Head Service

Performance mod / head service

SFR cylinder head ''mod'' consists of multi-radius cut valve seats and valve lapping. We also lighten your standard OEM valves as well as porting your intake & exhaust ports. There's no need to spend money on expensive after market valves that will not perform any better than lightened OEM valves. Our basic port job consists of widening all choke points, contoured all short radius & blending valve seats to bowls. We also sand and smoothen out all the rough texture in the cylinder head chamber to cut down on detonation. All cylinder head surfaces will be inspected for warpage and then decked to achieve a perfect flat surface with a finish of 30- 40 RA.

Our SFR head ''mod'' will dramatically wake up and improve your crafts performance. The gains are awesome acceleration, more rpm's and top speeds. There are some crazy fully ported cylinders heads out there that won't do much more for your performance other than look trick and take money from your wallet. Please call with any questions you may have regarding our head “mods” 917 559-5744

Cylinder Head Porting $600.00
OEM valve lighting (only 07 & later)
Intake ~44 grams Exhaust ~37 grams
$145.00
Valve seat radius cutting / lapping $245.00
Chamber smoothing $180.00
Decking cylinder head $60.00
Valve re-facing $65.00

 

SMOOTHING OUT CHAMBER

This is how we start to smoothen out the chamber in your cylinder head. This mod will help your 4-tec supercharged engine with detonation.

 

FIRST CUT ON VALVE SEATS

This is an example of how a valve seat looks when we take the first light cut. You can see where our valve seat cutting tool only touched the top and bottom of the seat. This means the valve seat is distorted and the valves were not seating properly ''thus losing power''

 

VALVE LAPPING AND SEATING

The 4 gray strips are where all 4 valves have been lapped and seated creating a perfect seal.

 

COMPLETED HEAD JOB

Head finished with lightened OEM valves

 

MULTI RADIUS 3 ANGLE CUT

The different shads of color on the valve seats indacate the 3 different angles that have been cut into the seat.

 

LIGHT WEIGHT CAM MOD


BEFORE

AFTER
We can lighten your OEM camshaft approximately 215 grams. This mod will remove rotating weight off your valve train thus creating better acceleration. This mod works great with our lightened OEM valves.
Price: $125

 

Through our findings, we have found that just about every 4 tec cylinder head we have checked was always slightly warped or in need of a new valve job. Due to the heat your supercharged 4 tec engine generates the cylinder head and valve seats tend to slightly distort from their original form thus losing compression and power. If valve seats are not re-cut & sealed properly they will allow exhaust gases to push past the valves and contaminate the fresh air charge coming through your ports into your combustion chamber. Valves that are not sealed properly will make tunning your craft very difficult and you may have a hard time obtaining the correct AIR/FUEL mixture. We have also seen cylinder heads in need of valve jobs due to salt water and fresh water ingestion. Water ingestion can cause severe rust and corrosion that will not let your valves seat properly.

Most people may be in denial about there cylinder head being warped or valves not being seated properly. A good automotive leak down tester can be used to check for valve leakage. You may also pull off your plastic intake manifold to see if your intake valves and intake ports show any signs of carbon or corrosion build up.

Our complete SFR cylinder head mod has been tested & proven on our own supercharged 87mph RXP and our customer Steven Reid's 86+mph RXP.

You can simply send us your cylinder head for the services listed above or bring your watercraft to our shop for our services.