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94 cylinders
Posted: Tue Sep 10, 2002 6:35 am
by vicsvw
Yes the Heads & Case must be cut and the stock 8mm case savers must be used. Remember to keep the compression low. Vic >>
http://www.1800vw.bizhosting.com/cutcase92s.htm << If you don't keep the heat down you will end up with less HP then with 92's
94 cylinders
Posted: Tue Sep 10, 2002 6:40 am
by Marc
I'm assuming that the case and heads have both been opened up for the larger cylinders already.
The pushrod length needed is affected by the cam base circle, the thickness of the lifters, the installed height of the valves, the rockerstand height, any barrel spacers or headgaskets used, and the type & condition of valve adjusting screw and rocker arm ratio. Normally there would be no need to modify the cylinder, but do check to make sure that it is seated all the way into the head and not contacting the bottom fin - you might need to clearance the head slightly.
94 cylinders
Posted: Tue Sep 10, 2002 6:55 am
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by vicsvw:
[...] Remember to keep the compression low.<HR></BLOCKQUOTE>
I strongly disagree. Lower compression is the last resort of the bad build.
94 cylinders
Posted: Tue Sep 10, 2002 7:57 am
by Marc
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by
[email protected]:
<B> Lower compression is the last resort of the bad build.
</B><HR></BLOCKQUOTE>
Which is why the factory built `em so low. They obviously had no faith in the quality of the original German components and their ability to build an engine right when they dropped the C.R. of the 1600DP from 7.6 to 7.3:1.
By using the superior Brazilian and Chinese parts we have at our disposal today and taking advantage of the "dynamic compression ratio" concept that has apparently just been discovered, it's now safe to build your first engine on the kitchen table at 8.5 or 9:1. It should easily run for 175,000 miles on Regular gas and never have any overheating problems either (No, wait, that's the original 7.3:1 `72 engine in my car right now).
94 cylinders
Posted: Tue Sep 10, 2002 9:06 am
by Bucko
I was always told to keep a "street engine" to no more than 9:5:1 compression, and keep the timing within safe limits. That's with using good 91+ octane fuel as well. Anything above that causes detonation and/or ping.
If your on the track only, that's another story (again, so I've been told).
94 cylinders
Posted: Tue Sep 10, 2002 5:03 pm
by 74baja1915
I have a 1915 with 8.3-1 comp and i have no problems with overheating and the motor runs great. do a search for compression and look at Jake Rabes replies.
------------------
If its not broke don't fix it, but if it can be made better by all means do it!
94 cylinders
Posted: Tue Sep 10, 2002 5:19 pm
by Marc
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by 74baja1915:
<B>I have a 1915 with 8.3-1 comp and i have no problems with overheating and the motor runs great. do a search for compression and look at Jake Rabes replies.
</B><HR></BLOCKQUOTE>
And I run 10.5 to 11.25:1 on race engines. I'm not afraid of high compression, I just know that it has its place, and it's not on a daily driver for the street. 8.25:1 is a good maximum for pump Premium if the rest of the combination is right, so your positive experience is no surprise to me.
Jake knows his stuff, but he's pushing the envelope - the average home-builder who hasn't the facilities to do so would be well-advised to stay closer to Wolfsburg specs than the ones from Cleveland, Georgia.
Check back in 50 or 60 thousand miles, though, OK?
94 cylinders
Posted: Tue Sep 10, 2002 5:28 pm
by 74baja1915
Yes i guess you have a good point Marc.
My motor was built for me and was done up very nice. And its in a baja so keeping it cool is easyer. But i will check back with ya in 50-60 thou miles. but so far it runs great just wearing out transmission mount!!!
(you know all that raw power)
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If its not broke don't fix it, but if it can be made better by all means do it!
94 cylinders
Posted: Tue Sep 10, 2002 6:01 pm
Say 74baja1915, what kind of tranny mounts are you running?
94 cylinders
Posted: Tue Sep 10, 2002 6:07 pm
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Marc:
[...]<HR></BLOCKQUOTE>
You did take your tongue out of your cheek before going on with the rest of your day, right?
Given the poster's actual configuration, you are probably right. It sounds like he's on economy grounds to begin with.
But I'll stand by what I said and qualify it by explaining that by Quality Build I mean not South American parts, or the crap made by the usual suspects and assembled by The Rest of Us.
94 cylinders
Posted: Tue Sep 10, 2002 7:01 pm
by 74baja1915
Well john i bought the car and they were stock mounts that looked good and after 1000miles with the 1915 they wore out pretty bad. I have a post in the offroad forum asking about different types of mounts that i can replace the stock ones with, that will live a long life with the 1915
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If its not broke don't fix it, but if it can be made better by all means do it!
94 cylinders
Posted: Wed Sep 11, 2002 4:40 am
by Marc
...I was under the impression that the head should fit snug to the top of the cylinder... [/B]
The spigoted end of the barrel should be seated firmly against the flat surface of the head that surrounds the combustion chamber, but there's no way for you to see that directly other than fitting a barrel into the head before it's on the engine and liiking up through the inside.
It sounds like the gap you describe is typical; the area that you can see with the barrels and head installed is not supposed to be a sealing surface (if there was contact here, it would be bad since it might inhibit the sealing at the right place).
94 cylinders
Posted: Wed Sep 11, 2002 5:33 pm
by john
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by 74baja1915:
<B>Well john i bought the car and they were stock mounts that looked good and after 1000miles with the 1915 they wore out pretty bad. I have a post in the offroad forum asking about different types of mounts that i can replace the stock ones with, that will live a long life with the 1915
</B><HR></BLOCKQUOTE>