What does this mean?

The peak horsepower is reached pretty high on the RPM scale. Is that a characteristic of the Holley Strip Dominator? Would a Street Dominator reach it's peak HP earlier? About how much HP would you lose with the Street Dominator?

This looks like a great engine to copy!

Thanks, Mooso

Mooso, "ten under" means the crank was reground to ten thousandths of an inch under it's original diameter. This is pretty common when rebuilding the bottom end with new bearings. It just cleans up the surfaces to a like new bearing surface. I don't believe there is any performance gain(others may know better).