sway-bars

[thomas g. warner]

Hey Arch! I talked to Joe Mondello from California yesterday about getting a
455 engine from him. Wanted to talk about the specs of the engine. First
question he asked is what version of GMC motorhome engine do you want.
Stumped me! Seem his regular engine with lots of goodies develops 500HP and
goes for $10K. The one for $6200 he quoted me earlier was for a plain jane
stock 455. He says he is selling these 500HP versions as fast as he can make
them. Even just shipped one to Australia.

Here we are talking about patching up distorted exhaust manifolds and there
are GMC's running around with 500HP motors in them. anyone say one yet?

He told me that just adding the new aluminum Edelbrock heads adds 150HP to
the standard engine. Heads cost $1395 a pair.

>Terry
>
>It is so nice to see Someone remember Colin Chapman. He was good!
>A lot of suspension stuff goes back to him. That was my Bible when
>I was building fun toys. I agree this aint no race car. The problem
>is: a whole lot of us want it to be our fantasy race car------the one
>we never had. After all it does have a legendary engine. A big one too.
>The trick is to separate fantasy and reality. Never easy here.
>
>Take Care
>Arch
>>
>> In the late 50's a gentleman by the name of Colin Chapman wrote a book on
>> suspension in racing cars. Facinating reading. But basically speaking the
>> only
>> purpose of a swaybar is to keep the car level through a corner. If you
>> increase the
>> diameter (front) or add one (or two) to the rear it will stop some of the
>> sway.
>> But now you have a situation where if the left wheel drops into a hole the
>> vehicle
>> pitches to the left. If we are blessed with highways and no chuck holes, we
>> would go for the biggest bars we could find. Or if used off road, we would
>> use the
>> smallest diameter sway bar or none at all.
>> The purpose for having one in the front and not in the rear is to create a
>> situation called
>> roll-steer.The engineers designed this into the GMC to keep the effort at
>> the steering
>> wheel the same through a variety of corners and speeds, all of which is a
>> compromise.
>> The bottom line is this an't no race car. Slow down and enjoy the scenery.
>>
>> Just my two and one-half cents worth
>> Terry Skinner
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach

 

[thomas g. warner]

Forgot something Arch. Some years ago a friend of mine bought a Lotus super
7 that Colin Chapman had worked over.

>Terry
>
>It is so nice to see Someone remember Colin Chapman. He was good!
>A lot of suspension stuff goes back to him. That was my Bible when
>I was building fun toys. I agree this aint no race car. The problem
>is: a whole lot of us want it to be our fantasy race car------the one
>we never had. After all it does have a legendary engine. A big one too.
>The trick is to separate fantasy and reality. Never easy here.
>
>Take Care
>Arch
>>
>> In the late 50's a gentleman by the name of Colin Chapman wrote a book on
>> suspension in racing cars. Facinating reading. But basically speaking the
>> only
>> purpose of a swaybar is to keep the car level through a corner. If you
>> increase the
>> diameter (front) or add one (or two) to the rear it will stop some of the
>> sway.
>> But now you have a situation where if the left wheel drops into a hole the
>> vehicle
>> pitches to the left. If we are blessed with highways and no chuck holes, we
>> would go for the biggest bars we could find. Or if used off road, we would
>> use the
>> smallest diameter sway bar or none at all.
>> The purpose for having one in the front and not in the rear is to create a
>> situation called
>> roll-steer.The engineers designed this into the GMC to keep the effort at
>> the steering
>> wheel the same through a variety of corners and speeds, all of which is a
>> compromise.
>> The bottom line is this an't no race car. Slow down and enjoy the scenery.
>>
>> Just my two and one-half cents worth
>> Terry Skinner
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach

 

[zachary zehnacker]

Tom,

At what RPM do those heads make that much more horsepower? If he was
talking about 150 HP at a reasonable RPM with the stock intake, then that
is pretty impressive! I find it pretty tough to believe that those heads
could make 150 more horsepower (our 455's are only rated at something like
225 horsepower stock IIRC) on our stock engines with no other improvements.
I pretty sure they have smaller chambers, so they probably raise the
compression some. You can get away with more compression and timing with
the aluminum heads, but 150 HP worth would be pretty surprising to me.
Maybe if you commit to Ultra 94? Even though Aluminum can handle more
timing & compression, you also would want to stay farther from the ultimate
limits with Aluminum heads since they are going to be less forgiving to
detonation that does occur than stock heads. I could see it if they are
talking 6000 RPM or something where the stock J heads have long since run
out of air flow, but at low RPM's (He told me that just adding the new aluminum Edelbrock heads adds 150HP to
>the standard engine. Heads cost $1395 a pair.

 

[thomas g. warner]

Zak I first heard about the Aluminum heads when I purchased a copy of
popular Hotrodding Engine Masters magazine, 1998 annual. I bought it just
for the article. I posted some information earlier on this board.

The 455 block has a mild camshaft, 92 octane pump gas, 10:1 compression, 2
inch dyno headers, Edelbrock Performer manifold, 750CFM carb, 1 inch open
spacer, Edelbrock Aluminum heads. Pretty much a standard engine except for
the heads.

It spec'd at:

RPM TORQUE HP
2500 480 228
3000 488 278
3500 522 348
4000 558 425
4500 529 453
5000 493 469
5500 455 477
6000 385 439

According to the article and the tech specs the aluminum heads can
run a much higher compression ratio due to its higher thermal conductivity.

I am convinced that the way to go is with the standard cast iron heads (but
not the J heads) with HD manley stainless steel valves, bronze valve guides
and welded up exhaust cross overs, and a few other things done to the head.
I don't believe porting helps us that much. We are looking for lots of
torque at low RPM's. That is the way I have decided to go on my 455.

>Tom,
>
> At what RPM do those heads make that much more horsepower? If he was
>talking about 150 HP at a reasonable RPM with the stock intake, then that
>is pretty impressive! I find it pretty tough to believe that those heads
>could make 150 more horsepower (our 455's are only rated at something like
>225 horsepower stock IIRC) on our stock engines with no other improvements.
> I pretty sure they have smaller chambers, so they probably raise the
>compression some. You can get away with more compression and timing with
>the aluminum heads, but 150 HP worth would be pretty surprising to me.
>Maybe if you commit to Ultra 94? Even though Aluminum can handle more
>timing & compression, you also would want to stay farther from the ultimate
>limits with Aluminum heads since they are going to be less forgiving to
>detonation that does occur than stock heads. I could see it if they are
>talking 6000 RPM or something where the stock J heads have long since run
>out of air flow, but at low RPM's (site recommends the Torker (higher RPM rated than Performer) manifold for
>the aluminum heads. As we saw with the convertor he sent out to Marcus,
>Mondello is one of the top Olds guys but not really a true GMC guy, and I'm
>sure he doesn't see to many Toronados with the low profile intakes either.
>If you find out more about the details on these heads, please let us know!
>If they are worth the 150 HP at a reasonable RPM and on regular unleaded,
>we should all be going out to get them. There would be no talk of
>different final drives then!
>
>
>Zak
>
>
>
>

>>He told me that just adding the new aluminum Edelbrock heads adds 150HP to
>>the standard engine. Heads cost $1395 a pair.
>
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach