Engine change

Is your current engine stock or have modifications to it? Answer will also depend on how much you want to spend. You would be well served by having your current engine checked out first by a good mechanic. I'm sure you'll get some responses to your question here but also do some searching thru archived posts. You shouldnt have to sink TOO much to reach 400 ponies w/ current engine if its ok.

I'm the second owner, bought the car in 1976, and as far as I know the engine is stock.

If it were my money (I'm pretty good at spending other people's money :-) ) I'd wait until I had a reason to rebuild the motor before rebuilding it.

Since you are questioning buying new vs. rebuilding, perhaps my case could be helpful. I broke a valve spring with only 35,000 miles on the engine, so I replaced the spring. I broke another one 6 months later so I replaced the heads, going with Aussie closed chamber heads. While I was at it, I rebuilt the upper end. The heads weren't assembled correctly, and I bent pushrods and destroyed roller rockers every 500 miles. As a result, I had to go through a COMPLETE rebuild again. I think I have my problems solved now, but I would have been big time $$$ ahead to have bought a brand new crate motor instead of piecemealing my engine.

If you replace or upgrade just one part, the rest of the engine still has wear and miles. Therefore if you are going to rebuild, spend the extra $$ to replace everything worn, do it once, and do it right.

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Charlie McCall
1985 DeTomaso Pantera GT5-S #9375
"Raising Pantera Awareness across Europe"
http://briefcase.yahoo.com/gt5s_1985

With a stone-stock 351-C & 50K miles, the engine desperately needs a new timing chain and a valve job, this last partly to to remove whats left of the stock umbrella valve stem seals. Stock neoprene seals rapidly deteriorate into hard plastic that crack, wash down into the pan and jam the oil pump. Note that all Ford engines run just fine with a broken oil pump drive.... for maybe 2 minutes. The stock timing chain often wears out in 20K miles on a 351-C with those enormous, heavy valves. It should be changed to a much stronger roller-type chain; this will allow your mechanic to reset the cam to straight-up timing. Ford was forced to retard the cam 4 degrees in '72 for smog. You'll be surprised what these 3 things will do for your better-than-new engine, at low cost, without having to remove the engine. But a general overhaul will allow you to clean 31 yrs of crud out of your stock oil pan, too. If you do this, I suggest adding a removeable rear crossmember to the car so the pan can be dropped next time without pulling the engine. All these were incorporated into factory Panteras after '74, if you want it to remain "stock". I'd also recommend adding a baffled 10-quart pan to ANY Pantera running modern tires. Incidently, Charlie McCall had his misfortunes while living in Europe, but it points up the absolute necessity of finding a knowlegable FORD mechanic! Chevy specialists and others will be learning on your engine, at maybe $75/hr plus parts.....

Charlie,
You refer to a crate motor. What type are you refering to? Where can I pick one up? Any information would be appreciated.Thanks.

SVO Ford deaers advertise 375-horse 351-W 'crate' motors for $3795, complete except for intake manifold and carb/air cleaner. They are in all the Ford enthusiast magazines including Hot Rod.. Note that you have some adaption to do with this engine, as the Panteras AC/alternator bracket will not bolt on, the headers don't fit and you may have a few water and electrical hookup issues as well. Better would be a Windsor short-block, to which you adapt your stock Cleveland heads, a custom intake manifold. Then, with a few mods, the stock Pantera headrs will fit. This is what used to be called a "Street Boss" engine back in the '70s.

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Originally posted by jack deryke:
Stock neoprene seals rapidly deteriorate into hard plastic that crack....

The stock timing chain often wears out in 20K miles on a 351-C with those enormous, heavy valves. It should be changed to a much stronger roller-type chain; this will allow your mechanic to reset the cam to straight-up timing. Ford was forced to retard the cam 4 degrees in '72 for smog....

..., I suggest adding a removeable rear crossmember to the car so the pan can be dropped next time without pulling the engine....

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Jack, sorry for pulling out parts of your post and calling them "quotes," but I wanted to focus on three (3) questions:

(1) My mechanic said he can change the neoprene seals without doing the entire valve job by using special tools and pressurizing the valves, reducing significantly the labor and cost. His thinking was because the engine is really strong already and not smoking or showing any other signs of fatigue, there is no need to do a valve job, with the associated expense. Ever heard of this procedure? Any opinion?
(1)(a) My mechanic said his machine shop owes him some favors, and he owes me some favors, so if I elect to do the valve job, he can get me my choice of free porting or free polishing. Can you give a recommendation in this regard please? Which is better given a choice. I want relaibilty 1st, power 2nd, mileage 3rd.
(1)(b) My 351-C is not pinging on local high octane, but he said we could get the hardened valves or valve seats for pretty much the same cost. I am not sure what all this means, or whether it is worth it. Any clues you can provide will be appreciated.

(2) I sort of understand that there are three (3) positions the cam/valves/roller timing chain can be set at. 4 degrees retarded as per the factor after 1972, straight up, and 4 degrees advanced. I read that 4 degrees advanced will result in straight up valve timing after the chain stretches after the break-in period. He said the double roller timing chains stretch very little. I'm wondering what is the difference if I go with a double roller timing chain and straight up timing or with four (4) degrees advance. Suppose I go four (4) degrees advance and the chain does not stretch as much as I thought? What will the engine run like? What's your recommendation?

(3) A Pantera guy who's owned four (4) Panteras said he 'made his own' removable engine cross-member. Can you tell me how this is done, please.

Thank you. My mechanic was impressed that I asked these questions and asked a lot of questions about you. Which, of course I only know what I've read, so that's what I told him. He's impressed. Been a mechanic for 26 years, worked for dealerships, self employed, small shops, big shops, $250,000 in tools. He was impressed. Kudos, Jack!

Q#1- sure, the umbrella seals can be swapped out for real seals without removing the heads, by using an air-cuck in the sparkplug holes, or feeding rope inside to keep from losing control of the valve during seal changes. Quite a bit of work on a Pantera with its restricted access to the heads, though. The main thing is to get all neoprene out of the rocker area before the bad stuff happens. Your guy could easily run a leak-down test that will pinpoint exactly how good the engine is sealed, and note where & how bad any problems are. I love leak-down tests!
#2- don't bother either porting or polishing 4-V heads. The stock intake ports are so huge that any material removed only makes throttle response that much worse, unless you are racing for money.Polishing reduces port-turbulence which will also mess with throttle response and maybe mixture. Remember, 4V ports & valves in the 351 C are almost identical to those now used by Ford 460 engines....
#3- I wouldn't worry about hardened seats in iron-head Clevelands, unless these heads have sunken seats already from multiple valve jobs or,had bad corrosion in valuable closed-chamber heads from sittng open in a junkyard for a long time, or you intend to convert to propane which is an extremely 'dry' fuel that will erode seats. The only engines that showed significant valve seat regression in testing were long-haul truck motors that average maybe 250,000 miles a year. Most Panteras will NEVER get that kind of mileage let alone in a year, so hard seats are expensive overkill IMHO.
#4- the effect of a cam running retarded is, you get a lttle more low end under acceleration so some builders do this intentionally. A stretched chain is bad not necessarily due to this but the fact that it indicates wear and can easily jump a tooth or ten, making the engine inoperable in an instant. I like cams set to advanced since, set straight-up (after initial wear in), the engine has adequate low end plus better top end. Some cams respond better to this manipulation than others, but I got the idea that you simply want the thing to run well on the street. So virtually any way its put in will result in a good running street motor.
#5- I cut the OEM spot-welded crossmember out of the frame and welded up a piece of thickwalled pipe with a flange on each end that was a slip-fit in the old space. In each flange, I cut a slot 1/2" wide about half-way up. This allows the front lower rear a-arm nut to hold the new crossmember in place, and makes it easily removeable if you wish to drop the oil pan for inspections or work. The pipe will also need a cut-out for box-end-wrench clearance for tightening/loosening the big nut at each end. The factory took the stock crossmember & welded flanges on it in 1975. Along with this mod, the e-brake bracket ahrad of the engine will need to be cut loose, an angle-iron added to the cut edge, then some large self-tappng bolts will hold this bracket in its stock position but will be removeable. The oil pan moves fwd a bit, hitting the bracket, during pan removal. A 10-qt pan should be a must on any Pantera running modern tires, incidently. I saw an otherwise stock Pantera with gumball tires at a track event wipe 100% of the rods & main bearings out in only 4 laps. Many savvy 351C engine builders will not install an engine in a Pantera without such a pan, simply from liability concerns.

Jack,
After reading your various replies, I am now convinced not to try and install a new engine but, to upgrade the stock 351C engine presently installed. As such, would you please advise me with your recommended modifications I need to have done on a 50K engine to achieve around 400 horses. Keeping in mind street driveability first, dependability second and milage last.Your specific recommendations would be appreciated. Thanks.

If I was to rebuild a stock 351-C tomorrow, this's what I'd do:
1)- add a mild cam, new hydraulic lifters, new valve springs, all from the same cam grinders recommendations, plus new Boss 351 hardened pushrods, single-groove one-piece stainless valves, with keepers to match. Stock valves are made in two pieces, friction-welded together. Moderate performance and old age can cause them to be two-piece again, utterly destroying the whole engine. Note- if the ad for valves does not specifically SAY "one piece", they aren't, whether or not they're stainless. Stock valves also have multiple grooves to hold them, and the multi-groove keepers do NOT hold the stems tight. Instead, they wobble a little which supposedly makes valve jobs last longer. It also allows an occasional valve to escape, again totally destroying the engine.
2)- rebuild the connecting rods to the small side of bearing tolerance, using Boss rod bolts & nuts. Stock rods use 'football-head' bolts which are a little weaker than stock Boss bolts with angular wedge-shaped heads. Cost is the same for either.
3)- I'd have someone carefully measure the cylinder bore taper, and if it was less than 0.005", I would have a good shop HONE the cylinders straight, not bore them. Then, I would use forged standard-bore pistons and good rings in the slightly oversized bores.Forged pistons are stronger than all cast pistons and expand more during warm-up, so the 0.005 (max) clearance works just fine, if a little noisy at start-up. Clevelands have too thin cylinder walls to withstand 030-ovebores unless you sonic-test the block prior to boring. Even then, its iffy- on a competition block running 13-1/2: 1 compression, the engine 'sneezed' on pregrid. A single 60-second run had water pouring out one tailpipe. A trailer ride home & teardown showed a piece of cylinder wall the size of a 50� piece blown into the water jacket from the little backfire. The wall at that point was only 0.070" thick, far too thin to withstand any performance mods, due to having been overbored 0.030" during overhaul. Point: do NOT bore a Cleveland AT ALL, unless its been sonic-checked. Blocks are getting scarce....
4)- add a 10-qt Aviaid oil pan. Don't rationalize it, just do it. It is insurance
5)- add a Milodon or SVO-Ford hardened oil pump driveshaft, and double-pin the distributor drive gear on whatever distributor you choose to run. More insurance. A stock oil pump is fine.
6)- add a nice Holley carb, NOT a double-pump type, of between 600-750 cfm capacity, on an Edelbrock Performer intale. A 600 carb will have better throttle response and be better in around town driving. It will also outperform the 750 on a normal autocross course. The 750 will give roughly 35 more horses, will give less crisp throttle response and will give 4 mpg less fuel mileage. Your choice here.
7)- freshen up the dual-points distributor including new bushings in the body, or add a Ford electronic ignition system, new wires etc. Early Ford 460 electronic distributors are drop-ins for 351-Cs but will benefit from being recurved from a truck ignition curve to a performance one. The Pantera vendors routinely do this.
8)- use a Weiand aluminum water pump, and add the impeller back-plate to increase pumping capacity. This unit blocks off the warm-up passage in the 351C block, but also allows one to run any Ford thermostat you choose, not just the specific 351C unit, which is also getting had to find. It will take 2 extra mimutes to warm up in cold weather, but will probably lower your cruise water temps by 15 or more degrees.
9)- if your budget is not blown yet, I'd also add full roller rocker arms and a Crane conversion kit to allow an adjustable valve train. The rollers are dependable but do not add power. Instead, they add reliability and drop the loaded oil temperature by 10-15 degrees, always a good move in a car with heating issues such as the Pantera.
10)- finally, I'd use 10-12 degrees initial timing advance, not over 36 degrees total advance and I'd check it monthly until I had a thousand miles or so on the engine.
This is a basic description of my current engine, built in 1989 and still running well, no oil issues and enough power to push us, two-up with a weeks baggage, to 150 mph for 10 or so minutes at a time, not just for an instant.I'm still satisfied.

Jack,
You are amazing for taking the time and effort in helping me and probably many others with a similar dilemma. Any idea on how much all of this may cost and how do I find a reputable individual or shop, preferably in the midwest, that would follow your recommendations to the letter. Collectors Choice in Wisconsin is out of the question. Please advise. Thank you.

First, I entreat you to join anactive Pantera club. If they have no suggestions as to where to go, and you have little experience in engine building, I suggest you go to a Ford specialist for the machine & assembly work. Most rebuilders are Chevy specialists, and the 351-Cleveland is sufficiently different that their mistakes will be very costly- to you! There are many Ford builders all over the country, but if you live in the Midwest (you referred to Gehling's Wisconsin operation), you might start by asking around the pits at sprint-car rases as to who's running Fords, and find out who builds their stuff. The Pantera is a somewhat specialized varient of the 351C, so failing all this, start e-mailing the various vendors in your Pantera newsletter or P.I's magazine. They will sell you a 'crate' engine (complete except for carb & headers) or a short-block (block, pistons crank & bearings) with your motor as a core, or (better) you can keep your original block & crank for a leisurely rebuild yourself over the next few years. Pulling the engine and reinstalling it can actually be a fun weekend job if you join a local Pantera club that has motorheads that will come over & help you, bringing their tools etc. My POCA chapter in N. CA went to a members house one rainy Saturday morning and swapped his engine, transaxle and gas tank in 8 hrs while he (afflicted with severe arthritus of the upper spine) kept a pot of chili hot and a case of beer & soft drinks cold. We all had fun & he got his Pantera troubles fixed (including two he didn't even know he had!). Other clubs have done likewise. We're all one more-or-less-happy family in Pantera-ville! Where exactly do you live?

Jack,
I live in a suburb of Chicago.

Living in a Chcago suburb, you need to know Dave Doddek from Decatur and president of Great Lakes Panteras (pantera@pobox.com). Dave does most or all of his own work, and has been known to drive 2 hrs one way to help someone in te club change intake mainfolds and calibrate aftermarket fuel injections. Dave's car is a twin-turbo injected 351C. He managed to drive to & from Las Vegas for the national convention, twice, stopping at the Silver State open-road race one time. The trips were over 5000 miles apiece, so he does build good engines. Talk to him-

Jack,
Thanks for all your help. I will try and contact Dave.

Jack, I have been following this thread pretty carefully given that I have to perform some of these upgrades soon. I have a couple of questions I would like to tag on.
1. Is the valve job that you suggest above pretty much just a standard valve job with new, one piece valves, etc. Are there any additional special directions?
2. Should new valve springs be single or dual coil?
3. Crane produces a cam for this engine that is between the duration specification of 194-214 @ .050. Is this the sort of mild upgrade that you would suggest for a street engine?
3b. With the heads off, is it possible/advisable to install the new cam with the engine still in the car?
3c. I'm familiar with roller rockers but don't know the function or purpose of a fully adjustable valve train. Can you explain?
4. After making the cross member removable, can the Aviaid oil pan be installed from below?
5. Can I replace the oil pump from below?
6. Does Weiand produce the impeller back plate. I don't see it in their catalog.

Thanks for all of your help.

Joel

1)- A std 3-angle valve job, carefully done, will be fine. I like all-teflon valve stem seals, too. This may require the tops of all the guides to be slightly cut down so the seals will fasten on. Stock seal aren't really seals as they ride up & down with the valve and keep oil fron cascading down into the guides which results in one type of oil burning. They are called 'umbrella-seals' for that reason.
2)- Aftermarket valve springs will always be an inner round, an outer round and a flat damper. The reason I suggest asking the cam grinder who makes your cam is, they know what works with their cam. Trying to assemble the parts otherwise may or may not work out and will surely be chancy if not more expensive. All the grinders have a Tech Line for any questions.
3)- a 351-C is really a short-stroke big-block in the manner in which it reacts to camshafts, and big blocks need LOTS of cam! I run a mild SVO-Ford hydraulic-lifter cam (p/n M-6250-A331) that is 221� (I) 225�(Ex) degees@0.050 lift, with a 0.510/.536" lift height. With a 351-C, this is a mild grandma- type street cam that passes CA smog tests. In a smallblock Chevy, it would be considered a serious race cam. The Crane cam you note is more of the type cam you'd run in a towtruck.A stock 351C cam was never specified by the 0.050"lift std, but I suspect it was more radical that this Crane.unit
3b)- Its easy to install a cam with the block in the car. If the heads are on too, you need to remove the rocker covers, rocker arms & pushrods, water pump and the intake.
3c)- the stock valvetrain (except for the Boss 351) has the rocker pivots bolted solidy to the heads, so no adjustements of any kind can be done. With adjustable rocker pivots, the clearance beteeen the valves and rockers can be set, or with hydraulic lifters, the amount of depth the hydraulic piston is pushed down iside the lifter can be varied. The hardened steel guide plates that control the pushrods (which also must be hardened or you'll saw then in two). In the case of the Crane kit I mentioned, their 'guide plate' uses a slush-molded Kevlar grommet, so unhardened pushrods can be used. But the Boss pushrod is slightly longer and does good things for your valvetrain geometry even if you choose not to use the hardness.
4)- making the rear crossmember removeable is the point; the crossmember can then be removed, allowing any oil pan to be removed or reinstalled. But you also must make the bracket mounting the e-brake bellcrank removeable as well, because pans move fwd while being unboltd and any pan will run into this bracket, preventing easy removal.installation of a pan. The Aviaid fits exactly like a stocker Incidently, there are three 'stock' type pans possibly on any 351-C, that range from crummy to mediocre IMHO
5)- the oil pump and its driveshaft can be accessed or replaced from below. The Aviaid pan has its own pick-up that attaches to a stock oil pump, and its a little more tricky to manuver the Aviaid around its inner shields and splash- guards, but with the crossmember and e-brake bracket unbolted, it can be done.
6)- No, but someone makes such a thing that fits, sold through Summit Speed Shops and probably other sources. It attaches by means of stainless-steel pop-rivits (hardware-store aluminum rivits will quickly fail, by the way), and getting the backplate in place so its centered before you drill, is critical or things will be slightly off-balence. But it can be done, at home, with hand tools. And its cheap.

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Originally posted by jack deryke:
6)- No, but someone makes such a thing that fits, sold through Summit Speed Shops and probably other sources. It attaches by means of stainless-steel pop-rivits (hardware-store aluminum rivits will quickly fail, by the way), and getting the backplate in place so its centered before you drill, is critical or things will be slightly off-balence. But it can be done, at home, with hand tools. And its cheap.

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Jack, are you talking about the FLOW KOOLER Impeller Disk that attaches to the back side of the water pump's impeller, part # BRA-3875-03 $5.95, Summit catalog, p. 155, w/pricing effective thru 8/31/03?

Also, I didn't see "high flow" Weiand water pumps, on the same page in Summit, but noticed Collector's Choice, one of our Pantera Vendors, advertising a 351c aluminum HiFlow water pump for $10 more than Summit's price on Weiand water pumps and thought I'd get one from Collector's Choice, if it is a Weiand, and especially if it's got the impeller disk installed already (if that's the backing plate you mean). The new Pantera Int'l issue has the ad on p. 27, and I always like to help keep Pantera Vendors in business. Does the picture on Pantera Int'l p. 27 look like the Weiand water pump on your and Mrs. DeRyke's Pantera?

(Read your article on pp. 60-61 and I'm gonna do your recommendations not already performed. Thought I better give your wife mention as it was "HER" Pantera, well, sorta', guess you other guys may wanna read Jack's great article, a little history...)