"Bowen, Patrick A" wrote:
>
> I am in the middle of tearing down my engine for a rebuild (it has been
> sitting since 1992 completely open with the head off) In so doing I decided
> to figure my displacement and compression (hence my earlier e-mail) when I
> figured up the displacement I came up with 1684cc is this right or have I
> been sniffing a little bit of exhaust fumes. Is it possible for someone
> before me to have increased the displacement that much? I used brake fluid
> to measure the displacement (it was available OK) measured by using 60cc
> irrigation syringes (benefits of working in a hospital) 100% accurate,
> probably not, but I don't see how I could be off by 200cc. I was under the
> impression that the engine had never been touched, with an actual 56K miles
> on the engine (I did discover an odd screw on the oil pan, so I know it has
> been off before) How can I tell if the engine has been rebuilt before? and
> How can I tell how much as been removed from the head and engine deck
> surface. The engine has flat pistons that are at 0 deck height at TDC, is
> this normal?
I'd remeasure the engine Bore and stroke and apply the following formula
to arrive at the displacement.
Bore X Bore X .7854 x Stroke X 4 (number of cylinders)
The stock 1500 is: 73.7 (mm) bore X 87.5(mm) stroke and comes out to
1493117.2641 (mm) and rounded off and converted to cc's it is 1493. So
in order to calculate a modified engine, add (or subtract) the
modification to the bore or stroke from the dimensions and recalculate
the displacement. Make sure you are using the same scale. If you bored
it .020, you will have to convert that .020 which is an inch measurement
to mm so the result will be accurate.
The internal parts should tell you if the engine was previously
modified. It is not common that standard parts would be used in a
refurbished engine. And oversized pistons would be marked as such.
Decking the head will not affect displacement, only compression. If it
has been modified a great deal, you should be able to tell by looking at
the surface. Where the pushrods go through will have noticeable areas
where you can tell.
>
> The crank appears in outstanding condition, no scoring, thrust bearings were
> good with almost no runnout. The cam looked ok, but it did have dark spots
> (half moon shaped on the edges) is this scoring? and do I need to replace
> it. If I am taking the engine to be hot tanked do I need to clean it at all
> or let the machine shop deal with it? And what is the list of "must do's"
> since I am having the block machined. what else should I have done.
Take both the cam and crank to a machine shop and have them test both
parts for cracks and wear. Micro cracks are invisible to the naked eye
and will render the parts useless. These tests are not extremely
expensive and are well worth the investment in piece of mind.
>
> How bad is it to reuse old valve springs, the machine shop said they were
> fine, but they didn't test or measure them.
Valve springs are pretty reliable, but can break and if they do, the
results can ruin your whole day. Check the prices of new ones and make
a decision as to whether the added expense is warranted. Of course even
new ones have been known to break, but it is probably less likely.
>
Good Luck,
Joe
--
"If you can't excel with talent, triumph with effort."
-- Dave Weinbaum in National Enquirer
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