In reply to EvanB (Forum Supporter) :
Well when you look at big blocks again you have to use the same standard of measurement.
454's of the same era as the Jaguar V12 made 230 horsepower to Jaguars 264* while you may argue that the 454 was about 75 pounds lighter you also must acknowledge the difficulty of working on that engine in that compartment.
The Jaguar engine is only 22 inches wide 24 at the exhaust pipes. spark plugs are on top by the intake manifolds Open the hood of a Jaguar and you won't be able to put your hands past the engine.
Now try to envision changing the spark plugs on a 454. They are down below the exhaust manifolds of a 90 degree engine with much fatter cylinders. As compared to a 60 degree engine with cylinders 3/4 of an inch smaller.
Less typey. More buildy.
You have ME wanting to build one now.
Now envision adjusting the valves
frenchyd said: Now try to envision changing the spark plugs on a 454. They are down below the exhaust manifolds of a 90 degree engine with much fatter cylinders. As compared to a 60 degree engine with cylinders 3/4 of an inch smaller.
Not terribly difficult. IIRC it only took me a half hour to swap the plugs on a 427 'Vette a ways back. Access is extremely easy from underneath.
In reply to EvanB (Forum Supporter) :
Oops I'm trying to reply to streetwise guy.
Anyway, solid lifter overhead camshafts don't require all the adjustment pushrods and rocker arms do.
It's not uncommon for 100,000+ miles to go by before any adjustment is really called for.
When you do adjust valves Jaguar really makes it easy. There is a stud projecting forward on each camshaft that goes into a bracket that holds the Verneer* cam sprocket up so the tensioner doesn't pop out. Hand tighten a 3/8ths fine nut on and as you loosen the two cam bolts
Now you measure the clearances, remove the cam bearing mounts. Lift the cam off and remove the lifters. Using a micrometer measure the thickness and add or subtract until you get back to .012. Grab the appropriate size shim and put it in place.
New shins are marked with thickness but if like me you reuse shims you may need to measure them.
put the lifters back on, the camshaft bearing caps and tighten 15 foot pounds if my memory is correct
align the cam using the cam gauge in your tool kit install the cam bolts. Remove the nut and you're ready to go to the other side.
An hour or two at worst if it's your first time. 30 minutes if you really know what you're doing. I think dealerships really rip you off on this but they think if you're rich enough to come to them•••••••
* Notice I said veneer cam sprocket? That's because it's notched and each tooth allows 2&1/2 degree advance or retard. By reversing the sprocket you can advance or retard it by 1&1/4 degree. Those changes really move the power curve around. If you're racing where peak power is called for or you want to trade bottom end power( say a rainy day ) you can do so quickly right at the track.
Pete. (l33t FS) said:
frenchyd said: Now try to envision changing the spark plugs on a 454. They are down below the exhaust manifolds of a 90 degree engine with much fatter cylinders. As compared to a 60 degree engine with cylinders 3/4 of an inch smaller.
Not terribly difficult. IIRC it only took me a half hour to swap the plugs on a 427 'Vette a ways back. Access is extremely easy from underneath.
A Corvette has a much wider engine compartment.
Streetwiseguy said:
Now envision adjusting the valves
I'll bet I can adjust valves on a V 12 faster than you can change camshafts on a Corvette. ( there are two cams involved on a V12)
Curtis73 (Forum Supporter) said:
Less typey. More buildy.
You have ME wanting to build one now.
Can't, busy helping making Apple sauce. I get a few moments while the cut up apple boil.
