Engine ModifiKation

  • Hello Guys,


    my restoration guy proposed a modifiKation to my engine and i would like to hear your opinion, because i'm not familiar with that modification.
    He said its a standard modification that Shelby did himself.


    It's quite hard to translate it from german to english. If you have trouble understanding it: Please let me know.


    Here's what he wrote: "We will do some fine machining to the valve seats and we will do some adjustments to the transition from the chambers to the manifolds.
    I would give the seats (currently at 45 degrees) a 15 degree refraction angle and i would give a a back cut to the valves."


    He told me that it would cost around 500$ to have it done.


    What do you guys think: Is that something that can be done without lowering the Kar's value?


    Looking forward to your replies.



    Kind regards,
    Niko


  • Niko,


    That sounds like a light port match to the intake manifold and a 3 angle valve job. Unless you are revving to high RPM's in a racing situation, you will actually lose some lower end power due to the slightly larger ports. Being as this does not show externally, your Kars value will not be decreased but you will not gain enough power, even on the upper end to notice it. Keep in mind that Shelby used Tri-Y headers in 1965 and 1966 along with a larger 715 CFM carburetor and high rise intake manifold. Unless you do all of those things, you are just wasting your time. As expensive as these Kars are now, it is too large of a risk to hot rod these Kars today. You might ask Jason (Morsel on this forum) about this as he just lost a couple of rods out of his original VIN stamped engine on his way to a car show.


    -Fred-

    65 Koupe early San Jose Phoenician Yellow 4 speed
    66 GT Koupe Dearborn Blue 4 speed
    66 KGT San Jose fastback pony interior Silver Frost 4 speed
    64 Falcon sedan delivery 289 4 speed
    65 Ranchero 289 4 speed
    66 Corvette roadster 427/425 4 speed

  • I agree with Fred on those points, I would consider installing hardened exhaust seats if you were using unleaded fuel only if you were to disassemble the heads for any reason, other than that let it roll as it is.

  • Quote from chucks302


    I agree with Fred on those points, I would consider installing hardened exhaust seats if you were using unleaded fuel only if you were to disassemble the heads for any reason, other than that let it roll as it is.


    Great suggestion on the hardened exhaust seats, Chuck. I believe that Nikos heads already have hardened exhaust seats as his heads were done when he was touring the U.S.


    -Fred-

    65 Koupe early San Jose Phoenician Yellow 4 speed
    66 GT Koupe Dearborn Blue 4 speed
    66 KGT San Jose fastback pony interior Silver Frost 4 speed
    64 Falcon sedan delivery 289 4 speed
    65 Ranchero 289 4 speed
    66 Corvette roadster 427/425 4 speed

  • Great suggestion on the hardened exhaust seats, Chuck. I believe that Nikos heads already have hardened exhaust seats as his heads were done when he was touring the U.S.


    No, unfortunately they aren't hardened. I told the shop to use hardened seats but they didn't do it.
    And i think that im goona leave it as it is because i bought 100 bottles of lead additive for 1 dollar per bottle.


    Regarding the engine: I sent him your response as he asked me why i wouldn't do it.


    He said that it's a misunderstanding. He wont enlarge the ports. He wants to just "smooth them out" and to adjust the "transition area" and to slightly grind the valve sealing surface. That will make the engine run smoother and give some more power and fuel burning efficiency.


    I don't know if anyone is familiar with that procedure. I'm not but that doens't mean anything.


    Looking forward to your replies.


  • Niko,


    Any of this is an unnecessary expense on your part as you will not notice a difference. You are not trying to build an economy car or an ultra performance version. At least it would not be detrimental to performance as the porting would be and it makes no sense to disassemble your engine for this. You would gain a lot more performance with headers, a larger set of exhaust pipes and mufflers, a larger camshaft and a larger carburetor. Do not forget to change the rods to a stronger version as you will also need to work the engine in a higher RPM range than Ford originally intended. Keep in mind that at only 6,000 RPM your pistons are moving up and down inside your cylinders 100 times per second. As long as the horsepower of the engine is increasing with RPM, you are gaining as you are exchanging that horsepower more times per second to move your Kar forward. All of your internal parts are trying very hard to escape their contained surroundings. Many times they successfully escape and ruin a perfectly good engine which degrades the value of your Kar as they are only original once. If your person feels the need to spend your money for performance, build a different engine and leave your original stored somewhere intact. It is not that expensive to build a higher performance engine compared to trying to replicate an original Hipo 289. You can buy aftermarket heads that will outperform modified Hipo 289 heads for far less money than original Hipo 289 heads. I could go on and on with this, but by now you should understand my concerns.


    Hipo 289 engines are not really known for sinking exhaust valves without hardened seats and your lead additive will be just fine. Just enjoy your Kar as it is the way Ford built it. If you want a hot rod, start with a different car.


    -Fred-

    65 Koupe early San Jose Phoenician Yellow 4 speed
    66 GT Koupe Dearborn Blue 4 speed
    66 KGT San Jose fastback pony interior Silver Frost 4 speed
    64 Falcon sedan delivery 289 4 speed
    65 Ranchero 289 4 speed
    66 Corvette roadster 427/425 4 speed

  • Dear Fred,


    thank you for your post. I agree 100% and his suggestion never felt right to me, even though im sure he knows what he's doing.
    I just wanted to make sure that these modifikations are not necessary and that you would agree with me.


    Kind regards,
    Niko

  • Hey Niko, sorry for the delayed response, didn't see this alert until today. But I think you're getting solid advice here already, and Fred definitely knows what he's talking about, the upgrades you mention don't seem to be worth it in my experience and will not gain you one thing you'll notice while driving the car as far as performance goes.


    And yes, my K engine was completely original with original rods and pistons that were in the car originally. They basically "aged" and we determined that a rod bolt gave way and the whole thing went and blew. Since I'm rebuilding my engine again from ground up, I've decided to use a lot of original items, original cam, lifters, and crank, but the pistons and rods I've decided to "upgrade" to more modern equipment because I definitely do not want this to ever happen again. As Fred said, you will not see this upgrade from the outside and should not decrease value overall unless you are building a thoroughbred, unless you drop the pan you won't notice anything different, but everything from the outside will look and remain original including all the gaskets and such on my Kar.


    As for the heads themselves, I had those done several years back and we kept things original on those except the hardened valves.


    The rest of the items such as exhaust manifolds and pretty much everything else that drives the car is original and before this happened, the Kar was a beast with a ton of power and drove absolutely perfect.


    Hope this all helps a little,


    Jason

    February 10th 1966 - San Jose - Factory GT K-Code Automatic, Candy Apple Red Fastback, Black Standard Interior

  • Regarding exhaust valve seat recession in cast iron cylinder heads, my 2 cents.

    Driven lightly to moderately most of the time I have never heard of any issues with iron cylinder heads and stock Ford valves. Some owners used lead free premium fuel in the 1960s and 1970s, I did from time to time but not exclusively. In period the common wisdom was use some leaded premium occasionally with unleaded fuel most of the time. Lead level content for preignition suppression and lead level content enough to protect the exhaust valves were different subjects. Said another way, you didn’t have to have so much lead in the system so as to produce chalk white insides of tail pipes to protect the valve train.

    Driven at 4,500 rpm and higher revolutions a minute for prolonged periods can under some circumstances cause dramatic recession with stock Ford valves in stock heads. This situation comes up in original Cobras during some long distance tours (750 to 1,300 miles in four days) with 3.77:1 differential gears and rear tires anywhere close to the O.E.M. tire diameter on 25.5 inches for most Cobras. 1965 GT350s with 3.89:1 gears also turn pretty fast on tours and during track days.
    In our red car, depending on exact rear tire diameter in use,

    90 mph is around 4,500 rpm± depending on tires used

    120 mph is around 6,000 rpm±

    132 mph is around 6,500 rpm±

    Engine heat wise five minutes at 6,000 rpm and above is a long time and I have done 30 minutes at a time hitting 8,000 rpm on the straights in open track events.

    We have participate in quite I think eight (8) long tours and there is almost always some spirited driving between 4,500 and 6,500 rpm for more than just short sprints. One of the owners we have toured with participated with have a very near stock engine developed progressively deteriorating performance during one of the western long distance high road speed events. By the end of the event the car would barely run. Upon inspection all the exhaust valve seats deeply recessed. The cylinder head castings and exhaust valves were both damaged.

    I am told by very experienced long term owners that using any brand or alloy of stainless steel or titanium exhaust valves is a solution to the problem. Having hardened exhaust seats installed will solve the problem even with stock 1960s Ford valves.

    We have a car with the valve train Ford installed in February 1964 except for lifters which I replaced at circa 50,000 miles. We use a lead substitute additive in it and have no fear of running it hard as long as I like. Sounds really great above 5,000 rpm. Our other car has modern stainless steel valves and hardened seats. We do not use lead substitute with it and I have no fear of running it as hard and long as I wish. We use to own 1965 MUSTANG GT350. I modified that engine internally including hardened seats and stainless steel valves. I often ran it 6,000 rpm and up on jaunts between towns and up to 8,500 rpm during play for miles at a time. Hardened seats and stainless steel valves were zero problem.

    Summary, from my prospective, with unleaded non-ethanol fuels.

    Engines to be used lightly with occasional short moderate sprints can probably go decades just fine in as built specifications.

    Engines to be used for extended periods of time under high loads and high revolutions per minute probably should be modified. Why risk degradation. (In 2016 we had the engine for a friend's car rebuilt. My friend will probably never run the car very hard or long at one time. I had hardened seats and nice stainless steel valves installed not for my friend but the future of the car. Maybe not in more standard Mustangs but in Cobras, 427 Cobras, and GT350s it is not all that rare for somebody to spend an awful lot for a show quality car and then have it suffer serious engine failure very soon after purchase. Several day tours or open track events find the weak links.)

    Engines with now very rare 1966-65 Shelby American racing cylinder head assemblies, why risk an issue. (You might just roll in and out of a trailer or go to the cars and coffee but the next owner might take the car to a race track or even SAAC convention open track event.)

    Engines with now ultra rare C6FE GT40/Group II cylinder heads from Ford or Shelby, why risk it. (Ditto, maybe not you but a subsequent owner might run the engine hard.)

    Dan

  • Dan, from my observation, it looks like risking the destruction of valuable parts might mean we may never see or hear a proper GT40 perform in earnest again? Or are you thinking that those cars will have a suitable copy of a GT40 head from an aftermarket or even Ford's copy mounted in order to display the performance we so love to witness? My C6FE heads should be reserved for a real GT40 or Comp car, the likes of which I am likely never to never own. where should they reside? on a shelf or on an original engine that sits on display and never runs again? Now what do I do with them? anybody?

  • Quote from HipoDunc


    Dan, from my observation, it looks like risking the destruction of valuable parts might mean we may never see or hear a proper GT40 perform in earnest again? Or are you thinking that those cars will have a suitable copy of a GT40 head from an aftermarket or even Ford's copy mounted in order to display the performance we so love to witness? My C6FE heads should be reserved for a real GT40 or Comp car, the likes of which I am likely never to never own. where should they reside? on a shelf or on an original engine that sits on display and never runs again? Now what do I do with them? anybody?


    Excellent thoughts on your part, Duncan. Personally I am wondering how many owners of original GT40 cars are willing to actually race them in vintage races with original engines?


    -Fred-

    65 Koupe early San Jose Phoenician Yellow 4 speed
    66 GT Koupe Dearborn Blue 4 speed
    66 KGT San Jose fastback pony interior Silver Frost 4 speed
    64 Falcon sedan delivery 289 4 speed
    65 Ranchero 289 4 speed
    66 Corvette roadster 427/425 4 speed

  • Regarding C6FE cylinder head castings, in no particular order.



    Original 1960s castings are not as rare as you might think as Ford made many of them in at least two different versions of casting patterns. Assemblies wise out of the box from Ford and as contractors prepared them for Shelby American they were quite different. The other original race parts for either Group II sedans or GT40s engines are extremely rare in excellent condition.



    Cylinder head matched assemblies prepared by Mondello, Valley, and maybe Rogers for Shelby American in serial numbered matched sets that are still in very good to excellent condition are pretty rare.




    When vintage racing went from a few owners riding around on a pretty day to people running like a national championship was at stake in the late 1970s early 1980s lots of reproduction castings were made for the vintage racers. I talked to a man that advertised them in Hemmings Motor News® back then and he said he had PALLET LOADS of raw castings ready to machined and finished any way buyers wanted. Since then I believe somebody else has made reproductions. (That set of situations made me lose interest in any not traceable back to Ford or Shelby American.) In the early 1980s parts dealers wanted between $3,500 and $6,500 for a pair of new old stock assemblies as Ford sold them. If you wanted to get them fully race prepared you had to do so on your own. When the vintage race replicas hit the market new old stock pair 'value' dropped to not much more than a pair of new old stock HP289 heads. Good used pairs of C6FE head might have been found for less that $800.




    I cannot speak about all 1967 Group II Mustang or Cougars or later GT40 MKIs but at least some don’t want 1960s cylinder heads.



    One of the three Shelby numbered pairs I have purchased or traded for were from a GT40 race coupe owner that wanted a certain pair of modern aftermarket aluminum heads and $600 in trade. That was for Shelby set serial number 5. Joe Mondello’s shop prepared them for Shelby American new and Joe refreshed them for me in 2002. In our hour plus long discussion about my plans for them and how they were to be refreshed Mr. Mondello agreed that hardened exhaust seat inserts should be installed so he did so. We are using them in our red car.



    The typical want advertisements I see posted have been from people racing something in the UK or Europe.



    Us, Dan and Martha, we are using set serial 5 ex-GT40 in our red car. I have not damaged a 289 cylinder head ever even playing at 8,500 rpm in SFM5S142 so I am not concerned.



    PS To get the benefit of full race C6FE heads induction and exhaust systems are required to suit. Some of the Shelby Team heads have seriously enlarged exhaust ports that just any header won't match up to them.


  • Thanks for the insight, Dan.


    -Fred-

    65 Koupe early San Jose Phoenician Yellow 4 speed
    66 GT Koupe Dearborn Blue 4 speed
    66 KGT San Jose fastback pony interior Silver Frost 4 speed
    64 Falcon sedan delivery 289 4 speed
    65 Ranchero 289 4 speed
    66 Corvette roadster 427/425 4 speed

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