I was wondering if someone could enlighten me to the main difference and possible benefits between a 186 head and a 161s head?
I think that they used to put the 161s on a 186 for the GTR's (?). So, does this up the compression? or do they just flow better?
Also, can you still get 161s heads from anyone who re-does them for unleaded?
Cheers
Moose
186 v 161s?
Started by
_Moose lc_
, Mar 05 2012 06:54 PM
6 replies to this topic
#2
yel327
-
- Members
-
- 13,711 posts
Oh My, Don't you post alot
- Joined: 10-February 08
Posted 06 March 2012 - 06:22 AM
161H and S engines used a small chamber head, 186 used a large chamber head. XU-1 186 and 202 used the 161 head, will give you pretty high compression.
#3
_Moose lc_
_Moose lc_
-
- Guests
Posted 06 March 2012 - 07:58 AM
Okay. Cool. Next question.......... Do I want or need that? It's going to be an everyday driver for cruising on weekends. Higher compression will make it punch a bit harder? Or will it just be overkill for what I want?
Cheers
Moose
Cheers
Moose
#4
wot179
-
- Members
-
- 6,784 posts
Green Eggs and Spam
- Name:Jesus Bloody Christ
- Location:Sunny Santa Maria
- Car:Goon
- Joined: 06-February 09
Posted 06 March 2012 - 08:24 AM
It will be fine.
Just use premium juice.
Just use premium juice.
#5
yel327
-
- Members
-
- 13,711 posts
Oh My, Don't you post alot
- Joined: 10-February 08
Posted 06 March 2012 - 09:12 AM
I wouldn't do it without a cam with a bit of overlap. It'll be about 10:1 or more static compression. And make sure your dizzy is setup right or it'll ping it's t!ts off. XU-1's ran less advance than a normal 186 or 202 from memory.
I'd just go any buy the head below (or similar). Get hold of a 186S inlet manifold and Carby or use a Falcon 2 barrel Weber. Extractors and good exhaust, regraphed blue motor HEI dizzy and a mild cam suited to the gearbox/stall and diff ratio. ANd run on 98 octane fuel.
http://www.ebay.com....=item4ab4c7287e
I'd just go any buy the head below (or similar). Get hold of a 186S inlet manifold and Carby or use a Falcon 2 barrel Weber. Extractors and good exhaust, regraphed blue motor HEI dizzy and a mild cam suited to the gearbox/stall and diff ratio. ANd run on 98 octane fuel.
http://www.ebay.com....=item4ab4c7287e
#6
_Mike73_
_Mike73_
-
- Guests
Posted 06 March 2012 - 10:47 AM
Hello Moose,
I ran a 186 fairly much set up as Yel327 suggests and I could achieve 30MPG on a country run if driven carefully, though that wasn't too often.
Mine was in a LJ 4 door and it went quite well, it had blue engine rods, balanced, Yella Terra head, std flywheel, 20- 60 cam and extractors driven through All Aussie 4 speed, & 3.08 diff, I did try a 2.78 diff but it made no difference to fuel consumption but made a bit hard towing with a M21 so I dropped down a couple of ratios to a M22.
The Yella Terra head was a large chamber, I wouldn't run a small chamber as they don't flow as well as a large chamber, contrary to your belief, and ports are normally the same between std heads though the HR 186 head is a bit less restrictive in the exhaust port area.
If you need to change your compression ratio I found that .010 planed off a large chamber 186 head took the compression to 175 PSI but this depends if your have the correct flat top pistons and how far it is bored.
Mike
I ran a 186 fairly much set up as Yel327 suggests and I could achieve 30MPG on a country run if driven carefully, though that wasn't too often.
Mine was in a LJ 4 door and it went quite well, it had blue engine rods, balanced, Yella Terra head, std flywheel, 20- 60 cam and extractors driven through All Aussie 4 speed, & 3.08 diff, I did try a 2.78 diff but it made no difference to fuel consumption but made a bit hard towing with a M21 so I dropped down a couple of ratios to a M22.
The Yella Terra head was a large chamber, I wouldn't run a small chamber as they don't flow as well as a large chamber, contrary to your belief, and ports are normally the same between std heads though the HR 186 head is a bit less restrictive in the exhaust port area.
If you need to change your compression ratio I found that .010 planed off a large chamber 186 head took the compression to 175 PSI but this depends if your have the correct flat top pistons and how far it is bored.
Mike
#7
_Moose lc_
_Moose lc_
-
- Guests
Posted 08 March 2012 - 10:49 PM
Thanks for that mike. I didn't actually know either way about the flow of the head. I've never had anything to do with the 161 engines and just wondered why they had been used on the 186 block. Doesn't sound like I'll need anything like that because I'm not planning on racing it in the least. A bit of fuel economy would be nice but I'm realistic, if I wanted economy I would be driving a bloody Prius. Lol
I think a plain old 186 will be the ticket for me. Fortunately I've got 2 186's, a set up with a 350 Holley and a set up with triple SU's, so if I get tired of one I can always swap it out and use the other. Simple as that right? Rofl!
Cheers
Moose
I think a plain old 186 will be the ticket for me. Fortunately I've got 2 186's, a set up with a 350 Holley and a set up with triple SU's, so if I get tired of one I can always swap it out and use the other. Simple as that right? Rofl!
Cheers
Moose
1 user(s) are reading this topic
0 members, 1 guests, 0 anonymous users
