Big Blocks

Ok,if I ever go big block, do the big blocks
cure the head,base gasket leaks? Are any finned
enough to run cool on the street? I saw an Aries
that looked good.I want to hear from people that
have some experience.

In short - no. If you are having sealing problems with the stock block/head/cases - then something is wrong and a big block won't fix it. Ya have to solve that problem first. Things to solve first

1. What base gasket material ?
2. What base gasket sealer if any ?
3. What head gasket material ?
4. What head gasket sealer if any ?
5. What design of head gasket ?
5. Is block O-ringed ?
6. If so - what is the O-ring material (copper wire, silicone, other ??)
7. What type of cylinder studs ? Any possibility of stretch.
8. Possible overtorqueing of head nuts ?
9. Possible torqueing of head nuts in wrong order (yes this really matters)?
10. Were cases machined correctly ?
11. Were cylinders and block machined correctly ?
12. Was head prepped and machined correctly ?
13. Any scratches or gouges in mateing surfaces that the gasket or sealers can't fill ?
14. Is oil pressure OK ? If ya got 125psi oil pressure at 1500 rpm - ya got a problem

Anyway - these are the questions ya gotta answer - and a big block ain't gonna answer them alone

Zippy
MTC big block (among others) owner

Post edited by: zippy, at: 2007/09/09 12:46

I went through all those procedures years
ago when it was a 1170.With a graphite gasket
I put over 30,000 miles on it.Graphite gaskets
are no longer available.I have had it apart
twice,done all the milling,cleaning, torquing,
etc.If you can put a used gasket in the vise
and squeeze oil out of it,I don't see it as the
perfect gasket material.Today after church,I went
for a 120 mile ride and it did not leak.But the
outside temp was only in the low 70s today.Maybe
I am just too fussy about the old motorcycle,but
I am kinda attached to it I guess.Material things
will have their issues,I will fix it one way or
another.

i'm interested in street running a big block too, why dont they make the cooling fins huge, the bikes got a ton of room around the block to spare.:huh:

i know about the air passages being filled in, i just wouldnt want it to overheat when some sportbike pulls alongside of me.

The molds to make the original cylinder
with the air passages would be very
exspensive to duplicate.I have not seen
any aftermarket cylinders that use anywhere
near that complex of a mold.

We make these blocks to go up to 1500cc, so there is no room for air passages.

The blocks have very good finning and still look like a Kawasaki block


Jay

APE Jay wrote:

We make these blocks to go up to 1500cc, so there is no room for air passages.

The blocks have very good finning and still look like a Kawasaki block

Jay

any way someone could run one on the street without overheating, like 8.7:1 comp and a lotta nitrous for the suprise?





:side:

Post edited by: themachine, at: 2007/09/10 22:37

Probably half of the Kawasakis we do are street compression and run on the street.

Jay

Street ratio, around what CR would you consider "street ratio"?

My engine at 10.5 pings only a little on
93 octane,definetly near the limit for
unleaded premium.Ape Jay-does the extra
rigidity of your big blocks aid the gasket
situation? In high pressure hydraulic systems
gaskets are rarely used,tapered metal to metal
contact is used whenever possible.Captured
viton orings are used in some places.An upgrade
somehow for the old KZ would be nice.

Post edited by: tjettim, at: 2007/09/11 06:18

have you tried running a colder plug?

tjettim wrote:

My engine at 10.5 pings only a little on
93 octane,definetly near the limit for
unleaded premium.Ape Jay-does the extra
rigidity of your big blocks aid the gasket
situation? In high pressure hydraulic systems
gaskets are rarely used,tapered metal to metal
contact is used whenever possible.Captured
viton orings are used in some places.An upgrade
somehow for the old KZ would be nice.<br><br>Post edited by: tjettim, at: 2007/09/11 06:18

Is that 1198 bore size on a stock block??