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Bringing American ingenuity... | |
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...To an Italian Masterpiece |
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The 308 engine comes equipped
with hollow stem, sodium filled exhaust valves. Not only is
this a weak link, but should the sodium come in contact with
water during a failure, the reaction is extremely violent.
There are very few builders using sodium filled valves today
for this reason. We replace all 308 intake and exhaust valves
with stainless, and have found that there is even room to
increase the head diameter by a millimeter or two. The larger
valve along with some porting seems to show a worthy improvement
in air flow.
Hopefully we will never need to do this extensive of a repair for you. This 82 Mondial was out late one night with its owner when a beautiful blonde flew by in a Viper. The owner thought he could catch her and, well, you can see the result there to the right. J.R. said I could use his story as an example of what not to do, but he asked me to be gentle, "she was really pretty".
Notice in the close up of the destroyed chamber, you can see the hollow stem of the exhaust valve where the head of it broke off. |
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Here's a 308 head being flow tested after receiving the larger valves and some extensive flow work. Every Ferrari head is meticulously tested before leaving the shop. |
3.5 and 4.0 Litre conversions
for your 308!!
For the last couple of years we've been involved
in a massive research and development project with
the 308 cylinder head. We've changed valve head
diameters, valve stem and valve guide diameters,
valve face and seat angles, seat depths, valve lengths,
port volumes, chamber sizes, and cam profiles while
working with Nick's Forza Ferrari on their conception
and development of the "358" and "408"
Ferrari engine. Nick's Forza Ferrari is in the final
stages of development of the 4.0 litre 308 as well
as a more affordable 3.5 litre version.
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The torque of a 360 from your
308!!
To the left is the prototype 3.5 litre on the
engine dynamometer. In the photo directly above
it's tucked nicely into it's home. Below is the
car on display as you may have seen it at this year's
Concorso Italiano in California. In it's current
state the engine is out pulling a 355. With tuning
we expect to exceed that of the 360.
For more information on 3.5L
and 4.0L conversions,
click here:
http://www.nicksforzaferrari.com
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355 / 360 HEAD REPAIR
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The
355 is a 3.5 litre engine with a 5 valve per cylinder,
dual over head cam cylinder head. It really is a very
impressive design with one exception; in the early models,
Ferrari used the same soft copper alloy valve guides
that they used in the earlier 2 and 4 valve 308 and
328 heads, and they have a very short life expectancy.
We replace these with a much higher quality manganese-bronze
guide that will take whatever you can give it (see photo
below). We also replace the stock valves with custom
high performance stainless valves.
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Valve Guides
In the photo
on the left, the copper colored valve guide on the far
left is the original guide used in the early 355s and is made
of a copper alloy material. This is a soft material that causes
the guide to wear quickly and fail prematurely. The guide
in the center is made of iron and came standard in the head
that Ferrari used in the later 355s and 360s and also when
they had to replace heads with failed copper alloy guides.
The iron guides seem to hold up well and rarely need replacing.
Notice, however, how it is straight with no flange. This could
allow the guide to "walk" down into the heads and cause severe
damage, especially if an engine were to overheat. On the far
right is the manganese- bronze guide we use to replace the
original flanged guide.
In the photo on the right are the guides we custom
build to replace the non-flanged iron guides when necessary.
Notice the small round "bump" we leave to insure the guide
can not walk down into the head.
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a 355 head with the new valve guides. The seats are finished
with a 3-angle valve-job where there was only a single
angle seat in stock form. We also hand-polish the chambers
to a high luster as a final touch. It's this attention
to detail that sets us apart from the competition.
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On
the right, this head is finished and getting ready for
final assembly. To the left you can see our custom stainless
valves available at a very reasonable price.
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Just for
fun
It's not everyday one gets a look at a 355 / 360 Ferrari camshaft,
so here's a good shot of it. This cam design is an engineering
marval. Look closely at the lobes; the center lobe looks normal,
but the outer two lobes are conically ground to match the
compound angle of the valves.
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Replace your brittle sodium filled valves with durable stainless. Almost any valve custom made for around $40.00 each
Performance cylinder head
rebuilding for import & domestic heads. High performance head porting,
polishing, rebuilding