Edification Required SP6 & AJP8
Discussion
As I seem to be poorly informed regarding the history of these (and the 7-12) engines, I am hoping that some of you can shed some light on a few issues.
1.) Who designed what on any/all of these engines?
2.) Who or what caused the delay that left all but one Griff Olds/Buick/Rover powered?
3.) Was the SP6 a Ravenscroft clean sheet design or was it based on the AJP8? If it was a re-development, what (obviously on the bottom end) was different?
4.) After all this time, reading threads relating to the problems with these engines it seems as though nobody can point their finger at their exact failure point(s). Do the engine builders not accuse particular broken bits?
What parts fail? Is it he interface between the cam and the finger followers? Why? Has anybody done an analysis on the factory cam and follwers and found them to be of the correct hardness? If there is a problem with the angle at which the followers act on the valve, you would expect to see premature wear at the valve stem/guide.
5.) If AM designed the AJP8 and JR designed the SP6 and the 7-12 is a billet version of the doubling-up of two SP6 engines, why is AM so often credited with the design of the 7-12?
6.) Can I read a book on all this?
Thanks in advance for only posting if you are certain. There are already too many rumours flying around.
Also, I would be very grateful if you could include the source of the information.
BH
1.) Who designed what on any/all of these engines?
2.) Who or what caused the delay that left all but one Griff Olds/Buick/Rover powered?
3.) Was the SP6 a Ravenscroft clean sheet design or was it based on the AJP8? If it was a re-development, what (obviously on the bottom end) was different?
4.) After all this time, reading threads relating to the problems with these engines it seems as though nobody can point their finger at their exact failure point(s). Do the engine builders not accuse particular broken bits?
What parts fail? Is it he interface between the cam and the finger followers? Why? Has anybody done an analysis on the factory cam and follwers and found them to be of the correct hardness? If there is a problem with the angle at which the followers act on the valve, you would expect to see premature wear at the valve stem/guide.
5.) If AM designed the AJP8 and JR designed the SP6 and the 7-12 is a billet version of the doubling-up of two SP6 engines, why is AM so often credited with the design of the 7-12?
6.) Can I read a book on all this?
Thanks in advance for only posting if you are certain. There are already too many rumours flying around.
Also, I would be very grateful if you could include the source of the information.
BH
Slow M said:
As I seem to be poorly informed regarding the history of these (and the 7-12) engines, I am hoping that some of you can shed some light on a few issues.
1.) Who designed what on any/all of these engines?
2.) Who or what caused the delay that left all but one Griff Olds/Buick/Rover powered?
3.) Was the SP6 a Ravenscroft clean sheet design or was it based on the AJP8? If it was a re-development, what (obviously on the bottom end) was different?
4.) After all this time, reading threads relating to the problems with these engines it seems as though nobody can point their finger at their exact failure point(s). Do the engine builders not accuse particular broken bits?
What parts fail? Is it he interface between the cam and the finger followers? Why? Has anybody done an analysis on the factory cam and follwers and found them to be of the correct hardness? If there is a problem with the angle at which the followers act on the valve, you would expect to see premature wear at the valve stem/guide.
5.) If AM designed the AJP8 and JR designed the SP6 and the 7-12 is a billet version of the doubling-up of two SP6 engines, why is AM so often credited with the design of the 7-12?
6.) Can I read a book on all this?
Thanks in advance for only posting if you are certain. There are already too many rumours flying around.
Also, I would be very grateful if you could include the source of the information.
BH
I search on here would cover a lot of those questions, if you have the inclination. 1.) Who designed what on any/all of these engines?
2.) Who or what caused the delay that left all but one Griff Olds/Buick/Rover powered?
3.) Was the SP6 a Ravenscroft clean sheet design or was it based on the AJP8? If it was a re-development, what (obviously on the bottom end) was different?
4.) After all this time, reading threads relating to the problems with these engines it seems as though nobody can point their finger at their exact failure point(s). Do the engine builders not accuse particular broken bits?
What parts fail? Is it he interface between the cam and the finger followers? Why? Has anybody done an analysis on the factory cam and follwers and found them to be of the correct hardness? If there is a problem with the angle at which the followers act on the valve, you would expect to see premature wear at the valve stem/guide.
5.) If AM designed the AJP8 and JR designed the SP6 and the 7-12 is a billet version of the doubling-up of two SP6 engines, why is AM so often credited with the design of the 7-12?
6.) Can I read a book on all this?
Thanks in advance for only posting if you are certain. There are already too many rumours flying around.
Also, I would be very grateful if you could include the source of the information.
BH
As an example, the Melling thread created recently mentions there was an original AJP6 in Al's workshop (from which the Speed 6 has derived).
However, lots of this has been done to death, so getting everyone to pick the bones out of old threads to answer you questions is asking a lot IMHO.
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