BLOCK PROTECTOR PLATES
In recent years a number of aluminum block engines have been produced with the "open block" design. This means that the cylinders are not supported at the top of the block, but simply stick up from inside the bottom of the crankcase. A few examples of this type are Honda, Acura, some Nissan, and some Subaru. This design is OK for normal driving, but at high RPM the cylinders start to move back and forth at the top, and this will eventually result in the complete destruction of the engine.
The answer to the problem is a block protector plate at the top to provide the cylinders with the support that they need. In order to provide this needed support, the protector plate must be WELDED into place. Some firms are supplying plates that are simply tapped into place with an interference fit, and this actually does more harm than good. What happens is that the interference fit squeezes the cylinders at the top and actually decreases the cylinder bore by a few thousandths of an inch. When the engine is revved up and really gets hot, the pistons try to seize up at the top where the bore is too small and the engine comes apart.
Our plates are designed to be welded in place and we can provide this service for you. If you have TIG welding and milling equipment then you can do it yourself. Most people do not have the equipment or the skill to do this themselves. If you do, that's fine -- we'll sell you the plate and wish you luck. If you don't, you can send your block to us and we will do the job for you. Most of these blocks are light enough to ship by UPS. The installation procedure is as follows:
1. Clean the block (Welding sets grease on fire)
2. Fit the plate in place (hand filing & grinding)
3. Weld the plate (TIG welding only)
4. Mill the block true (Smooths the weldment flat)
5. Bore and hone the cylinders (Optional)
After the plate is properly installed, the cylinders will absolutely not move anymore. This means that they can accept the pressure of high compression ratios, high turbo boost, or large nitrous shots. You may still need to address the issues of pistons, rods, etc., as the weak points in the engine, but the cylinders are taken care of.
TO ORDER OR FOR MORE INFO CALL (205) 823-7278
SHIPPING YOUR BLOCK:
It is not necessary to build a completely enclosed crate to ship the block. A piece of 1/2" thick plywood bolted to the bottom and another piece bolted down on top should do the job. The plywood should overhand all four edges by an inch or so. UPS will accept shipments up to 150 pounds, and most 4-cyl aluminum blocks are well under this. We will return the block to you the same way.