What's my compression ratio? (head swap question) - Ford Forums

01-13-2006, 17:01

I have 62cc heads currently and my CR is 9.62:1. If I switch to 64cc heads
what would my CR be then? 58cc? What's the math?

--
Scott W.
'66 HCS Mustang 289
'68 Ranchero 500 302
'69 Mustang Sportsroof 351W
ThunderSnake #57
http://home.comcast.net/~vanguard92/

01-14-2006, 09:01

More information is needed to answer this question.
ex 327 ci engine 62 cc 9.62 cr 64 cc 9.4035 cr 58 cc 10.0882 CR
428 ci engine 62 cc 9.62 cr 64 cc 9.4532 cr 58 cc 9.9742 CR
As you can see the smaller engine has a greater change. In each case the
total volume needed for that CR is found, then adjusted and the CR
recalculated.
I have a calculator on my web page that will do this for you.
http://users.erols.com/srweiss/index.html#jcalc
Stan

66 6F HCS wrote:
>
> I have 62cc heads currently and my CR is 9.62:1. If I switch to 64cc heads
> what would my CR be then? 58cc? What's the math?
>
> --
> Scott W.
> '66 HCS Mustang 289
> '68 Ranchero 500 302
> '69 Mustang Sportsroof 351W
> ThunderSnake #57
> http://home.comcast.net/~vanguard92/

01-14-2006, 10:01

Ah, thanks for the link.

"Stan Weiss" <srweiss@erols.com> wrote in message
news:43C92064.5644D25C@erols.com...
> More information is needed to answer this question.
> ex 327 ci engine 62 cc 9.62 cr 64 cc 9.4035 cr 58 cc 10.0882 CR
> 428 ci engine 62 cc 9.62 cr 64 cc 9.4532 cr 58 cc 9.9742 CR
> As you can see the smaller engine has a greater change. In each case the
> total volume needed for that CR is found, then adjusted and the CR
> recalculated.
> I have a calculator on my web page that will do this for you.
> http://users.erols.com/srweiss/index.html#jcalc
> Stan
>
> 66 6F HCS wrote:
>>
>> I have 62cc heads currently and my CR is 9.62:1. If I switch to 64cc
>> heads
>> what would my CR be then? 58cc? What's the math?
>>
>> --
>> Scott W.
>> '66 HCS Mustang 289
>> '68 Ranchero 500 302
>> '69 Mustang Sportsroof 351W
>> ThunderSnake #57
>> http://home.comcast.net/~vanguard92/

01-14-2006, 11:01

You are welcome. If you have any problem running your numbers let me
know and I will run them for you.
Stan

66 6F HCS wrote:
>
> Ah, thanks for the link.
>
> "Stan Weiss" <srweiss@erols.com> wrote in message
> news:43C92064.5644D25C@erols.com...
> > More information is needed to answer this question.
> > ex 327 ci engine 62 cc 9.62 cr 64 cc 9.4035 cr 58 cc 10.0882 CR
> > 428 ci engine 62 cc 9.62 cr 64 cc 9.4532 cr 58 cc 9.9742 CR
> > As you can see the smaller engine has a greater change. In each case the
> > total volume needed for that CR is found, then adjusted and the CR
> > recalculated.
> > I have a calculator on my web page that will do this for you.
> > http://users.erols.com/srweiss/index.html#jcalc
> > Stan
> >
> > 66 6F HCS wrote:
> >>
> >> I have 62cc heads currently and my CR is 9.62:1. If I switch to 64cc
> >> heads
> >> what would my CR be then? 58cc? What's the math?
> >>
> >> --
> >> Scott W.
> >> '66 HCS Mustang 289
> >> '68 Ranchero 500 302
> >> '69 Mustang Sportsroof 351W
> >> ThunderSnake #57
> >> http://home.comcast.net/~vanguard92/

01-14-2006, 15:01

Stan Weiss wrote:
> More information is needed to answer this question.
> ex 327 ci engine 62 cc 9.62 cr 64 cc 9.4035 cr 58 cc 10.0882 CR
> 428 ci engine 62 cc 9.62 cr 64 cc 9.4532 cr 58 cc 9.9742 CR
> As you can see the smaller engine has a greater change. In each case the
> total volume needed for that CR is found, then adjusted and the CR
> recalculated.
> I have a calculator on my web page that will do this for you.
> http://users.erols.com/srweiss/index.html#jcalc
> Stan

I saw your shop's page was on our page, but I'll add this link somewhere
else.

>
> 66 6F HCS wrote:
>
>>I have 62cc heads currently and my CR is 9.62:1. If I switch to 64cc heads
>>what would my CR be then? 58cc? What's the math?
>>
>>--
>>Scott W.
>>'66 HCS Mustang 289
>>'68 Ranchero 500 302
>>'69 Mustang Sportsroof 351W
>>ThunderSnake #57
>>http://home.comcast.net/~vanguard92/
>

--
Wound Up
ThunderSnake #65

AHPBBFM pages: http://tinyurl.com/9yulk

01-14-2006, 19:01

"Stan Weiss" <srweiss@erols.com> wrote in message
news:43C94A87.1F6C54E5@erols.com...
> You are welcome. If you have any problem running your numbers let me
> know and I will run them for you.
> Stan

I've got a .060" overbore with 12cc dish pistons. Everything else is stock.
I don't remember what my engine builder told me on how far down the hole the
pistons are, .04"? sound right? I don't remember. But I do know for a fact
that it worked out to 9.62:1 CR on a 62 cc combustion chamber. 4.060" bore,
3.85" stroke, stock 351 Windsor rod, 12cc dish 302 pistons.
--
Scott W.
'66 HCS Mustang 289
'68 Ranchero 500 302
'69 Mustang Sportsroof 351W
ThunderSnake #57
http://home.comcast.net/~vanguard92/

01-14-2006, 21:01

4.060 bore 3.85 stroke 398.24 ci
62 cc 9.62 cr
64 cc 9.44 cr
58 cc 10.00 cr
Stan

66 6F HCS wrote:
>
> "Stan Weiss" <srweiss@erols.com> wrote in message
> news:43C94A87.1F6C54E5@erols.com...
> > You are welcome. If you have any problem running your numbers let me
> > know and I will run them for you.
> > Stan
>
> I've got a .060" overbore with 12cc dish pistons. Everything else is stock.
> I don't remember what my engine builder told me on how far down the hole the
> pistons are, .04"? sound right? I don't remember. But I do know for a fact
> that it worked out to 9.62:1 CR on a 62 cc combustion chamber. 4.060" bore,
> 3.85" stroke, stock 351 Windsor rod, 12cc dish 302 pistons.
> --
> Scott W.
> '66 HCS Mustang 289
> '68 Ranchero 500 302
> '69 Mustang Sportsroof 351W
> ThunderSnake #57
> http://home.comcast.net/~vanguard92/

01-14-2006, 21:01

Thanks,
Stan

Wound Up wrote:
>
> Stan Weiss wrote:
> > More information is needed to answer this question.
> > ex 327 ci engine 62 cc 9.62 cr 64 cc 9.4035 cr 58 cc 10.0882 CR
> > 428 ci engine 62 cc 9.62 cr 64 cc 9.4532 cr 58 cc 9.9742 CR
> > As you can see the smaller engine has a greater change. In each case the
> > total volume needed for that CR is found, then adjusted and the CR
> > recalculated.
> > I have a calculator on my web page that will do this for you.
> > http://users.erols.com/srweiss/index.html#jcalc
> > Stan
>
> I saw your shop's page was on our page, but I'll add this link somewhere
> else.
>
> >
> > 66 6F HCS wrote:
> >
> >>I have 62cc heads currently and my CR is 9.62:1. If I switch to 64cc heads
> >>what would my CR be then? 58cc? What's the math?
> >>
> >>--
> >>Scott W.
> >>'66 HCS Mustang 289
> >>'68 Ranchero 500 302
> >>'69 Mustang Sportsroof 351W
> >>ThunderSnake #57
> >>http://home.comcast.net/~vanguard92/
> >
>
> --
> Wound Up
> ThunderSnake #65
>
> AHPBBFM pages: http://tinyurl.com/9yulk

01-15-2006, 21:01

I have a page on may web site which lists Automotive newsgroups. If you
give me a one or two line description I will add it need to this group.
http://users.erols.com/srweiss/news.htm
Stan

Wound Up wrote:
>
> Stan Weiss wrote:
> > More information is needed to answer this question.
> > ex 327 ci engine 62 cc 9.62 cr 64 cc 9.4035 cr 58 cc 10.0882 CR
> > 428 ci engine 62 cc 9.62 cr 64 cc 9.4532 cr 58 cc 9.9742 CR
> > As you can see the smaller engine has a greater change. In each case the
> > total volume needed for that CR is found, then adjusted and the CR
> > recalculated.
> > I have a calculator on my web page that will do this for you.
> > http://users.erols.com/srweiss/index.html#jcalc
> > Stan
>
> I saw your shop's page was on our page, but I'll add this link somewhere
> else.
>
> >
> > 66 6F HCS wrote:
> >
> >>I have 62cc heads currently and my CR is 9.62:1. If I switch to 64cc heads
> >>what would my CR be then? 58cc? What's the math?
> >>
> >>--
> >>Scott W.
> >>'66 HCS Mustang 289
> >>'68 Ranchero 500 302
> >>'69 Mustang Sportsroof 351W
> >>ThunderSnake #57
> >>http://home.comcast.net/~vanguard92/
> >
>
> --
> Wound Up
> ThunderSnake #65
>
> AHPBBFM pages: http://tinyurl.com/9yulk