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Head and base gaskets , yes or no ?
Posted:
Sun Feb 26, 2017 3:53 pmby drivera
Trying to set the squish on a 225 Rapido barrel on a Spanish crankcase and can't get much lower than 1.8 using a 0.1 alloy base and a 0.3 head gasket , so could I scrap the base gasket and head gasket and use silicone ?
Re: Head and base gaskets , yes or no ?
Posted:
Sun Feb 26, 2017 4:13 pmby Adam_Winstone
Personally, I'd choose to lose the head gasket first but you need to make sure that the head and top of barrel faces are both flat, then use silicon on the head and be happy with the 1.5mm squish. You can lose the base gasket too if you feel so inclined, using silicon there too, however, I personally like 1.5mm as my target anyway... perhaps not 'optimum' to some but I'd rather know that I had a little room for error as squish can vary as a result of machining and assembly factors. It is easy to find that a 1.5mm squish closes up to 1.0mm somewhere around the head unless the head is doweled for perfect centralisation.
If you can still access the old Taffspeed Tuning web pages / info then it'll tell you that they preferred to assemble top ends with neither head nor base gaskets, as they are just one more thing to blow/fail.
Adam
Re: Head and base gaskets , yes or no ?
Posted:
Sun Feb 26, 2017 8:53 pmby dscscotty
you'll be fine running without gaskets, flatten cylinder and head off on flat plate and use three bond to seal it. it'll be fine, try get a reasonably low squish to keep temp down.
Good Luck
Re: Head and base gaskets , yes or no ?
Posted:
Sun Feb 26, 2017 9:04 pmby drivera
Ta for replies , think I'll have a go " gasketless " then
Re: Head and base gaskets , yes or no ?
Posted:
Tue Feb 28, 2017 7:18 pmby Simon ELC
I have no gaskets and a 1.1mm squish on my TS1 250. And that's with a 64x115 crank. Runs fine.
Re: Head and base gaskets , yes or no ?
Posted:
Thu Mar 02, 2017 9:03 pmby P D: SC Chester
Was just fitting new gaskets, before I snapped a ring
Can someone explain the disadvantages of having the squish too big?
I had good compression, but couldn't get a reading on my solder, indicating a squish over the required amount. Will try it without the Base gasket, see if I can get it down.
Re: Head and base gaskets , yes or no ?
Posted:
Thu Mar 02, 2017 9:03 pmby P D: SC Chester
Was just fitting new gaskets, before I snapped a ring
Can someone explain the disadvantages of having the squish too big?
I had good compression, but couldn't get a reading on my solder, indicating a squish over the required amount. Will try it without the Base gasket, see if I can get it down.
Re: Head and base gaskets , yes or no ?
Posted:
Thu Mar 02, 2017 11:00 pmby holty
with too big a squish you will have a reduction in performance, ideal squish should be between 1.2 and 1.5mm having the correct squish will also make the engine run cooler, setting the correct squish can transform an engine, especialy a tuned one, well worth doing in my opinion.