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I just recently rebuilt my engine by resleeveing my block, running a standard set of some TRW dish pistons (9 1/2 to 1), reworking the closed chamber heads, a Perfomer Intake, .56 lift (intake and exhaust) with 110 separation reground cam from Scnider here in San Diego and a Holley 750. I took it over to the Dyno to test before installation. After cam brake-in we did several pulls and the best it did was 350 HP @5200 RPM. Is this is good as it gets? Was I expecting to much?

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Also, Pantera exhaust can be pretty restrictive.  Not sure if you ran your stock (or stock-ish) headers/tailpipes.



My builder thought there would be ~50 more horsepower in my engine if I went to a less restrictive exhaust….  

I run Hall headers, modified collectors and enlarged pipes to the stock mufflers…

I didn’t want to shell out the $ and effort for a new “bundle of snakes” exhaust system…

Rocky

Last edited by rocky

...In My Opinion, You should have gone with the TRW Flat-Top Pistons. With a 10.5 CR*, proper carb and Manifold you'd be Pushing 'near' 450 HP, at the Flywheel. The Cam and Headers, look correct for it.

* a 10.5-10.6 Compression Ratio would depend on the Cyl. Head Chamber Volume...All other factors being the same. Replacing the Dished Pistons and keeping the CLOSED Chambers, Really Wakes these Engines Up. Just be sure to us the Highest Octane 'Pump' Fuel, you can find. Has Never been a Problem with my cleveland at 63cc Cambers, .588 lift cam (int and Ex) at a 292 Duration on both. Also, had the bowls Polished, Ports Untouched, Huge Valves. When I ran dual quads, the HP was at 520. Torque 490.

Now, I run a Dual Plane 'Air-Gap' with a Holley 750 Vac/Sec (for the Street), Data Input were at  the Minimalist Values, processed on a 'Desktop Dyno' Program. 480HP/450Torq. If I were 'Racing', I would go with a 'Double Pumper' Mech-Secs...Or FI.  All figures are + or - 5%. FWIW

MJ

Last edited by marlinjack

It is probably more accurate to ask Dan Jones that question but it may be him that came to the conclusion.

It's actually a driveline loss. Maybe it is less with CV joints?



If it were the percentage and that is around 15% an 800 hp Pantera wouldn't loose 120hp  and a 70hp engine wouldn't loose just 10.5 hp.



The number logically is a minimum + a percentage of something. Not necessarily a percentage of the hp.

More likely the engine torque.

He's probably the one to come up with the number?



The original design engineers who sketched out the general outline would know more precisely since they'd have to match the components. A 1.5 inline 4 cylinder would not have been a good match to the ZF. I've never seen the engineering numbers stated in those regards to the expected operating losses.



Ask Dan. Whatever he says. I haven't heard of him in years though since he had a running in with George over editing his posts?

I found his testing results interesting and informative. Did he ever finish the project? I miss him.

Last edited by panteradoug

384 CUI.

Here are the specs:

> Dan Jones might be willing to make some comments.
I'll do a full write up a little later this week when I can find the
time but some basics are:
A 4.04" bore Probe forged flat top pistons (1/16", 1/16" with 3mm oil
rings)
A 6.125" Scat forged connecting rods
A 3.75" stroke Scat forged crankshaft, internally balanced (Part
Number: 4-351C-3750-6125)
A 4.04" bore x 3.75" stroke = 384.6 cubic inches
A 11:1 compression
A Solid roller cam using Reed ULX lobes:
A 254/258 @ 0.050" (R290ULX/R292ULX), 0.692"/0.701 less lash (0.024"
and 0.026"), 110 LSA
A Competition Cams solid roller lifters
A PBM/Erson 3850 chrome silicon double valve springs with dampers
A Installed at 1.950", 223 lbs seat and 582 lbs open for the intake,
601 lbs for the exhaust
A Titanium retainers
A Rollmaster timing set that's made for the Cleveland block/SVO style
crank combination
A Oiling mods are bushed lifter bores on the right side only with an
0.040" restrictor in the back of the left side galley
A Stock volume and pressure Melling M84A oil pump, Melling oil pump
drive shaft and Aviad Pantera pan
A Clearances are .0025 mains .0022 rods using Federal Mogul mains and
Clevite rod bearings
A Main bearing size is 1/2 under and rods are -1 to get these
clearances with the Scat forged steel crank.
A Romac harmonic damper
A Ford Motorsport A3 high port aluminum Cleveland heads
A Ford Motorsport A331 (modified by Dave)
A 1.73:1 ratio Competition Cams "gold" aluminum roller rockers
A Jomar stud girdle
A Manley guide plates
A SI stainless valves (2.19" intake, 1.71" exhaust)
A Cooling system modifications
A 0.100" diameter block bypass passage plug, petcocks in the back of
the heads to let air out of the rear of the engine with a -4 AN line
from each head that tees together and runs to the suction side of the
water pump with a 0.060" restrictor so that the engine always pulls
coolant and any bubbles out of the back of the heads
A Cometic MLS head gaskets with Fel-Pro gaskets elsewhere
A MSD Pro Billet distributor with bronze gear
A Autolite 3923 spark plugs for street (moderate heat range), AR 3910
for race (about 2 heat ranges colder than the 3923s)
A 30 degrees total timing
A Precision Proformance high port Pantera headers
A 830 annular discharge Holley (from Mark's previous engine)
Mark runs his Pantera in open road races and rarely drives it on the
street.A His ZF has the original gearing so we wanted something that
would pull well from 3500 to 7000+ RPM.A I designed the cam to
maximize the power between 4000 and 7000 RPM, with a torque peak at
around 5000 RPM.A I designed several cams using the Reed ULX lobes and
the one chosen was the smallest (lowest overlap) and had the best power
below 6000 RPM, along with the flattest torque curve.A The Reed ULX
lobes are older designs that are relatively easy on the valve train so
work well in endurance racing and marine applications.A Dave spent
some time modifying the A331 intake.A A 1" thick open spacer was
milled to level the carb and welded to the intake.A On top of that,
several 1" spacers with an HVH 1 inch merge spacer working best.
Dynomation was predicting a little under 600 HP and usually
under-predicts the so I thought we'd hit 600 HP.A Final results were
623.1 HP at 6900 RPM and and 521.6 ft-lbs at 5100 RPM running through
the 4-into-1 Pantera headers with 2 1/2" pipes and mufflers.A The
torque curve is really flat in the operating RPM range.
More details to follow...
Dan Jones

I tested the engina out of the car. The dish pistons were the only standard bore I could find. I re-sleeved all 8 holes because I went through 2 other blocks that were standard bore that would not clean up and would have been to thin after boring. Unfortunately I have learned a few things about Cleveland engines the hard way. It more than likely has less than 9 and 1/2 to one compression so it will run good on this crappy California gas. The engina sounds cool, revs nice and looks fast (all show and no go). I wanted to use aluiminum heads with a matching intake and a differant rotating assembly, but almost everything is not avalible for the Cleveland. I'm going to build a Windsor like I should have in the first place, cheaper,lighter and parts are avalible.

“but almost everything is not avalible for the Cleveland.”

❓❓

unless you are looking for sodium filled exhaust valves, forged titanium crankshafts and triple 2 barrel carburetor intake manifolds, Cleveland parts are readily available if you shop in the right places.

I built a 404 Cleveland stroker recently and had no frustration in obtaining parts.

Larry

OK, the engine was not tested on a chassis dynometer. 350 flywheel HP  

(hopefully a more knowledgeable owner will chime in on resleeving of all eight cylinders, but for a standard production, cast iron block I have never heard of more than two or three cylinders being re-sleeved)  

with that established, I also would be a bit disappointed with just 350 HP. That isn’t a bad result, but for a fresh engine build it is far from what should be easily obtainable

For a rough comparison, I recently built a 9.2 compression 404 stroker Cleveland with no custom parts other than the bullet cam shaft and a Bob Oliver blueprinted Holley 670 Avenger, and pulled 454 flywheel HP at 5700rpm  

applying a ZF frictional loss of 20% from the 350, which is in line with what I’ve been hearing for the last 20 years, you will show only about 280 RWHP.

Larry

Last edited by lf-tp2511

Funny.

You’re probably not gonna get a lot of sympathy with this crowd about your decision to go to a Windsor.

Good luck with your engine build though.

Most people on here are probably pretty happy with their Clevelands, and are pretty big fans of them.  I am.

Hopefully once you get the engine in the car and driving around for a while you realize how much fun the cars are, even with stock horsepower levels.

Rocky

Last edited by rocky
@ehpantera posted:

384 CUI.

Here are the specs:

> Dan Jones might be willing to make some comments.
I'll do a full write up a little later this week when I can find the
time but some basics are:
A 4.04" bore Probe forged flat top pistons (1/16", 1/16" with 3mm oil
rings)
A 6.125" Scat forged connecting rods
A 3.75" stroke Scat forged crankshaft, internally balanced (Part
Number: 4-351C-3750-6125)
A 4.04" bore x 3.75" stroke = 384.6 cubic inches
A 11:1 compression
A Solid roller cam using Reed ULX lobes:
A 254/258 @ 0.050" (R290ULX/R292ULX), 0.692"/0.701 less lash (0.024"
and 0.026"), 110 LSA
A Competition Cams solid roller lifters
A PBM/Erson 3850 chrome silicon double valve springs with dampers
A Installed at 1.950", 223 lbs seat and 582 lbs open for the intake,
601 lbs for the exhaust
A Titanium retainers
A Rollmaster timing set that's made for the Cleveland block/SVO style
crank combination
A Oiling mods are bushed lifter bores on the right side only with an
0.040" restrictor in the back of the left side galley
A Stock volume and pressure Melling M84A oil pump, Melling oil pump
drive shaft and Aviad Pantera pan
A Clearances are .0025 mains .0022 rods using Federal Mogul mains and
Clevite rod bearings
A Main bearing size is 1/2 under and rods are -1 to get these
clearances with the Scat forged steel crank.
A Romac harmonic damper
A Ford Motorsport A3 high port aluminum Cleveland heads
A Ford Motorsport A331 (modified by Dave)
A 1.73:1 ratio Competition Cams "gold" aluminum roller rockers
A Jomar stud girdle
A Manley guide plates
A SI stainless valves (2.19" intake, 1.71" exhaust)
A Cooling system modifications
A 0.100" diameter block bypass passage plug, petcocks in the back of
the heads to let air out of the rear of the engine with a -4 AN line
from each head that tees together and runs to the suction side of the
water pump with a 0.060" restrictor so that the engine always pulls
coolant and any bubbles out of the back of the heads
A Cometic MLS head gaskets with Fel-Pro gaskets elsewhere
A MSD Pro Billet distributor with bronze gear
A Autolite 3923 spark plugs for street (moderate heat range), AR 3910
for race (about 2 heat ranges colder than the 3923s)
A 30 degrees total timing
A Precision Proformance high port Pantera headers
A 830 annular discharge Holley (from Mark's previous engine)
Mark runs his Pantera in open road races and rarely drives it on the
street.A His ZF has the original gearing so we wanted something that
would pull well from 3500 to 7000+ RPM.A I designed the cam to
maximize the power between 4000 and 7000 RPM, with a torque peak at
around 5000 RPM.A I designed several cams using the Reed ULX lobes and
the one chosen was the smallest (lowest overlap) and had the best power
below 6000 RPM, along with the flattest torque curve.A The Reed ULX
lobes are older designs that are relatively easy on the valve train so
work well in endurance racing and marine applications.A Dave spent
some time modifying the A331 intake.A A 1" thick open spacer was
milled to level the carb and welded to the intake.A On top of that,
several 1" spacers with an HVH 1 inch merge spacer working best.
Dynomation was predicting a little under 600 HP and usually
under-predicts the so I thought we'd hit 600 HP.A Final results were
623.1 HP at 6900 RPM and and 521.6 ft-lbs at 5100 RPM running through
the 4-into-1 Pantera headers with 2 1/2" pipes and mufflers.A The
torque curve is really flat in the operating RPM range.
More details to follow...
Dan Jones

Just off of the top of your head right?

I have the Torker manifold that has a 1" spacer welded on top. Also have changed to a billet 750CFM carb. from Competition Carburation per Dave McLain's recommendation.  I also using Pantera Parts Connection headers with a 3" collector and 3" straight thru exhaust pipes.

If you would like to read Dan Jones writeup regarding my engine click on the following link:  ***************************/viewtopic.php?f=4&t=577

Mark

I refuse to pay 3000.00 plus for s set of heads for a dumb 351 C. I should have built a Windsor but, I guess I'm as dumb as a Cleveland.

Those Cleveland heads are likely worth every penny! Why do you think builders purchase canted valve (Cleveland) heads and put them on a Windsor to make a 'Clevor'?

@ehpantera posted:

You get what you pay for.

A very interesting engine for sure.

I had read previously that the A331 Torker needed some work to even the flow. It had 4 good runners and 4 bad ones. I suspect that's what was done there?

That's a lot of cam for a street car. Kind of a "Pro-street" profile but I have no doubts it's very effective on a track.

I personally like the A3 heads even over the C302's. The C's that I have seen prepped wind up with ports very similar in volume to the A's.

They are borderline for my 357 but they absolutely will light up a 383.



My cam is a 244@ .050, .606 lift. and that's about as much as I'd go on the street. As a matter of fact I'm considering going down to the 236. You need at least around .588 actual to make these heads work. Under that and you are wasting them.

I'd suspect that the Holley probably has better numbers overall then my 48ida's do but I doubt that the Weber manifold is overdone or that it could be improved anywhere. The only thing that you could do with it is lengthen the runners. They are already at 51mm.

Maybe they could be reduced but I don't see where that helps anything?

It already has line of sight to the valves and the distance is thought to be optimum.



I'd want to dyno with the 180° headers. I'd like to see where they peak on the dyno. I already think that it's at 6,500 now but the dyno would be the safe way to test that.

The other thing would be to see if the engine benefits from 51mm throttles v. 48. I suspect that it does but don't know what that does for street drive ability. It could be a negative.



Thanks for posting your build sheet.

Last edited by panteradoug

Two thoughts for future builders: first, not many U.S-cast 351-C blocks will survive an 0.040" overbore. Back in the day, Ford recommended only 0.003" oversize and yes- that decimal is correct. A few that have tried big bores found the remaining cylinder walls were so thin, piston rings would not seat due to wall flexing, so such engines were forever oil burners. Thoroughly sonic-test any candidate blocks or use a siamese wall Aussie, racing or Tim Meyer's block! Note- not all  'Aussie' blocks are thick-wall, either. The ones that are, weigh about 50 lbs more (200+ lbs) than OEM.

Second- sleeving more than one (1.0) cylinder on each bank of OEM 351-C blocks can and has caused block cracking at the intersection of the lower end of the sleeves and the center main bearing supports, due to the amount of supporting cast iron that must be cut away. A multi-sleeve block may be OK for a while around town, but I would not go for high power with it! The only reason early drag racers got away with this is because they furnace-brazed big sleeves in place! And that forced remachining of every surface in the block including  head surfaces, cam & main bearings and lifter bores, due to heat distortion!

Yes Mr. Boss, after monkeying around with two other standard bore blocks and finding them not worth spit I decided to go back to my original block that was 40 over. I refuse to pay a gazillion dollars for a new block even if it was available. I'm not going to pound on this engine, I will just drive it to the swap meet and the store or just make a excuse to drive it. It will not be a rocket but will still be kinda cool to drive until somebody wants to buy it. I think keeping the original numbers engine is a good idea.  I really appreciate everyone's input and help on this car because there is a lot not so ordinary stuff that goes along with a Pantera. I will be installing the engina tomorrow. BTW I spent more money and time revamping the heating and A/C system than rebuilding the engine.  

The very first time I drove this thing it smoked like the devil, overheated and puked everywhere. The block was already .040 so I elected to re-sleeve all 8 holes to try to keep it running cooler with a standard bore. This is the first time I have done this because I always just would throw a block in the scrap bin. Viable Cleveland blocks have got hard to find and after market ones are moocho denaro. Standard pistons were hard to get as well I have found. If and when I build another SB ford it will be a Windsor, parts are somewhat cheep and widely available. Getting 600 HP can be got without hardly trying. A Hemi headed 429 would be bad ass, has anyone shoehorned one in one of these cars?

Some early 351-Windsor blocks turn out to have the same thin cylinder walls as was infamous for Clevelands, as the Ford Casting Plant #1 in Cleveland switched its casting technique to the new upside-down 'thin-wall' method. So using a W block is not an automatic free pass in overboring. I've also heard of wall problems with early 302 blocks, for the same reason.

On a pair of 0.030"-over blocks- one later blew during a SS race, and another that cracked after a backfire (cold engine) on the starting line, (coolant running out the right tailpipe), I found pieces of off-center cylinder wall only 0.070" thick. Chevy guys get nervous if their cylinder walls drop below 0.200"- which NO factory Cleveland ever had. I suggest sonic testing ANY '70-74 V-8 Ford blocks for wall thickness checks, if you intend to bore oversize. YMMV....

@bosswrench posted:

Some early 351-Windsor blocks turn out to have the same thin cylinder walls as was infamous for Clevelands, as the Ford Casting Plant #1 in Cleveland switched its casting technique to the new upside-down 'thin-wall' method. So using a W block is not an automatic free pass in overboring. I've also heard of wall problems with early 302 blocks, for the same reason.

On a pair of 0.030"-over blocks- one later blew during a SS race, and another that cracked after a backfire (cold engine) on the starting line, (coolant running out the right tailpipe), I found pieces of off-center cylinder wall only 0.070" thick. Chevy guys get nervous if their cylinder walls drop below 0.200"- which NO factory Cleveland ever had. I suggest sonic testing ANY '70-74 V-8 Ford blocks for wall thickness checks, if you intend to bore oversize. YMMV....

Just two weeks ago I saw a NEW NASCAR XE block. It was brand new, in a Ford box with the original Ford Service Parts order label on it, from the ordering dealer.  It had the Gelong icon and was still in the cosmolene.

It was standard bore and came with a sonic testing chart. There were no cylinders less then .280" thick.

It was the first one I saw close up and I think it was closer to 100 pounds heavier then my D2 4 bolt block. What a chunk of iron...and yes it APPEARED to be legit!

I didn't buy it because the price was $3500 FIRM. Of course if I had the money I'd probably be staring at it right now.



That B9 might be the one that they ran at Bonneville. Mike Cook may have something to do with that as well, if you can find him.



You are no better off on a production Windsor. They are thin wall casting like all Ford PRODUCTION blocks are.

I think the latest "Ford Racing" aftermarket "Boss 302" block (a 351W) WAS the most reasonable at something like $2,200 from Summit?

As stated previously, the Windsor block in a Pantera chassis is going to take "just a little bit" of modification and if you aren't using Cleveland heads, you were missing the point entirely. Using Windsor heads isn't really where you want to go.

You should have by now (50 years later) seen the data I would think?

Last edited by panteradoug

Can't help putting my engineer hat on sometimes.  I have been skeptical of the drivetrain power loss figures -- 50 to 75 hp, 20%, or whatever is often times claimed.  Say you have a 350 hp engine and lose 20% for 280 rwhp.  That is 70 hp loss.  Each hp is approximately 750 watts.  That is 52.5 kilowatts of power loss.  Maybe the short duration of a dyno pull is the saving grace here.

Donnie, lets put this in perspective.  You want an 800 hp engine and a trans to match.  The old adage applies here.  How fast to you want to go and how much money do you have?  The two go hand in hand.  The pantera is an appreciating classic with some pretty strong values for some of the more tastefully restored cars.  Spending $4,000 on a aftermarket engine block to me is a sound investment in the long term longevity of your car.  800 hp naturally aspirated is probably a car that I don't want to drive on the street very often.  The pantera begs for a high horsepower endurance engine.  George has a formula for a 500 hp or more engine using a stock cleveland block.  I used this for the basis of my build and I couldn't be happier.  As I understand it anything over 600 hp is the limit of the ZF.  Once again:  How fast do you want to go?  How much money do you have?

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