TOPIC:

I did a compression test on my 1000 today, 125,115,120 and 95. Service manual calls for 159-188 PSI. I removed the top end, what would you guys reccomend, go 1st over with OEM parts, or install a big bore kit, nothing crazy, 1075 or something close to it. Thanks for the input !!

That is an easy question that only you can answer .Are you saticfied with the current power? Yes? Go 1 over.No,go bigger.If you want more power go as big as you can in that bore .You can get stock jugs cheep,so if you ever need a rebore you could buy new jugs and rings and reuse the pistons.Or at that time you could resleave and go bigger.

Champ440 wrote:

install a big bore kit, nothing crazy, 1075 or something close to it. Thanks for the input !!

FYI, This guy has the 1075 kits for the "J" motors for the same price. tinyurl.com/v3r7s

Champ440, Please describe the procedure you used to check the compression. Also, there is no way to know why the compression is low. I suggest you FIRST adjust valve clearances then recheck. Hold the throttle open this time otherwise the numbers will be low. Last, if yo find that the valve clearances are not the cause of your low compression or the way you did the testing, then you will have to remove your block and pistons and measure the diameter of both to determine if they are within spec. The clearance, if it is in spec, will allow you to just rering after honing the cylinders and this costs a lot less than big bore kits and boring the cylinders.

wiredgeorge wrote:

I suggest you FIRST adjust valve clearances then recheck. Hold the throttle open this time otherwise the numbers will be low.

Looks like it is a little late for that WG. In his post he states "I did a compression test on my 1000 today, 125,115,120 and 95. Service manual calls for 159-188 PSI. I removed the top end, what would you guys reccomend"

I would go with the 1075 kit and be done with it. If you don't you will always wonder what if...

Done ! Guess I will order the K1076 kit, 10.25:1 compression ratio. Thanks for the input from everyone, I just wanted to make sure there were no horror stories about the big bore kits

I read it... I wondered how he measured compression. If he needs to adjust his valves, all the 1075 kits in the world won't bring the compression up.

Being a mechanicial engineer who has raced snowmobiles his entire life, and now owns his own shop doing performance work on snowmobiles, and building marine engines, and marine diesels, to answer your question, yes I know how to do a compression test. The main reason for my post was to see if I recieved positive or negitive feedback reguarding the 1075 kits.
The previous owner of the 1000 ran it for 7K miles with no air filter installed, piston to cylinder clearance 0.098" and the cylinder with 95 psi, had the rings stuck

Wow, Wired, guess you got told -- it was so obvious in the first post. I myself couldn't tell at first if this was a master fabricator or some squid, now the answer is quite obvious.

Much pardons, sir, sometimes we get newbies on here. Rare, and we do try to run the buggers off, no place for a beginner to post. Still it sometimes happens.

gpzrox... I do believe that if you honestly try and help someone, you will get dumped on now and again. I am thinking about taking a break for awhile.

I guess in my first post I should have given a little more back round information on the project and myself. I have been a member of a Porsche forum for years and find the people and the information they provide to be a great asset. I am sure this forum will also provide me with years of information. Sorry if I walked on anyones toes, I just wanted to fill in the missing info.