C8FE block

[gt350hr]

  Yes. The block was the natural progression from the "289 four bolt main" block made with an XE number. It was considered a "race only" block when it was made. Nothing in the Ford "production car" lineup made enough power to need it. You could not buy one "over the counter" at you local Ford dealer until '69 when it was used for the Boss 302.

[JohnSlack]

Very important history here.

[camp upshur]

XE 289 (attached)

[shelbydoug]

A great discussion that contains important information.

Not intending to be argumentative and I only mention that I read there was a C7FE 289 4 bolt block.

The writer referred to it as a GT40 block. Randy said it didn't exist as such but did as the XE block. Who am I to argue? We do know that writers do make mistakes.

Too bad that so many 69 B2 blocks got damaged by bad broken pistons.


Funny but Randy was so easy to pump for information. It was even better when I made a mis-statement (mostly intentional but not always) and it would just open the flood gates of "corrections".

[camp upshur]

Never heard of nor seen a C7FE block. Would love to see some evidence.

Here is what I've found (and open to editing):
-XE sm block development was a product of the GT40 program;
-1964 used 255 aluminium which cracked block webbing before the trans' went out;
-1965 used basically stock 271hp shortblocks which blew head gaskets and cracked webbing and 325 cid Bechtloff strokers which didn't hold head gaskets;
-1966 used a robusted 2-bolt block C6FE-6015-A, main web cracking. Repros of these enhanced  2-bolt blocks are presently being cast in the UK being used in FIA legal vintage Cobras primarily because they are restricted to a 2-bolt block;
-1967 first 4-bolt block XE-136136 followed by the XE-136505 which is the pic I posted, these engines too were plagued with internal cracking;
-the XE-136505 was integrated into the parts system as the C8FE used for the 302TP and initial Boss production followed by the D0ZE and the D1ZE.
 

-the thin wall 8.2 blocks have notoriously weak block webbing. Today hi-HP SBFs split OEM blocks due to HP (go boom-boom). In yesteryear, such as GT40 LeMans, the engines were low HP by todays stds (375-400 HP 289s, 400-450 HP GW 302s). Today's aftermarket 8.2 blocks have 40+ lbs of iron in the webbing over a 4-bolt Boss block. It's also weight over the nose.
Sustained externally balanced hi-rpm is what killed these blocks in the 60s, not splitting the block, but stress cracking discovered on forensic teardown. How they missed identifying the source for so long is puzzling. I have heard that Hank's 1965 325 strokers were fully counterweighted billets, but have not verified;
-I presently run a D1ZE, but it's risky sustained over 500 hp;
-I have endured the Boss 302 cracked skirts, passive damage, luckily never scored a cylinder.

[shelbydoug]

Never heard of nor seen a C7FE block. Would love to see some evidence.

Here is what I've found (and open to editing):
-XE sm block development was a product of the GT40 program;
-1964 used 255 aluminium which cracked block webbing before the trans' went out;
-1965 used basically stock 271hp shortblocks which blew head gaskets and cracked webbing and 325 cid Bechtloff strokers which didn't hold head gaskets;
-1966 used a robusted 2-bolt block C6FE-6015-A, main web cracking. Repros of these enhanced  2-bolt blocks are presently being cast in the UK being used in FIA legal vintage Cobras primarily because they are restricted to a 2-bolt block;
-1967 first 4-bolt block XE-136136 followed by the XE-136505 which is the pic I posted, these engines too were plagued with internal cracking;
-the XE-136505 was integrated into the parts system as the C8FE used for the 302TP and initial Boss production followed by the D0ZE and the D1ZE.
 

-the thin wall 8.2 blocks have notoriously weak block webbing. Today hi-HP SBFs split OEM blocks due to HP (go boom-boom). In yesteryear, such as GT40 LeMans, the engines were low HP by todays stds (375-400 HP 289s, 400-450 HP GW 302s). Today's aftermarket 8.2 blocks have 40+ lbs of iron in the webbing over a 4-bolt Boss block. It's also weight over the nose.
Sustained externally balanced hi-rpm is what killed these blocks in the 60s, not splitting the block, but stress cracking discovered on forensic teardown. How they missed identifying the source for so long is puzzling. I have heard that Hank's 1965 325 strokers were fully counterweighted billets, but have not verified;
-I presently run a D1ZE, but it's risky sustained over 500 hp;
-I have endured the Boss 302 cracked skirts, passive damage, luckily never scored a cylinder.

It would seem that it isn't the sturdy race level block that we thought it was?

40 more pounds on the nose of a "Mustang" after extensive weight reduction efforts doesn't help anything much?

The thicker "Australian block" in the Pantera doesn't hurt and the Meyer Cleveland block is even heftier then that.

All valuable information to be in possession of.

Now you have me wondering if "main girdles" add enough rigidity to the block also?

[JohnSlack]

Well I don't remember them doing any Cleveland stuff but those guys over at Valley Head Service were epoxying up B2 intake ports way back when the B2 was new to T/A., so other then casting up B2 Heads with intake ports to match 302W's intake ports, I would think that my small port manifold was made with thoughts of cans and cans of Devcon Plastic Aluminum getting put to use? At least experimentlly to try on the flow bench?

I will point out that my intake did come from So Cal. Maybe someone just grabbed it out of the scrap pile? It only cost me $100.

Doug,
Having owned an experimental Dual Dominator T/A intake that Larry Ofria did for Shelby in the day, they used modeling clay. Much easier to remove and add to the ports. I used to work for Larry and took that intake in to show him one day. We discussed the dead air spaces of the ports and intake. Larry had a huge flow bench room. It was still there the last time I went to see him.


John

[JohnSlack]

Never heard of nor seen a C7FE block. Would love to see some evidence.

Here is what I've found (and open to editing):
-XE sm block development was a product of the GT40 program;
-1964 used 255 aluminium which cracked block webbing before the trans' went out;
-1965 used basically stock 271hp shortblocks which blew head gaskets and cracked webbing and 325 cid Bechtloff strokers which didn't hold head gaskets;
-1966 used a robusted 2-bolt block C6FE-6015-A, main web cracking. Repros of these enhanced  2-bolt blocks are presently being cast in the UK being used in FIA legal vintage Cobras primarily because they are restricted to a 2-bolt block;
-1967 first 4-bolt block XE-136136 followed by the XE-136505 which is the pic I posted, these engines too were plagued with internal cracking;
-the XE-136505 was integrated into the parts system as the C8FE used for the 302TP and initial Boss production followed by the D0ZE and the D1ZE.
 

-the thin wall 8.2 blocks have notoriously weak block webbing. Today hi-HP SBFs split OEM blocks due to HP (go boom-boom). In yesteryear, such as GT40 LeMans, the engines were low HP by todays stds (375-400 HP 289s, 400-450 HP GW 302s). Today's aftermarket 8.2 blocks have 40+ lbs of iron in the webbing over a 4-bolt Boss block. It's also weight over the nose.
Sustained externally balanced hi-rpm is what killed these blocks in the 60s, not splitting the block, but stress cracking discovered on forensic teardown. How they missed identifying the source for so long is puzzling. I have heard that Hank's 1965 325 strokers were fully counterweighted billets, but have not verified;
-I presently run a D1ZE, but it's risky sustained over 500 hp;
-I have endured the Boss 302 cracked skirts, passive damage, luckily never scored a cylinder.

It would seem that it isn't the sturdy race level block that we thought it was?

40 more pounds on the nose of a "Mustang" after extensive weight reduction efforts doesn't help anything much?

The thicker "Australian block" in the Pantera doesn't hurt and the Meyer Cleveland block is even heftier then that.

All valuable information to be in possession of.

Now you have me wondering if "main girdles" add enough rigidity to the block also?

Internal balancing of the engine probably does more than the stud girdle. Dralle liked the Pro-Gram Engineering 4340 main caps for the C8FE block more than the girdles.

[pbf777]

Sustained externally balanced hi-rpm is what killed these blocks in the 60s, . . . . .  How they missed identifying the source for so long is puzzling.

Internal balancing of the engine probably does more than the stud girdle. Dralle liked the Pro-Gram Engineering 4340 main caps for the C8FE block more than the girdles.

    This might be getting away from the original topic but, be careful of trying to lay blame for mechanical failures on one door step. 

    Yes, proper balancing can aid significantly in the durability of the block casting, if only with the reduction in vibratory effects which may cause unappreciated movement/motion within the casting material leading to fatigue and fracture.

    Then of course there's the argument of that which might be construed as a "proper" execution in the endeavor; most importantly where the counter-weight masses are to located on the revolving crankshaft, assuming that all of the other considerations are fixed.  We often reference "internal" and "external" as determining factors in proper and improper executions, and I suppose in simple observation and consideration this probably will hold true; but even so, may only prove to be a minor player in the actual multiple causes that lead to failure in the block casting.

    Without getting into long, drawn-out discussions of crankshaft construction, probably the significant concern of external counter-weighted crankshafts would be that external mass, unsupported as not bridging two mains locations; the consideration being whether the crankshaft is capable of supporting the cantilevered mass as acting off-centered on the rotation creating a lateral load sum.  If such were so, then there would be far less concern for this type of presentation.  Therefore we have opened the door to the thought of: is it perhaps that the crankshaft just isn't rigid enough; this regardless of where the counter-weighting might be positioned? And although the external counter weighting certainly 'temps' fate, there have been instances where when taking into consideration other circumstances, it proves to be the 'best' option. 

    Remember, there's a basic engineering problem in the "V" configured engines, this being that forces acting upon each bank of cylinders is pushing and pulling on the crankshaft and the block acting and reacting at different planes of motion, and it is the responsibility of the each to be capable enough that neither presents excessive load responsibility upon the other. 

    Scott.         

[camp upshur]

Scott,

Thank you. Not untrue.

It is my belief that the main web structure/ stress cracking was the effect of the problem, not the cause.

From the effect I would think one would work backwards, especially when a damaged passive piece (such as a block) houses dynamic pieces and their incumbent oscillatory harmonics (such as both a rotating and reciprocating assembly under varied loads and speeds).

A sporting rhetorical question:  the orientation of the axis of the application of their engineering discipline, that's all  .

In my former career we would often simply say: 'what were they thinking ?'.

-Steve A

[pbf777]

It is my belief that the main web structure/ stress cracking was the effect of the problem, not the cause.
From the effect I would think one would work backwards, especially when a damaged passive piece (such as a block) houses dynamic pieces and their incumbent oscillatory harmonics.

    Oh, I don't disagree, and that was my point (though perhaps poorly presented  ), as obviously one would want to start with the component that actually failed; but obviously the block just didn't fail solely of its' own doing.   

In my former career we would often simply say: 'what were they thinking ?'.

    In my opinion, I think "they" had thought it out pretty well actually. Not that anything was new as for that associated from the engineering standpoint and we must keep contemplation of in period and tempered with an understanding of production requirements.  But obviously given the rather lengthy lifespan that the S.B.F. engine provided, establishing a good rapport with users in many different service applications along the way, I have to think that this engine series should rank as one of the "great" engine executions in American V8 history.    

    Now, when 'we' in the racing world, decide to take something "engineered" by the O.E.M.'s for an intention quite different than that which 'we' now intend to press it into service for, and then experience failures, these not being typical of these units, as a matter of fact quite the opposite, that of in their intended applications, we might want to reflect on 'whom' the statement might better apply; perhaps this might be more applicable as: "what were "we" thinking!"   

    Scott.

[JohnSlack]

It is my belief that the main web structure/ stress cracking was the effect of the problem, not the cause.
From the effect I would think one would work backwards, especially when a damaged passive piece (such as a block) houses dynamic pieces and their incumbent oscillatory harmonics.

    Oh, I don't disagree, and that was my point (though perhaps poorly presented  ), as obviously one would want to start with the component that actually failed; but obviously the block just didn't fail solely of its' own doing. 

In my former career we would often simply say: 'what were they thinking ?'.

    In my opinion, I think "they" had thought it out pretty well actually. Not that anything was new as for that associated from the engineering standpoint and we must keep contemplation of in period and tempered with an understanding of production requirements.  But obviously given the rather lengthy lifespan that the S.B.F. engine provided, establishing a good rapport with users in many different service applications along the way, I have to think that this engine series should rank as one of the "great" engine executions in American V8 history.   

    Now, when 'we' in the racing world, decide to take something "engineered" by the O.E.M.'s for an intention quite different than that which 'we' now intend to press it into service for, and then experience failures, these not being typical of these units, as a matter of fact quite the opposite, that of in their intended applications, we might want to reflect on 'whom' the statement might better apply; perhaps this might be more applicable as: "what were "we" thinking!" 

    Scott.

Scott understood the Packard Merlin engine was rated @ 1,380 HP with a 500 hr life on the top end and a roughly 1,000 hr. Life on the bottom end (really 800 - 900 hrs.) when we started developing 3,800 HP on the engine it had a 45 minute fuse. As you increase the load things change.