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Standard series 3 TV175 squish......

Posted: Wed Aug 29, 2018 6:38 pm
by fluff34567
Hi all,

I have the same Q on FB but maybe targeting a different audience here.

I looked in stickys but didn't see anything.

Anyone know the standard squish on a TV175?

I had the case machined to remove some damage on the base gasket face and supposedly 1mm was removed.

If I use a 1.5 base packer or a 1mm packer and standard gasket plus standard head gasket I get a squish of +-2.2mm. if I just use the standard base gasket and head gasket it's +- 1.2mm... but then the port timing would be out.

2.2mm seems large -. Was the tv175 different to the others?

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Re: Standard series 3 TV175 squish......

Posted: Wed Aug 29, 2018 9:52 pm
by holty
i would aim for 1.2 squish, but your port timing needs to be correct as well, 2.2 is massive and would cause power loss for sure.

Re: Standard series 3 TV175 squish......

Posted: Wed Aug 29, 2018 10:34 pm
by rosscla
1.2 is the target though I suspect this matters less in standard engines than in tuned ones.

How thick are your head and base gaskets?

How much below the top gasket face is the piston at TDC?

The only way you'll improve what you have, without engineering is to leave the gaskets out.

You could skim the top or bottom of your barrel depending on the position of the piston at TDC and BDC but this might slightly alter the port timing so you need to understand the impact of that.

Re: Standard series 3 TV175 squish......

Posted: Thu Aug 30, 2018 10:34 am
by Muppet
how much clearance gives maximum cooling on an off set squished head?

Re: Standard series 3 TV175 squish......

Posted: Thu Aug 30, 2018 3:07 pm
by johnny650
Muppet wrote:
Thu Aug 30, 2018 10:34 am
how much clearance gives maximum cooling on an off set squished head?

3x metres ;) :lol:
Its not just squish ...there are so many factors involved in determining engine temperature that I doubt you'd get a meaningful answer to that question .

Re: Standard series 3 TV175 squish......

Posted: Tue Sep 04, 2018 9:41 am
by HxPaul
"but then the port timing would be out"


Have you checked the port timing?

Re: Standard series 3 TV175 squish......

Posted: Sat Sep 08, 2018 3:32 pm
by fluff34567
Closure... Port timing was good and after speaking with few tuners appears head is bit of a known issue. Got it down to 1.7mm after a quick skim

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Re: Standard series 3 TV175 squish......

Posted: Sat Sep 08, 2018 4:59 pm
by holty
what gaskets and packers are you using to get 1.7 , my understanding is 1.2 is the best squish for power and also runs the coolest

Re: Standard series 3 TV175 squish......

Posted: Sun Sep 09, 2018 8:43 am
by fluff34567
1.5 packer but 1.0 has been removed from the casing so it's the same as having a standard gasket on a standard case. Port timing comes into play here if adjusting the base thickness. No head gasket used.

Depends who you speak to, stickys says 1.2 - 1.5 that's from MB I believe, others say max 1.75. all depends who you talk to.



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Re: Standard series 3 TV175 squish......

Posted: Thu Apr 16, 2020 8:43 pm
by YAMLAM
did Innocenti give squish clearences back in the day ?