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Discussion Starter · #1 ·
You know, Stage I, II, III (or Stage 1, 2, 3 for search purposes).

i.e. what would all Stage 1 head work consist of?

What additional work would Stage 2 heads be treated to?

Stage 3? etc.

Did any V6 heads get prepared beyond Stage 2? I have seen 4-cylinder powered cars with supposed "Stage 4" or "Stage 5" head work - but have only seen a V6 powered car with "Stage 2" work done.

Did Sperry offer the same number of available preparation levels for both engines??

Other than a European Car GTV6 article which lists what goes into the Stage 2 preparation, I can't find anything concrete for the V6 cars.

Anyone have an old Sperry catalog - or firsthand knowledge - of what qualified/quantified the different ratings?
 

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Stage 1, was full radius cut seats and improved valve guides. Basically just a really well done valve job with full radius cut seats.

Stage two was same as above but with porting work.

Stage three was Stage 2 with the addition of the bigger intake valves.

Stage four was Stage three with bigger exhaust valves.

Greg,
Silicone Hose Kits
OKINJECTORS.COM

P.S. The Sperry Valve works video is a VERY good instructional video about valve jobs on our engines.
 

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Rob, if you are just looking for info on V6 head prep you may want to take a gander at this article by Scott Potter.
 

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Discussion Starter · #6 ·
Rob, if you are just looking for info on V6 head prep you may want to take a gander at this article by Scott Potter.
Thanks for the link. Great info.

I won't be doing any work like this soon, but I was curious about the Sperry work (specifically) as I see cars advertised with their work occasionally.

I also thought it might be useful for anyone else who searches the forum to have it readily available here in a specific thread (with opinions of work from Sperry aside), rather than buried in a completely different thread regarding modifying the V6 for more performance. That's a completely different can of worms, and judging by the ones that already exist: it can become a pissing match and good info gets tangled up in it!
 

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Discussion Starter · #7 ·
And now, to post the info within the actual BB (material re-posted from Sperry website cache):

Begin Sperry material:

Head Preparation for the V-6
(priced per pair)

Sperry Valve Works offers 4 different Stages (for the V6) of head preparation detailed and priced below. Not included in the head preparation stages below is the removal and replacement of cams, rocker shafts,3 cam seals and the adjustment of valve clearances. These services are explained below. Find out more details by watching our video tape.

Stage I Head Preparation $585.00

Stage I Head Preparation includes: disassembly of valves (not cams or rocker shafts); chemical cleaning; inspection and measuring of parts; vacuum testing of heads; cleaning and grinding of valves; removal and replacement of valve guides with extra life silicon aluminium bronze valve guides. Guides are diamond honed to size. Seats are cut using a new, full radius cut (superior to a multi-angle cut). All valves are hand lapped to ensure a perfect seal. The heads are surfaced with a minimum amount of material removed to ensure flatness. Gasket surfaces are cleaned, all studs are checked and heads are chemically cleaned again to remove machine filings. The heads are assembled using our high performance valve springs and Viton valve guide seals. Our Stage I Head Preparation is superior to the stock Alfa head and the work other machine shops produce because of the improved airflow gained by our full-radius seat cutting technique and our 15 years experience specializing in only Alfa Romeo.
Price Break Down

High Performance Valve Job...............................................$375.00
Silicon Aluminum/Bronze Valve Guides with Viton Seals.............80.00
High Performance Valve Springs...........................................130.00

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Stage II Head Preparation $1045.00

All work performed in the Stage I Head Preparation is included with the addition of porting and polishing the intake and exhaust ports, thus maximizing airflow for increased performance. Most of the porting is done within 1-1/2 inches of the valve seat area on both intake and exhaust sides. In stock form the intake ports in the V-6 are very restrictive in these areas. Since the stock valves in the V-6 alreay have a 45° seat angle, the Stage II Head Preparation rates as the most cost effective head preparation stage. The techniques used during porting and polishing in our Stage II Head Preparation werre developed from countless hours spent on our flow bench over the last 15 years. We are constantly developing new and innovative ways of getting the most performance for our customers.
Price Break Down

High Performance Valve Job..............................................$375.00
Silicon Aluminum/Bronze Valve Guides with Viton Seals............80.00
High Performance Valve Springs..........................................130.00
Port and Polish Heads........................................................400.00
Set Valve Spring Heights......................................................60.00


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Stage III Head Preparation $1,420.00

In addition to all of the work performed in both stages 1 and 2, we add 6 oversized intake valves and seats. The head diameters of these oversized valves are 1.650" in the 2.5 liter engine and 1.775" in the 3.0 liter engine. The valve contact angle is 45° and only our valve shape provides the most airflow improvement over the stock intake valve. Only by installing our special alloy oversized intake valve seats is it to achieve the complete big valve advantage without risk of seat failure. No other shop intalls oversized valves with our special alloy seat. Most shops don't install oversized seats at all. This is an important question to ask when comparing work and prices.
Price Break Down

High Performance Valve Job..............................................$375.00
Silicon Aluminum/Bronze Valve Guides with Viton Seals............80.00
High Performance Valve Springs..........................................130.00
Port and Polish Heads........................................................450.00
Remove Seat Pockets & Install 6 Oversized Seats...................85.00
6 Oversized Intake Valves..................................................150.00
6 Oversized Intake Valve Seats.............................................90.00
Set Spring Heights...............................................................60.00


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Stage IV Head Preparation $1,795.00

Stage IV Head Preparation is identical to Stage III Head Preparation except for the addition of 6 oversized exhaust valves and seats. The head diameter of these oversized exhaust valves is 1.457". Also, more material is removed during the porting process to further improve airflow on the exhaust side. It is also possible to install valves on the 2.5 liter engine as long as the special 3.0 pistons & liners are installed. This modification requires special machining of the block to accept the 3.0 liners which turns your 2.5 liter engine into a 2.8 liter! Stage 4 is not available for the 3.0 liter engines.
Price Break Down

High Performance Valve Job..............................................$375.00
Silicon Aluminum/Bronze Valve Guides with Viton Seats............80.00
High Performance Valve Springs..........................................130.00
Port and Polish Heads and Intake Runners...........................500.00
Remove Seat Pockets & Install 12 Oversized Seats................170.00
12 Oversized Intake Valves................................................300.00
12 Oversized Intake Valve Seats.........................................180.00
Set Spring Heights...............................................................60.00


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Remove & Reinstall Cams, Rocker Shafts, 3 Cams Seals $236.00 and Adjust Valve Clearances

In order to perform the above Stages of head preparation the camshafts, rocker shafts, idler pulley and cam seals must be removed for proper cleaning and reinstalled (special tools are required). Sperry Valve Works offers the removal and reinstallation of these items plus adjustment of valve clearances as an additional service. Cost of labor is $200.00. Cost of 3 cams seals and 2 O-rings is 36.00.
 
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