How it works.

I cannot promise this will always be the latest information , but when things are slack in the garage Ill post up what I can.

Tuesday, 1 November 2005

Engine part 5. Rotating assembly.

Engine balancing.
I neglected to mention that whilst the block was away at South Cerney I also had the rotating assembly balanced at Bassett Down Balancing. Again this company came to me by recommendation.

The crank, rods, flywheel, flywheel bolts, pistons, balancer and one each of the main and rod bearings all went off to Bassett Down. Here I again felt the pain of not buying bits in the correct manner. The crank turned out to be for a 50oz balance whereas the flywheel and balancer were for 28oz. So to sum up a lot of machining work was done to bring it all to 50oz balance, lots of work unfortunately meant lots of money. I now really wish I had purchased a complete rotating assembly as a kit.

Back to engine assembly.

I turned my attention to completing the rotating assembly. The rods I had purchased were for press fit pins, a money saving tip would have been to buy floating pin rods so that I could have fitted the pistons myself. Instead I paid South Cerney to fit the pistons onto the rods for me.

The rings required gapping so I shelled out for a ring grinder from Summit.

Well worth the money but now surplus to requirements. May go on ebay once the motors up and running!

A good tip here is to get a ring board setup, basically 16 screws in a piece of board number 1 – 8 twice. The top and second rings then go on these once gapped correctly. This way, as each ring is gapped to a particular cylinder, it is easy to keep them organised. However don’t do what I did and get confused as to which cylinder is #1!

Each ring was placed into its cylinder and the gap measured, the KB115 piston’s are Hypereutectic and as such run a higher temperature in the cylinder. This causes the top ring to expand and, if not gapped correctly they will but up against each other causing the top ring land to break.

KB state the top ring gap should be 0.0065” for each 1” of bore so 4.030x0.0065 gave me 0.026” of gap, which looks like this:

With the rings gapped and hung on the board I was ready to start fitting them to the pistons. Again each piston was numbered 1-8 and the associated ring set applied for that piston.

The oil rings went on first, first the lower oil ring then the expander and then the top oil ring, the expander has two small pieces of coloured plastic in the end sections to prevent the ring from overlapping itself, when fitted correctly it should look like this.

Next comes the 2nd rings and then the top rings, each of the top rings was identified by a chamfer to the inner edge of the ring and must be placed on the piston the correct way up, a helpful dot etched into the ring tells you which way up.

With all eight pistons ready to install it was time to go for it and fill the cylinders up. Here again I thought it best to get the best tool for the job so I purchased a 4.030 diameter fixed ring compressor from Real Steel. This tool is sized exactly to the bore and has a reducing inner diameter from top to bottom. As the tool is flat bottomed it fits flush to the deck surface, so as long as you keep the tool pressed down the piston should just slide right in, in theory!

Well the theory was good and actually in practice not much different, the only issue I found was that the slope of the engine on the stand caused the rod to slide on the piston pin to the back face of the piston. This then caused the big end to foul on the crank as the piston was tapped home. Not a problem if you are working as a pair but with only two hands it was not possible to hold the rod away from the crank counterweight at the same time as tapping the piston and holding the compressor against the block.

I solved the problem by lifting the rear of the engine stand up so it was level, the rods no long slid and all was well.

Each piston was loaded and the cap loosely fitted, within a relatively short space of time the last piston was going in.

Saturday, 1 October 2005

Engine Part 4 - Stick with me!

Now I was ready to start building up, with the block off of the stand and stood up on its rear face I readied the cam for installation. After wiping the cam bearings down with brake cleaner and paper towel, use paper as other materials will leave fibres that won’t break down in the oil, I also wiped over the cam bearings and the cam lobes. I installed the timing gear to help with the install and applied a liberal coating of Edelbrocks supplied cam lube.

The cam was then easily lowered into the block and the thrust plate bolted down using the correct short headed bolts and Locktite thread locker.

After the cam the engine went back on the stand and it was time to get the main bearing in. Again much cleaning of the block and new bearings and in they went.

After the bearings the crank was cleaned down and trial fitted to check main bearing clearances. Using Plastigauge I obtained clearance within the range I was looking for.

With clearances confirmed I could lube up the crank and rest it in for the final time, main caps on and the new ARP main bolts torqued down to the required value. This was a bit of a job as each bolt was taken to torque and released 4 times before finally torquing up.

More to follow.....

Thursday, 1 September 2005

Engine Part 3.

Continuing the history. so far we are still in 2005!

The block came back from the machine shop looking like new.

I could start work on getting it clean. Here I set aside a morning and armed with air powered degreaser spray, hot pressure washer and a set of engine cleaning brushes I carried out the dreaded cleaning job. It amazing how much muck there was in there from the machining process.

With the block cleaned it was time to start putting in the bits that had to go back before painting it. These were the core plugs, oil gallery plugs and cam plug, all of which went in easily with a little Permatex black.

Now to paint it, I had decided to use POR15 engine enamel but to be perfectly honest the amount of work involved in using the complete system made me opt for VHT engine enamel in a spray can.

I masked up the decks, front cover area and sump area...

and applied 4 coats of enamel.

I also did the front cover and water pump which all in all required 2 cans, thanks to US Automotive for sending out can No.2 so quickly! The finished results I am very happy with.

Well thats a mamoth entry, thats all for tonight!