Javascript Disabled Detected

You currently have javascript disabled. Several functions may not work. Please re-enable javascript to access full functionality.

Head Talk

Started by Stedz_lc , Dec 29 2005 08:34 PM

Please log in to reply

15 replies to this topic

#1 Stedz_lc

Forum Fixture

Members
1,144 posts

Joined: 10-November 05

Posted 29 December 2005 - 08:34 PM

Hey All
Just started strippin the 186 for a rebuild/gas setup n have found its got an odd head, well od to me it has the bridge rockers :S Whats the go there ? I thought only the Blue/black 202's had bridge rockers what other motors had these heads? This six has been rebuilt a few times id say, a mate gave it to me n he has no clue of its passed so i dont know what this head has been or done! Thou it was obviously a yella terra mock up at some time got the yellow paint on her hehe
Thanks for any help got me curious! I think ill goto the 138 head anyway
Cheer
Stedz

Back to top

#2 _draglc_

Guests

Posted 29 December 2005 - 08:56 PM

Red 202s had bridged rockers too.. but i cant imagine why theyd be on a 186??

Back to top

#3 _Flamenco_

Guests

Posted 29 December 2005 - 09:05 PM

My 173 has them but it was rebuilt before I had it (for use on gas)...

Back to top

#4 surfmaster

Marineboy

Moderators
2,019 posts

Location:Nowra N.S.W.
Joined: 08-November 05

Posted 29 December 2005 - 09:06 PM

I thought the bridged rockers (non-adjustable type) started in the LC 173's and then into the LJ & HQ series engines.

Back to top

#5 _Bomber Watson_

Guests

Posted 29 December 2005 - 09:45 PM

yeah, my 173 had those bloody sluts of things till i put on a diferent head...i can finaly adjst my rockers wtihout having to get the grinder lol.

Back to top

#6 Stedz_lc

Forum Fixture

Members
1,144 posts

Joined: 10-November 05

Posted 29 December 2005 - 10:32 PM

Yea i dislike them too!! Im goin to a 138 head being on gas i can really up the comp!! Only concern is this head maybe be a yella terra or somthing highly doubt it.. plus im guessin they wouldn't make it have bridged rockers either haha
Cheers
Stedz

Back to top

#7 _CHOPPER_

Guests

Posted 02 January 2006 - 02:11 PM

Only the 173/202 and 253/308 heads had the bridged rockers from the factory.

Back to top

#8 _gstar_

Guests

Posted 04 January 2006 - 09:28 PM

amyone who knows a bit about heads, in your opinion would a red 202 head be better than a 161 head on a 161 motor with a 30/70 cam with 1 3/4 su carbs. and also what colour was a 161 block? red>? i am not going to modify the head at all due to expectation of large costs.

Back to top

#9 FastEHHolden

Steptoe

Members
5,114 posts

Location:Central Coast NSW
Joined: 16-November 05

Posted 05 January 2006 - 09:20 AM

202 head...the 161 has smaller valves.

Back to top

#10 _CHOPPER_

Guests

Posted 05 January 2006 - 05:36 PM

The Red heads from 149 - 202's were once quoted as having valves that were " one size fits all ".

Back to top

#11 _revmaniac_

Guests

Posted 05 January 2006 - 06:11 PM

Red 202s had bridged rockers too.. but i cant imagine why theyd be on a 186??

might have been put on to lower the compression to avoid detonation.....if red heads have been machined a bit they can sometimes bump the compression up too far....specially when the new shit fuel wants to carbon up the chambers like a SOB

Back to top

#12 _CHOPPER_

Guests

Posted 05 January 2006 - 06:19 PM

179,186 & 202 heads all have the same combustion chamber volume.

Back to top

#13 FastEHHolden

Steptoe

Members
5,114 posts

Location:Central Coast NSW
Joined: 16-November 05

Posted 07 January 2006 - 08:38 PM

According to 2 different reference books EH HD HR (so therefore 149, 161, 179 and 186) have an inlet valve head size of 1.490 inches or 37.846 mm and an exhaust valve measuring 1.275 inches or 32.385 mm.

Then in the gregories vh book it lists inlet at 41.12 mm and exhaust at 35.74 mm

I know that the VH is blue motor so i should have clarified that before I posted before...does someone with a manual covering 202 have the valve head size?

Back to top

#14 _CHOPPER_

Guests

Posted 07 January 2006 - 08:47 PM

Red 130/138/161/173/202 valve sizes:

Exhaust valve head diameter: 1.271 - 1.281"
Inlet valve head diameter: 1.488 - 1.498"

Edited by CHOPPER, 07 January 2006 - 08:49 PM.

Back to top

#15 _gstar_

Guests

Posted 26 January 2006 - 05:10 PM

202 head...the 161 has smaller valves.

The Red heads from 149 - 202's were once quoted as having valves that were " one size fits all ".

um so the 161 is the same? but has higher comp? i dont know what i should be looking for.

chopper?

202 head...the 161 has smaller valves.

The Red heads from 149 - 202's were once quoted as having valves that were " one size fits all ".

um so the 161 is the same? but has higher comp? i dont know what i should be looking for. so do i keep the 161 head but look at putting bigger valves innit?

chopper?

Edited by gstar, 26 January 2006 - 05:12 PM.

Back to top

#16 _CHOPPER_

Guests

Posted 26 January 2006 - 05:40 PM

Putting a 161 head onto a 202 will bump your compression to around 10.5:1. If you have as huge cam ( 30/70 isn't huge ) or using Avhas, this should be fine. As I said: