Tomei Powered SR20DE(T) HEAD STUD BOLTS - Manual (Page 7)

7
INSTALLATION
CAUTION
Depending on the condition of the engine, to guarantee the bolts effective clamping force, it's required to bore the
Cylinder Block with the use of a Dummy Head. This ensures the correct clamping force is obtained with the
screw threads. Any block distortions will be corrected. When the bolts are exchanged, it is highly recommended
to bore the block with a dummy head again, even if this had been done before.
As is with the correct size, you When the head is bolted onto the Boring with a Dummy Head
can confirm the correct clearance. Cylinder. The cylinder will distort, will correct the distortions.
clearances will then change. The It will also confirm the correct
distortion amount will be different perfect clearances.
between the stock head bolts &
that of the Tomei Head Studs.
■ This suits engine models produced from October 1993, till September 1997.
(Engines from September 1997 onwards had made a change to this, so the installation cannot be done on these)
■ The chain guide interferes when the Cylinder head is installed after the Head Stud Bolts are installed.
The cut process shown in the figure below is necessary for the chain guide.
CYLINDER HEAD INSTALLED STATE
DUMMY HEAD BORING
D+0.020
D
D+ 0.040 -0.13
D
(D+0.5)+0.020
(D+0.5)
Piston Movement
Cylinder
+0.040
Excessive
clearance
(Blowby)
-0.010
Clearance is too small
(Scouring)
The cylinder is squarely bored straight
to 0.5mm oversized with a Dummy
Head attached. To remove any
Cylinder Bore distortions.
CHAIN GUIDE
Cut here
Cut from the 2nd ridge from
the top.