quote:
Originally posted by Carlo:
... I am looking for power in the 2000-5200 rpm. range and never spin the engine above 5500 rpm ...
Greetings from Bavaria
Carlo
Based upon your modest goals, the second engine with the Venolia pistons and 650 Holley seems to be close to what I would recommend. You can hopefully re-use the Venolia pistons if the dome volume is correct, this must be investigated.
I don't recommend re-using the Holley double pumper carburetor but you can re-use the Edelbrock intake manifold.
The Sealed Power (?) #CS-1021R camshaft can be employed, it requires valve springs with more lift capacity than the OEM valve springs. You should install brand new tappets, and since that camshaft is normally indexed "straight-up" it should be installed 3° advanced (ICL = 109°).
To get started we need to know the casting code of the heads, it shall be either D1ZE or D3ZE, you'll find it on the bottom of one of the intake port runners. Does the Venolia piston have any numbers on it?
The specs for the 1021R camshaft as you requested:
280°/290° duration @ 0.006"
214°/224° duration @ 0.050”
61° overlap
0.295"/0.310" lobe lift
112° lobe centerline displacement angle (LSA)
I have copied and pasted what I consider to be a baseline rebuild below. I am posting this "list" simply to give you ideas and kindle thought, perhaps it will help you to avoid overlooking certain details. Best wishes for success:
Overview of a Baseline 351 Cleveland Rebuild (365 BHP):1. The
MAXIMUM ENGINE SPEED of a “baseline engine” should be limited to 6200 RPM due to the dynamic limitations of certain parts it is equipped with. However an engine equipped with 4V cylinder heads will tend to make peak horsepower at 6400 rpm to 6500 rpm as its induction and exhaust systems are opened-up. Therefore if an engine equipped with 4V cylinder heads is to be rev-limited to 6200 rpm it only makes sense to limit the rpm at which peak horsepower occurs in order to prevent it from occurring above the rev-limit. Limiting the rpm at which peak horsepower occurs is accomplished via a small carburetor (600 cfm to 650 cfm) and a camshaft providing moderate valve lift. This is not a consideration for engines equipped with 2V cylinder heads, so long as the intake duration of the camshaft does not exceed 230° @ 0.050 inch tappet lift.
2. Prevention of known
RECURRENT FAILURE MODES; this includes:
___A. Replacement of the OEM valves with quality aftermarket valves. 2V valves are available via Sealed Power, p.n. V-2075 (intake valves) and p.n. V-2030 (exhaust valves); or via Melling, p.n. V1270 (intake valves) and p.n. V1269 (exhaust valves). 4V valves are available via Melling, p.n. 451134 (intake valves) and p.n. 451144 (exhaust valves). Sealed Power has a listing for the 4V exhaust valve (V-1879) but not the 4V intake valve. These valves should all have 4 groove valve stems designed for the OEM valve locks. Hardened steel versions of the 4 groove valve locks are available from Sealed Power, p.n. VK-205R.
___B. Replacement of the OEM connecting rod nuts with ARP connecting rod nuts p.n. 300-8371.
___C. Installation of tappet bore bushings (a do it yourself kit is available from Wydendorf Machine).
___D. Installation of the correct thermostat (Robertshaw p.n. 333; 180°F or 192°F).
3. Restoration of the
PERFORMANCE ROBBED FROM THE ENGINE by the reduction of the engines originally intended compression ratio (10.0:1) and by the Autolite/Motorcraft 4300 series carburetors which were calibrated for low-emissions.
___A. Setting the static C.R. at approximately 10.2:1 to achieve 7.8:1 dynamic C.R. (compatible with pump gasoline rated 91 octane in the US and Canada, or rated 95 octane internationally). This may be accomplished via off-the-shelf pistons in some applications, but custom pistons should more than likely be required for most applications.
Note: Ross Racing Pistons’ round skirt forged pistons are a bit of overkill for an engine limited to 6200 rpm, but Ross specializes in custom pistons, and their round skirt pistons are beneficial for the thin cylinder walls of the production Cleveland block. Ross pistons utilize modern thin piston rings and are drilled for wrist pin oiling out-of-the-box. Ross pistons are available via Summit Racing at a fair price, including special orders. Ross therefore is the piston manufacturer I recommend when custom pistons are required. The basis for your order shall be their +3cc flat top piston (Ross p.n. 80556) for quench chamber heads or their -14cc domed top piston (Ross p.n. 80552) for open chamber heads. The piston's diameter, compression height, and dome volume (if applicable) must be tailored for each application. I also recommend adding their optional anti-friction skirt coating called “skirt lube” (p.n. PC107B) while custom ordering the pistons.
___B. Improvement of the carburetion with either a Summit Racing p.n. M08600VS 600 cfm vacuum secondary carburetor or a Demon p.n. 1282020VE 650 cfm vacuum secondary carburetor.
___C. Replacement of a 2 bbl intake manifold or a “spread bore” 4 bbl intake manifold with a “square bore” 4 bbl intake manifold if needed. Manifolds for 4V heads include the 1970/1971 US Ford iron 4V manifold (casting no. D0AE-9425-L), the US Ford aluminum 4V manifold (casting no. D1ZX-9425-DA), and the Edelbrock Performer 351-4V p.n. 2665. Manifolds for 2V heads include the Edelbrock Performer 351-2V p.n. 2750 and Australians have the option of hunting down one of the iron manifolds that Ford of Australia installed in the early Falcon GTs.
___D. The carburetor mounting flanges of the US Ford and Australian Ford cast iron intake manifolds are of the 4-hole variety, the holes being sized for Autolite/Motorcraft 4300A carburetors. The holes will need to be opened-up to 1.7 inches diameter to accommodate the 1-11/16 inch butterflies of the aftermarket carburetors. The exhaust heat supplying the channel running in front of the primary holes should be blocked; the channel itself may need to be brazed-in if the iron ridge between the “primary holes” and the channel becomes too thin after the “primary holes” are enlarged.
4. Replacement of the mechanical fuel pump if it is more than two decades old. All rubber parts in the fuel system (i.e. hoses) and all filters should also be replaced.
5. Replacement of an OEM breaker point ignition with a Ford Duraspark II breakerless ignition.
___A. A Ford breakerless distributor which is compatible with a 351C can be sourced from any 1975 through 1982 351M, 400, or 460 cubic inch Ford V8. There are also businesses specializing in rebuilding and recurving distributors such as Ignition Engineering of Anaheim California (telephone 714-334-9143).
___B. The ignition calibration should be 20° centrifugal advance all in by 2800 rpm plus 18° initial advance for 38° total advance. Engines equipped with pop-up dome pistons may require more than 38° total advance, in those instances the ignition should be calibrated for 26° centrifugal advance all in by 3300 rpm plus 14° to 18° initial advance for 40° to 44° total advance. The vacuum advance should be connected to the carburetor’s “ported” vacuum connection; a vacuum retard connection (if provided) should remain opened to atmosphere.
___C. The Duraspark II ignition module (with a blue wiring grommet) is manufactured by SMP, p.n. LX203. The coil is available as SMP p.n. FD476. The wiring harness is available from Painless Wiring, p.n. 30812. A good ignition wire set is also available from SMP p.n. 69404 (Pantera owners will appreciate the fact that this wiring set has coil wires in 3 different lengths).
___D. If the engine’s dynamic compression ratio is in the range of 7.6:1 or higher, then the first set of spark plugs should be Autolite p.n. 24, Motorcraft p.n. ARF32, or Motorcraft stock no. 15. If the electrode insulators are too dark after the engine has been operated then a swap to the next size hotter spark plugs may be in order, i.e. Autolite p.n. 25, Motorcraft p.n. ARF42, Motorcraft stock no. 50. Spark plugs should be gapped at 0.050 inch for a Duraspark II ignition.
6. Replacement of all seals, bearings, piston rings, and gaskets.
___A. Seals include the crankshaft end seals and the valve stem seals.
___B. Bearings include the camshaft bearings, the crankshaft main journal bearings, the connecting rod bearings, the pilot bearing (manual transmission), and the throw-out bearing (manual transmission).
___C. Piston rings: Ross pistons are designed for a modern thin (1/16 – 1/16 – 3/16) piston ring set. Piston rings are not included with Ross pistons however, they are sold separately. I have no firm recommendation at this time; the rings should be purchased from Ross or elsewhere. They should be compatible with the motor oil you plan to use (10W30?) and your longevity goal for the engine (100,000 miles?). The cylinders walls will need to be honed to the finish specified by the piston ring manufacturer.
___D. Gaskets include the oil pan gaskets, the timing cover gasket, the coolant pump gasket, the fuel pump gasket, the oil pump gasket, the valve cover gaskets, intake manifold gaskets, the carburetor gasket, and the head gaskets (Fel Pro p.n. 8347, 0.048 inch compressed thickness).
7. Refurbishment of the cylinder heads:
___A. Hot tank the heads and have them checked for leaks.
___B. Check the valve guide to valve stem clearance with the replacement valves. Service the valve guides as needed. Sealed Power (Speed Pro) p.n. VG-7501R bronze valve guide inserts are recommended, shortened to 1.625 inch below the flange.
___C. Replacement of the valve stem seals with spring loaded viton valve stem seals, Manley p.n. 24045-8 or Ford Racing p.n. M-6571-A50. The upper ends of the Speed Pro bronze guides are designed for these seals.
___D. Enlargement of 2V valve pocket throat diameters (2V Cylinder Head Applications): The throat diameter of 2V cylinder head intake valve pockets can be opened-up to 1.74 inch diameter (same diameter as the 4V cylinder heads).
___E. Replacement of 2.04 inch intake valves: Heads equipped with 2.04 inch intake valves can be upgraded with 2.125 inch intake valves. Non-standard sized 2.125 inch intake valves shall require high end stainless steel replacement valves with single groove keepers. One possible valve selection includes Manley 2.125 inch “Race Master” intake valves p.n. 11344-8; complemented by Manley 1.655 inch “Severe Duty” exhaust valves p.n. 11807-8; and Manley p.n. 13083-16 heat treated machined steel 7° valve locks to mate with the OEM spring retainers.
___F. Check the condition of the valve seats, any badly worn or damaged valve seats should be replaced with iron valve seats. The cylinder head casting is thin in the area of the valve seats, replacement seats must be sized with this taken into consideration.
___G. If the valve seats are to be serviced their width, diameter, and angle should be sized and “profiled” with progressive cut multi-angle valve seat cutting. The first cut should be 70°, the valve seat angle should be cut at 45°, and the undercut should be 30°. The seat width of the intake valves shall be no less than 0.060 inch, and the seat width of the exhaust valves shall be no less than 0.080 inch.
___H. 4V valve springs are adequate for the Cobra Jet camshaft and a 6200 rpm rev-limit. Both the M-code and Q-code engines were equipped with the same valve spring, which is identified by 2 light green stripes and 1 white stripe. The nominal specifications for this 1.5 inch diameter spring are 90 pounds on the seat at 1.82 inch installed height, 390 pounds per inch spring rate, 0.505 inch maximum lift, and it coil binds at 1.215 inch.
___I. 4V rocker arm fulcrums are made of steel whereas the 2V fulcrums are made of aluminum, 2V cylinder heads should be upgraded with 4V rocker arm fulcrums. The fulcrums are available from Melling (p.n. MRM-1776) or Sealed Power (p.n. MR-1811).
8. The valve train for this “baseline engine” should include a Cobra Jet (engine code Q) hydraulic flat tappet camshaft. Aftermarket versions of the camshaft are available from Melling (p.n. SYB-29), and Sealed Power (p.n. CS-650).
The specification of the Cobra Jet cams:
• 270°/290° duration at 0.006
• 205°/220° duration at 0.050
• 0.481/0.490 gross valve lift
• 46° overlap (OEM) 50° overlap (aftermarket)
• 117° LSA (OEM) 115° LSA (aftermarket)
The Cobra Jet cams are indexed 4° retarded; they should be installed “straight-up”, i.e. advanced 4° beyond their indexing. The OEM cam should be installed with a 117° ICL, the aftermarket versions should be installed with a 115° ICL. Advancing the cam opens the exhaust valve earlier (80° BBDC) for improved high rpm performance and fewer pumping losses, it opens the intake valve earlier (20° BTDC) for increased horsepower (20° BTDC is not early enough to impact the engine’s drivability or vacuum however), and it closes the intake valve earlier (70° ABDC) for improved dynamic compression.
___A. The HT900 hydraulic flat tappets originally manufactured in the US by Johnson Lifters were once the best quality tappets you could buy. Tappets manufactured by Johnson were identifiable by the "smooth waist" (no ridges or raised bands within the waist) and the single thin groove machined above the waist. Each tappet manufacturer had their own unique combination of grooves and ridges. The HT900 tappet is still available; it is sold by Sealed Power (p.n. HT-900) and Melling (p.n. JB-900) among others. It is the recommended tappet to complement the Cobra Jet camshaft and a rev-limit of 6200 rpm.
The best quality tappets you can buy today are still manufactured by Johnson Lifters! The company manufactures low volume specialty tappets now. Their current Ford tappet is p.n. 4214R, it lists for $400 USD per set of 16, and it has a reputation for the best bleed-down performance in the industry. According to Johnson Lifters their tappets are available via Isky Cams and Crower Cams although I could not find the hydraulic flat tappets in the catalog of either company. A phone call to Johnson may be necessary to locate a retail outlet stocking their flat tappets. This tappet is recommended for high lift aftermarket cams and 7200 rpm rev-limit applications.
___B. One rule of thumb for adjusting hydraulic tappets is to never compress the plunger more than 1/2 of the plunger’s available travel; however it is important to actually measure the travel of the plunger to verify what it is. The plungers of modern hydraulic tappets do not compress as much as the plungers did decades ago. The plunger travel of modern hydraulic tappets is in the range of 0.060 inch to 0.080 inch. This means hydraulic tappet pre-load should be limited to 0.030 inch to 0.040 inch, and sometimes 0.040 inch will be too much.
There are two ramifications to this reduction in plunger travel:
• Even though your engine may be equipped with 100% factory valve train, if it’s using new tappets then OEM length push rods (8.41 inch length) are probably a bit too long.
• If your engine has adjustable rocker arms, you need to measure the tappet’s plunger travel and the thread pitch of the rocker arm adjuster, and compute how far to limit turning the adjuster to avoid compressing the plunger more than half of its travel. For example, the push rod cup adjuster of a T&D rocker arm has 20 threads per inch pitch, which means each complete turn of the adjuster pre-loads a tappet by 0.050 inch. To pre-load a tappet 0.030 inch would require only 3/5 of a turn with a T&D rocker arm.
___C. The OEM push rods are adequate for the Cobra Jet camshaft, 4V valve springs (278/281 pounds over the nose), and a 6200 rpm rev-limit … and nothing more.
___D. Shim kits are available for “slotted-pedestal” mounted rocker arms to reduce the amount of hydraulic tappet pre-load (plunger compression). The shims can also be used to fine-tune the rocker arm geometry (in which case push rod length would be altered to adjust hydraulic tappet pre-load). The shim kits are available in two varieties; both are available from Ford Racing. The first kit, Ford Racing p.n. M-6529-A302, is a set of 32 shims consisting of 16 shims 0.030 inch thick and 16 shims 0.060 inch thick. The second kit, Ford Racing p.n. M-6529-B302, is a set of 64 shims consisting of 16 shims 0.010 inch thick, 16 shims 0.020 inch thick, 16 shims 0.030 inch thick, and 16 shims 0.040 inch thick.
___E. Replacement of a high mileage camshaft timing set with a new timing set with steel sprockets, including a 9 keyway crank sprocket; Rollmaster p.n. CS3091, Ford Racing p.n. M-6268-A351, or Cloyes p.n. 9-3621X9. The multi-keyway crank sprocket facilitates accurately timing the camshaft (preferred sets use chains manufactured by Renolds or JwIS, avoid timing sets using Rolon chain). The premium Rollmaster sets were formerly called the red series, they are now known as the gold series.
9. Refurbishment of the engine block:
___A. Hot tank the block.
___B. Hone the cylinders in 0.005 inch or 0.010 inch steps (i.e. as little as possible) until they are free of defects, ridges, and taper. The final honing should leave the surfaces of the bores honed to the finish specified by the manufacturer of the replacement piston rings.
___C. The deck height should remain at the production height (9.215 inch nominal) unless measurements indicate it needs to be resurfaced.
___D. The main bearing journal alignment should be checked with a straight edge or tested empirically. The empirical alignment is good if the crankshaft can be turned by hand after it has been installed with lubricated new main bearings and after all 5 main bearing caps have been torqued to specification.
___E. The block should be equipped with a neoprene rear main crankshaft seal in place of the OEM rope seal.
___F. The block should be fitted with 16 tappet bore bushings having 0.062 inch orifices (1/16 inch).
10. Replacement of a high mileage oil pump with a new standard volume/standard pressure pump. All production oil pan applications should also be complemented with a factory high capacity oil pump pick-up, Melling p.n. M84-AS1, Milodon p.n. 18635, or Sealed Power p.n. 224-11166. This pick-up was standard equipment in the 351 Cobra Jet and 351 Boss engines (engine codes Q and R).
11. Oil pan choices:
___A. The 351 Cobra Jet and 351 Boss engines (engine codes Q and R) were equipped with a standard capacity production oil pan with a rudimentary sheet steel windage tray spot welded inside.
___B. If the non-windage tray equipped version of the production oil pan (engine codes M or H) is to be used it should be supplemented with an aftermarket windage tray, Milodon p.n. 32220 or Moroso p.n. 22939.
___C. A wet sump racing style oil pan is the choice for cars that shall be subjected to high g-force maneuvers (acceleration, cornering, braking). The oil pan should have 8 to 10 quart capacity and should feature a windage tray, a scraper, and hinged door baffles.
___D. A wet sump racing style oil pan should be standard equipment in the Pantera; Pantera oil pans include Armando p.n. 404, Kevko p.n. 602-400M, or Aviaid p.n. 155-55365.
12. Refurbishment of the reciprocating assembly:
___A. Replace the existing bearings with heavy duty (tri-metal) bearings; the main bearings should be fully grooved (360°). Achieving fully grooved main bearings may require using the upper shells from 2 sets of main bearings.
___B. Main bearing clearance should be set in the range of 0.0025 – 0.0030 inch.
___C. Connecting rod bearing clearance should be set in the range of 0.0023 – 0.0028 inch.
___D. The clearances recommended above are compatible with 10W30, 10W40 or 15W40 motor oil. Motor oil lighter than this (i.e. 0W or 5W) is not compatible with fully grooved main bearings, and it may not be compatible with the hydraulic tappets designed for this 40 year old engine.
___E. If the crankshaft’s end play exceeds 0.010 inch the excess end play can be corrected using a “cranksaver” main bearing sold by King Bearing in the no.3 main bearing saddle. Although King Bearing does not sell a “cranksaver” bearing for the 351 Cleveland, their bearing for Ford’s FE engine drops right in (i.e. the Cleveland and FE engines use the same main bearings).
___F. The crankshaft journals should be checked for defects, taper, and roundness. If they require clean-up they must be ground and polished in specific directions relative to the rotation of the crankshaft when the engine is operating. The crankshaft should be installed in the grinder with the flywheel flange on the left side of the grinder, chucked in the headstock. The journals must be polished after grinding in the opposite direction of grinding so as to most effectively remove the microscopic burrs raised by the grinding process AND to cause the remnants of the microscopic burrs to lay down after polishing in a direction that will not abrade the bearing surfaces when the engine is in operation. The journals should be polished to a finish of 10 micro inches Ra or better.
___G. If the connecting rod bolts are replaced the big-ends must be resized after the new bolts are installed.
___H. Sharp edges on the domes of pop-up domed pistons should be beveled and rounded.
___I. The reciprocating assembly should be dynamically balanced (some machinists call this spin balancing).
THIS STEP IS VERY IMPORTANT.
13. Replacement of any 40 year old OEM crankshaft damper or any "unbonded" replacement damper with a “fully bonded” Power Bond crankshaft damper part no. PB1082SS.
14. Refurbishment or replacement of the flywheel (manual transmission applications):
___A. If the flywheel’s assembled clutch face run-out is 0.010 inch or less, if it has the typical grooves and ridges but can be cleaned up by removal of no more than 0.045 inch material, then a simple resurfacing may suffice.
___B. If the flywheel shows signs of stress cracking or heat checking, if it would require the removal of more than 0.045 inch material to clean it up, if it is warped or has excessive clutch face run-out, then the flywheel should be replaced. A lightened billet steel flywheel is recommended as a replacement. At 26.4 pounds the Yella Terra flywheel p.n. YT9902 is lightest billet steel flywheel known to me. The Yella Terra flywheel is drilled for long style pressure plates like the OEM factory pressure plate.
15. Replacement of a high mileage coolant pump with a new Flow Kooler p.n. 1648 pump.
___A. Replacement of the OEM coolant pump pulley with a 10% over-drive pulley; Pantera applications only. The pulley is available from SACC Restorations.
16. Improvement of the exhaust system.
People do not usually consider an exhaust system as part of an “engine rebuild” project. However the exhaust system is a component in the performance of this “baseline engine” just as raising the compression ratio, improving the carburetion and camshaft selection are.
Headers or exhaust manifolds that are too large in OD, too short in length, or a tailpipe/muffler system that is too restrictive can diminish low rpm torque. The factory exhaust manifolds fit this description, retaining them will diminish the engine’s pep and rob the engine of torque and horsepower. Properly designed steel tubing exhaust headers can add low rpm “pep” to the engine and noticeably harder mid-rpm acceleration, much the same as increasing the compression ratio. Muffler backpressure is an equally big factor in the performance of a street vehicle’s exhaust system. Muffler design is a compromise between sound level, longevity, and its impact upon an engine’s horsepower output. Mufflers which are both quiet and have good longevity normally impact an engine’s output the most. 15 to 80 peak horsepower can be lost or gained depending upon the performance of the exhaust system as a whole.
You are encouraged to select an exhaust system for your car from among those which are commercially available which meets your goals for originality, appearance, quality of construction, performance, sound level, and durability.
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