164 compression ratios

john h · Jun 27th, 2009, 08:15

Hi

The 164E (B30E) had a higher compression ratio than the 164 carb.

Can anyone tell me definitively how Volvo was achieved this?

(I am considering lowering the CR of my B30E prior to supercharging it and I'm looking for a cost effective way to do it).

Thanks

John

classicswede · Jun 27th, 2009, 11:10

The E head is thinner than the carb head. If you fit a E head you have to use the E bolts as the carb bolts bottom out and don't hold teh head down!!!

To increase the CR it is simply a case of skimming the head and obtain some E head bolts.

john h · Jun 27th, 2009, 20:55

Quote:

Originally Posted by classicswede

The E head is thinner than the carb head. If you fit a E head you have to use the E bolts as the carb bolts bottom out and don't hold teh head down!!!

To increase the CR it is simply a case of skimming the head and obtain some E head bolts.

Thanks...

Is the design of the E head different (e.g. combustion chamber shape, ports, valve sizes)?

Or is an E head the same as a carb head, but just skimmed down and with holes drilled for the injectors?

Also, are carb and E pistons the same?

John

classicswede · Jun 27th, 2009, 23:34

Carb and E pistons are the same.

The E and the late heads are fitted with the bigger inlet valves as per the B20E - these could be retro fitted.

Ports all the look the same but combustion chamber may be slightly changed but I doubt it.

B20F · Jul 8th, 2009, 20:34

On the B20E&F the cumbustionchamber is a little oval shaped. You can notice this from the headgaskets. The B20A&B cumbustion chamber holes are round as the B20E&F are oval. I think the same goes for the B30E&F. You can use the 1,2mm F gasket as the E is 0.8mm. Will help some but not much.

john h · Jul 12th, 2009, 12:26

Thanks.

I don't want to use a thicker head gasket, because this reduces the effectiveness of the squish area and can lead to more, rather than less, predetonation.

No final decision yet, but my current thinking is to use B30 carb head (CR 9.3:1), gas-flowed and with bigger valves fitted. I could either have the head machined to accept the original injectors, or have the inlet manifold machined to fit modern type injectors.

Any thoughts/suggestions?

John

B20F · Jul 12th, 2009, 12:44

Here's an interesting site about turboing a B20F in a 1800ES. Maybe usefull for a B30 too.

Jun 27th, 2009, 08:15	#1
john h VOC Member Last Online: May 30th, 2024 11:13 Join Date: Jan 2007 Location: Huddersfield View Photos By: john h	164 compression ratios Hi The 164E (B30E) had a higher compression ratio than the 164 carb. Can anyone tell me definitively how Volvo was achieved this? (I am considering lowering the CR of my B30E prior to supercharging it and I'm looking for a cost effective way to do it). Thanks John __________________ XX

Jun 27th, 2009, 11:10	#2
classicswede Trader Volvo in my veins Last Online: Today 00:14 Join Date: Dec 2004 Location: Anglesey	The E head is thinner than the carb head. If you fit a E head you have to use the E bolts as the carb bolts bottom out and don't hold teh head down!!! To increase the CR it is simply a case of skimming the head and obtain some E head bolts. __________________ http://www.classicswede.org www.classicswede.co.uk

Jun 27th, 2009, 23:34	#4
classicswede Trader Volvo in my veins Last Online: Today 00:14 Join Date: Dec 2004 Location: Anglesey	Carb and E pistons are the same. The E and the late heads are fitted with the bigger inlet valves as per the B20E - these could be retro fitted. Ports all the look the same but combustion chamber may be slightly changed but I doubt it. __________________ http://www.classicswede.org www.classicswede.co.uk

Jul 8th, 2009, 20:34	#5
B20F Master Member Last Online: Jul 7th, 2016 21:43 Join Date: Mar 2007 Location: Zeist View Photos By: B20F	On the B20E&F the cumbustionchamber is a little oval shaped. You can notice this from the headgaskets. The B20A&B cumbustion chamber holes are round as the B20E&F are oval. I think the same goes for the B30E&F. You can use the 1,2mm F gasket as the E is 0.8mm. Will help some but not much. __________________

Jul 12th, 2009, 12:26	#6
john h VOC Member Last Online: May 30th, 2024 11:13 Join Date: Jan 2007 Location: Huddersfield View Photos By: john h	Thanks. I don't want to use a thicker head gasket, because this reduces the effectiveness of the squish area and can lead to more, rather than less, predetonation. No final decision yet, but my current thinking is to use B30 carb head (CR 9.3:1), gas-flowed and with bigger valves fitted. I could either have the head machined to accept the original injectors, or have the inlet manifold machined to fit modern type injectors. Any thoughts/suggestions? John __________________ XX

Jul 12th, 2009, 12:44	#7
B20F Master Member Last Online: Jul 7th, 2016 21:43 Join Date: Mar 2007 Location: Zeist View Photos By: B20F	Here's an interesting site about turboing a B20F in a 1800ES. Maybe usefull for a B30 too. __________________

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