Reinforced inlet valves HONDA Legend V6 3.5 J35A8

HONDA engines covered

Under the bonnet of the four-wheel-drive Legend IV, from 2006 to 2012, Honda fits the J35A8: a 3.5-litre V6 from the J family, with 24 valves and VTEC variable valve timing.

Its two cylinder heads carry 12 inlet valves, original part number 14711-RJA-000. Sharper camshafts, a higher rev limit or an added supercharger work them far beyond their intended use.

SUPERTECH reinforced inlet valves

The inlet valve admits the charge on every cycle, strikes its seat again and slides constantly in its guide, at 400 to 550 °C. At these temperatures an ordinary chrome-silicon steel drops from 500 MPa at 500 °C to 250 MPa at 600 °C, 50 % less strength.

The HIVN-3536 is black nitride treated, which hardens the stem surface and slows wear in the guide. Its 36 mm dished head is offered in a single size for this engine.

Inlet valve technical specification

HIVN-3536: dished head.

Fitting details

The 5.5 mm KPR-5.5-7A-ST collets are used on the J35A8; they are sold in sets of 16, enough for 8 valves.

The 12 valves are fitted on checked and lapped seats, replacing the valve stem seals at the same time.

Technical guide

The brand offered

A Californian workshop focused on racing for more than thirty years, SUPERTECH Performance designs valves, springs, retainers and guides, each batch being checked by ultrasound, X-ray and laser.

How to choose

The groove is the recess machined at the end of the stem where the collets hold the upper retainer. For the J35A8 a single version is offered:

When reinforced valves become necessary

• Sharper camshafts or stiffer springs
• Higher rev limit
• Added supercharger or turbo
• Cylinder heads rebuilt for track or hillclimb
• Worn original valves or seats already reground

Compatible vehicles

OEM part number (inlet valve): 14711-RJA-000

Related products

With both cylinder heads off, replace the 12 exhaust valves of the J35A8 as well.