Tired of loosing your time honing and fitting valve guides?
REAMING ADVANTAGES OF USING AV&V™ CARBINE REAMERS.
Here is why AV&V™ reamers are now used by the top cylinder head shops in the industry.
Tips for valve guide removal and installation
At JPrecision’s / AV&V™ Performance and Testing Lab, we have removed and installed hundreds of guides every year with no comeback and without damaging the heads, by proceeding as follows:
For Pan®, Shovel®, Ironhead® and early, soft cast iron EVO® guides, we use a piloted counterbore tool on the press drill. We install the head on a fixture and cut down the top portion of the guide flush with the spring seat surface.
Next, the heads are put into the oven at 140°C (300°F) for half an hour, after which we place them on two 2” x 4” wooden blocks and drive out the guides with a hammer & driver. The guide exits on the chamber side.
For late EVO® and early Twin Cam® with 5/16 or hardened cast iron guides, we first spray WD-40 penetrating oil on the guide tops and then use a hydraulic press to press the guides out through the combustion chamber.
For late Twin Cam® with 7mm guides, we first spray WD-40 penetrating oil on the guide tops and then remove the circlip. Then we use the hydraulic press to press the guides out through the combustion chamber.
For installation, we use the shrink-fit method. Before the heads go into the oven, we chamfer the guide receiver holes with a hand deburring tool. We blow out the chips and visually inspect the holes. Next, the heads are put into the oven at 140°C (300°F) for half an hour.
We apply pressfit lubricant on the new guides and put them in dry ice (a freezer can also be used). After a few minutes, the first head comes out of the oven and is placed on two 2” x 4” wooden blocks. We then retrieve the first guide from the dry ice and install it as quickly as possible with a hammer and driver.
If you follow the correct process, the guide should enter the head half way before you need to hammer on the driver, and no superhuman hammering effort will be required. If this occurs, it is due to choosing an oversize that is too large.
Repeat the same process with the other guides.
REAMING ADVANTAGES OF USING AV&V™ CARBIDE REAMERS
There are two ways of fitting a valve guide: reaming and honing.
In the past, good engine builders had no choice but to hone the guides to fit them to the correct specifications. Reamers were available, but their piloted section was too short and small for proper alignment when reaming. In addition, high-speed steel reamers were not designed to ream special bronze alloy valve guides.
When using the Sunnen method, you must choose your mandrel and stones and use coolant. Remember to hone, measure, and re-hone until the correct fit is achieved. Take care not to hone your guides with a taper in the centre, and remember to wash the heads and your hands to complete this operation. The entire process usually takes 20-30 minutes.
With the AV&V™ carbide reamers (photos on our website), it only takes 3-4 seconds to fit a guide to exact tolerances with no taper, and there is no need to wash anything before going on the seat machine.
AV&V™ valve stem diameters are designed to require the same AV&V™ reamer to fit both the intake and exhaust valve:
- AV&V™ VGRC3120 reamer will fit all of our EVO®/Twin Cam® valves
- VGRC3782 fits all of our Pan®/Shovel® valves
- VGRC2766 fits all AV&V™ and other Harley 7MM valve brands
As no crosshatch is left in the valve guide I.D., the tight clearance achieved will lead to longer valve and guide life.
The seat job may now be started. As these reamers are made from solid carbide, they will last much longer than any high-speed reamer.
The same three reamers have been in use in our tech lab for years. We still appreciate them with every use, even after reaming thousands of guides. The world’s top cylinder head companies and shops now use AV&V™ valves, valve guides and reamer system to improve production time and the quality of their work.
We take great pride in the fact that over the last decade, the most respected cylinder head specialists in the industry have switched to AV&V™ products in order to deliver final products at the highest possible standard. This select customer group includes T-Man Performance, S&S, ULTIMA, Revolution Performance, Branch & O’Keefe, and many other dedicated cylinder head shops.