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#76 |
Board Member
Join Date: Jan 2022
Location: Geneva, NY
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![]() No worries. It's in my garage and off the road for Dec, Jan, and Feb every year. When it ventures out at all during those months, it's only when the roads are dry and only for test runs. The head will come out next week, so it won't be going anywhere until the new head is installed and tested.
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#77 |
Board Member
Join Date: Nov 2002
Location: Sweden
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![]() Before you shave the head, make sure it has not been shaved before, I mean car is soon 30years...
If I recall correctly it is suppoaed to be 146.1mm between headgasket surface and valve cover gasket surface as stock.
__________________
White car: --744 GLE ´88-- Polishing object Black car: --S80 V8 ´07-- Daily driver www.garaget.org/JE_Jr |
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#78 |
Board Member
Join Date: Jan 2022
Location: Geneva, NY
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#79 |
Old and boxy but good.
Join Date: Jun 2002
Location: S NJ, a suburb of Phila.
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![]() I would suggest you read up about tight squish if you are going to remove the head. It will help avoid the chance of detonation with the higher than stock compression from shaving the head.
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Dave, 1982 242 turbo. 338k miles. MVP coilovers and 3" exhaust. Flowed 405 with a V15. Cossie turbine housing with upgraded compressor housing. 90+, IPD remote oil filter. Some other goodness, too. Been lots of fun over 25 years. Restored in 2k. Now ready for a 2nd restoration. 1993 245 Classic, 435k miles, enem V15. IPD bars and chassis braces. Simons sport exhaust from Scandix. sbabbs ezk chip. Been a good road warrior. Genuine Volvo rebuilt leaky M47. ![]() |
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#80 | |
Board Member
Join Date: Jan 2022
Location: Geneva, NY
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![]() Quote:
I'm probably missing something here. What is it? Perhaps I should just fuel it with 93 octane and declare victory. |
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#81 |
Board Member
Join Date: Jan 2022
Location: Geneva, NY
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![]() *BING* The lightbulb is lit!
OK, got it: aim to get the piston tops closer to the head for optimal cooling of the piston tops by either resurfacing the block or using a modestly thinner headgasket. I just found and read a wonderfully entertaining pissing match on this forum over the terms "squish" and "quench". Thank you, John V, outside agitator for enlightenment. Sometimes dawn comes late in my part of the world. |
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#82 |
Board Member
Join Date: Jan 2017
Location: San Clemente
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![]() Turbo would be more fun. After all this is TURBObricks, not NormallyAspiratedBricks. =)
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#83 |
Board Member
Join Date: Jan 2022
Location: Geneva, NY
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#84 |
Old and boxy but good.
Join Date: Jun 2002
Location: S NJ, a suburb of Phila.
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![]() Glad you got the idea of the tight squish/quench. You won't need to deck the block. Just measure the piston height and calculate the head gasket thickness needed. The MLS head gaskets are available in several thicknesses. This helps a lot with detonation resistance and efficiency of combustion.
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#85 |
Board Member
Join Date: Jun 2009
Location: Swampscott, 01907
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![]() They're nowhere near 9.8:1 as delivered. Mine measured out to 9.1:1. After a 0.040" mill and stock head gasket, it's 9.8:1. I use a V cam and feed it a steady diet of Shell 87 (R+M)/2 and have no detonation issues. Using 93 netted no measurable improvements of any kind.
__________________
I AM THE MODAL AMERICAN. Planet money #936. |
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#86 | |
Board Member
Join Date: Jan 2022
Location: Geneva, NY
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![]() Quote:
Anyone else lurking here have a similar or different experience???? I guess I could measure compression on my motor now for a reference point, but that would only indicate absolute compression on a motor and head with 150K miles, and before a valve job and shaving. |
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#87 |
Board Member
Join Date: Jul 2016
Location: MA/NH
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![]() I've also measured two uncut late NA 530 heads (93 and 94 castings) at 54cc and change which math's out to the low 9's to 1 depending on the piston height.
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1991 244 LH3.1 M46 393k miles |
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#88 | |
Board Member
Join Date: Jun 2009
Location: Swampscott, 01907
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#89 | ||
Ronald Culberbone III
Join Date: Feb 2010
Location: Redmond, OR
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![]() Quote:
![]() I’m pretty sure Volvo left out the HG volume when they did the calculation for publication. My experience with 87 vs 91 may be different (it overall doesn’t really matter), but the CR thing is real 100%
__________________
Cult Person. Pissing in your Kool-Aid. Quote:
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#90 |
Board Member
Join Date: Oct 2016
Location: Oregon
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![]() Anyone know about the higher comp B23F engines? I have one in my 83, it's apparently 10.3:1, but maybe they also left out the HG?
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#91 |
Moderator
Join Date: Mar 2003
Location: Monroe, OR USA
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#92 | |
Fanking Champion 1993
Join Date: Jan 2015
Location: College Station, TX
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![]() Quote:
He's a weird one, but that particular Mr Grinch certainly knew his sh1t. |
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#93 | |
Board Member
Join Date: Jun 2009
Location: Swampscott, 01907
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![]() Quote:
The truth is out there. Just like on X-Files. |
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#94 |
Board Member
Join Date: Oct 2016
Location: Oregon
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![]() I remembered that, I'm just curious if somone has done a CC fluid test on the B23F heads to check for spot on accuracy. I do recall my compression readings being pretty high when I did a comp test.
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#95 |
Board Member
Join Date: Jan 2022
Location: Geneva, NY
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![]() Just for fun, I warmed up the engine and ran a compression test.
1= 132 psi 2= 138 psi 3= 138 psi 4= 140 psi Assuming an atmospheric pressure of 14.696 psi, a 9.1:1 compression ratio works out to 133.7 psi It fits. Not bad for an engine with 145,000 miles. I'll post the new numbers after the head is shaved. |
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#96 |
Ronald Culberbone III
Join Date: Feb 2010
Location: Redmond, OR
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![]() Those are really low numbers for cranking pressure on a warm NA motor.
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#97 |
Board Member
Join Date: Jan 2022
Location: Geneva, NY
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![]() What am I missing in my assumptions? A temperature effect of compression in PV=nRT? It was a "dry" test (no oil added to cylinders).
Last edited by dmg4; 01-30-2022 at 08:30 AM.. |
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#98 |
Single jingle
Join Date: Aug 2016
Location: Granby CT
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![]() Even with a VX cam?
__________________
I don't know what I have |
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#99 |
Board Member
Join Date: Jan 2022
Location: Geneva, NY
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#100 |
Single jingle
Join Date: Aug 2016
Location: Granby CT
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![]() It matters. My engine makes like 120psi cranking compression with the IPD turbo cam. A stock stock one would make 160+
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