Anyone familiar with these claimed 620hp heads item# 2435998693
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quote:
Originally posted by kenf:
Anyone familiar with these claimed 620hp heads item# 2435998693
I ordered a set in oct, should arrive in "2-3 weeks", still waiting ,now by the end of jan I'am told.
doesn't sound very promising
Now new heads should come in early feb. I will keep you posted.
quote:
Originally posted by Wes Jones:
Now new heads should come in early feb. I will keep you posted.
Friday the 13th . THE HEADS HAVE ARRIVED!
They look nice, have to see what my head guy says about them.
quote:
Originally posted by AGROVADR:
doesn't sound very promising
Engine builder is impressed with the heads.The valves needed to be .100 longer to allow me to use the springs I needed. I should have them on my engine soon and off to the dyno!I will let you know how they work there.
quote:
Originally posted by kenf:
Anyone familiar with these claimed 620hp heads item# 2435998693
Can you let us know who produced them and how they are working out.
Thanks!
If these are the Aussie-produced aluminum heads now marketed by the owner of this page, they are probably quite similar to SVO. As has been published numerous times, the bare heads are about half the expense of adding them to your Pantera. As you found, the valve stems need to be longer- the mounting bolts or studs do, too as the castings are physically thicker. I also suggest valves that are single-groove rather than the looser multi-groove type which are known for failing at high engine speeds. Valve springs cannot sit directly on the aluminum head so you need steel valve spring cups of a size to fit both springs and the machined head pockets. The heads require valve guide plates (sometimes of custom shape), which then requires hardened pushrods that rub on them. Std steel pushrods will be sawn in half within 1000 miles & the grindings spread throughout the engine. I'm not familiar with those heads so the pushrod length needed may be non-stock, too. Head gaskets should be composite- Fel-Pro supplies teflon coated ones as there's some relative motion between aluminum heads & a cast iron block. Never use steel-shim gaskets or the heds will be dented during torquing. The combustion chambers are closed type so you need to accurately measure your short-block's compression ratio or you may be saddled with using racing-gas or worse- mechanical interference that cracks a piston. I certainly recommend stronger forged pistons for high compression use (over 9-1/2:1). If these things have alterd port positions for better efficiency, the stock headers may run into the gas tank and the rear suspension, forcing custom headers & exhaust. Stock-type intakes may not fit either and certainly take different gaskets. The carb & air cleaner may interfere with the engine screen and/or the decklid edge. Rule of Thumb- a pair of $1000 aluminum head castings will cost another $1000 for the rest of the assembly. If you got them fully assembled AND cheaper- congratulations. Their main value is the 60+ lbs less weight per pair, the fact that they don't hot-spot at high compression like iron and the total repair-ability by TIG welding if things don't go according to plan....
I don't believe the heads are the ones you are talking about. these heads have stock locations fot the intake and exhaust ports. the reason I needed longer valves is because the installed spring height was at 1.800 and I needed 1.900 for my springs. I have a mechanical roller with 6.500 net lift. The guide plates are stock items, the pushrods came out to be 8.450. the studs were from comp cams, they needed to be shortned .500 to all the lock nut to work correctly.These heads have a 60cc closed chamber. the ports have been reshaped, but still in the stock location.I put these on a 383 stroker block with 18cc dish pistons, 9.85cr. The piston to valve clearence was .185 on the intake and more on the exhaust. I started the engine on a stand today, will be at the dyno on the 31st or march.
quote:
Originally posted by jack deryke:
If these are the Aussie-produced aluminum heads now marketed by the owner of this page, they are probably quite similar to SVO. As has been published numerous times, the bare heads are about half the expense of adding them to your Pantera. As you found, the valve stems need to be longer- the mounting bolts or studs do, too as the castings are physically thicker. I also suggest valves that are single-groove rather than the looser multi-groove type which are known for failing at high engine speeds. Valve springs cannot sit directly on the aluminum head so you need steel valve spring cups of a size to fit both springs and the machined head pockets. The heads require valve guide plates (sometimes of custom shape), which then requires hardened pushrods that rub on them. Std steel pushrods will be sawn in half within 1000 miles & the grindings spread throughout the engine. I'm not familiar with those heads so the pushrod length needed may be non-stock, too. Head gaskets should be composite- Fel-Pro supplies teflon coated ones as there's some relative motion between aluminum heads & a cast iron block. Never use steel-shim gaskets or the heds will be dented during torquing. The combustion chambers are closed type so you need to accurately measure your short-block's compression ratio or you may be saddled with using racing-gas or worse- mechanical interference that cracks a piston. I certainly recommend stronger forged pistons for high compression use (over 9-1/2:1). If these things have alterd port positions for better efficiency, the stock headers may run into the gas tank and the rear suspension, forcing custom headers & exhaust. Stock-type intakes may not fit either and certainly take different gaskets. The carb & air cleaner may interfere with the engine screen and/or the decklid edge. Rule of Thumb- a pair of $1000 aluminum head castings will cost another $1000 for the rest of the assembly. If you got them fully assembled AND cheaper- congratulations. Their main value is the 60+ lbs less weight per pair, the fact that they don't hot-spot at high compression like iron and the total repair-ability by TIG welding if things don't go according to plan....
The dyno session went well. The 383 ci cleveland produced 509hp at 6100rpm. The torque curve wasn't much of a curve at all it was at 400 to 470 from 3500 to 6100rpm.The dyno guy said that he doesn't see many 500hp small blocks with unported heads and pump gas.The total ignition timing was at 34 degrees which he said means the combustion chamber is designed very good . I am very happy with these heads, e-mail me if you have any questions.
quote:
Originally posted by Wes Jones:
I don't believe the heads are the ones you are talking about. these heads have stock locations fot the intake and exhaust ports. the reason I needed longer valves is because the installed spring height was at 1.800 and I needed 1.900 for my springs. I have a mechanical roller with 6.500 net lift. The guide plates are stock items, the pushrods came out to be 8.450. the studs were from comp cams, they needed to be shortned .500 to all the lock nut to work correctly.These heads have a 60cc closed chamber. the ports have been reshaped, but still in the stock location.I put these on a 383 stroker block with 18cc dish pistons, 9.85cr. The piston to valve clearence was .185 on the intake and more on the exhaust. I started the engine on a stand today, will be at the dyno on the 31st or march.