CRG Discussion Forum

Camaro Research Group Discussion => Decoding/Numbers => Topic started by: Jcdubs on January 27, 2019, 12:46:53 AM

Title: 186 heads
Post by: Jcdubs on January 27, 2019, 12:46:53 AM
I have a set of 3927186 heads I can't find any information on.
 They are date coded E278 and E298
Here is the kicker, thay are angle plug heads.
Title: Re: 186 heads
Post by: Jcdubs on January 27, 2019, 01:02:40 AM
(https://www.camaros.net/showroom/data/531/medium/20190126_183134.jpg)
(https://www.camaros.net/showroom/data/531/medium/20190126_194056.jpg)
(https://www.camaros.net/showroom/data/531/medium/20190126_194016.jpg)
Title: Re: 186 heads
Post by: firstgenaddict on January 27, 2019, 03:12:10 AM
I think you will find that they are plugged and redrilled... I had a set which I got with some parts back in the early 90's.
 186's use the larger flat seat plug with the 13/16 hex.
Title: Re: 186 heads
Post by: Emo1956 on January 27, 2019, 03:54:08 AM
Ya someone made them that way .
Title: Re: 186 heads
Post by: dannystarr on January 27, 2019, 05:40:19 AM
So that would be May 27th & 29th 1968? Danny
Title: Re: 186 heads
Post by: Jcdubs on January 27, 2019, 01:24:22 PM
Can't imagine going through all that and leaving press in studs.
The date is odd to?
I have had these to 25 years, trying to thin out the hoard,lol
Title: Re: 186 heads
Post by: Jcdubs on January 27, 2019, 01:45:56 PM
Upon closer inspection you are absolutely right.
They were filled and drilled.
They did a nice job, for what gain who knows.

Title: Re: 186 heads
Post by: BillG on January 27, 2019, 03:26:21 PM
Header clearance mabey?
Title: Re: 186 heads
Post by: z28z11 on January 27, 2019, 04:47:42 PM
If I was really energetic I would look back through my old Hot Rod mags and find the article for the company that made the kits to plug the original plug holes and redrill with the angled small plugs, which mimics the configuration that GM started in the early 70's (better flame pattern during combustion in the chamber). Screw-in inserts and a drill bushing/fixture to drill the holes, wish I could pinpoint the year and look it up. My Hot Rod subscription started in '70, still have them all (like an idiot) up until 2005, give or take a year or so. 

Regards,
Steve
Title: Re: 186 heads
Post by: firstgenaddict on January 27, 2019, 11:11:29 PM
Can't imagine going through all that and leaving press in studs.
The date is odd to?
I have had these to 25 years, trying to thin out the hoard,lol

I would have to agree on that...
The pair I had - were 292's - with screw in studs, guide-plates, doublesprings w/dampers - fully ported, and polished D-shaped Exhaust ports- gasket matched on the intakes through the throats and pockets with the chambers smoothed of sharp edges- bronze guides - Teflon seals -  2.05 intake valves, swirl polished with undercut stems, titanium retainers, & 10deg locks.
Title: Re: 186 heads
Post by: Emo1956 on January 28, 2019, 01:04:59 AM
The angle plug was pointed toward the exhaust valve for better burning of the combustion chamber which made more HP. This is a set of 292 turbo heads that was run in NASCAR and then I ran on my dragster. I still have these heads. They made a lot of HP
Title: Re: 186 heads
Post by: 69Z28-RS on January 28, 2019, 03:15:09 AM
If I was really energetic I would look back through my old Hot Rod mags and find the article for the company that made the kits to plug the original plug holes and redrill with the angled small plugs, which mimics the configuration that GM started in the early 70's (better flame pattern during combustion in the chamber). Screw-in inserts and a drill bushing/fixture to drill the holes, wish I could pinpoint the year and look it up. My Hot Rod subscription started in '70, still have them all (like an idiot) up until 2005, give or take a year or so. 

Regards,
Steve

One 'like an idiot' to another.. :) ..  I Have THOUSANDS of Car magazines (back to around 1978)  I finally stopped HRM, CC, and PHR a few years ago but all those magazines organizes mostly by year/name.  I need to let them go, but can't imagine trashing them!  Woe is me...   :(
Title: Re: 186 heads
Post by: mrk69 on January 28, 2019, 04:12:01 AM
You might want to check with an area auto museum. Many have automotive related libraries that would welcome donations of collections like this. I gave mine to the Gilmore Car Museum in Michigan.
Title: Re: 186 heads
Post by: firstgenaddict on January 28, 2019, 02:47:21 PM
They were canted toward the exhaust because that is typically where preignition occurs- thus if you fire the plug closer to the preignition points "HOT SPOTS" -  you are less likely to have colliding flame fronts(detonation) which will destroy the engine. 
 
DETONATION is the collision of two flame fronts inside of the cylinder.
I have a book which shows photos taken by GM through a quartz lens of the entire sequence. Twenty or so photos of what happens during a pre-ignition situation illustrated in crank degree BTDC and ATDC.
Title: Re: 186 heads
Post by: Jcdubs on January 28, 2019, 05:11:37 PM
Thanks guys,
 I guess the next question is there any worth in these dinosaurs, since they have been modified?
Title: Re: 186 heads
Post by: z28z11 on January 29, 2019, 02:14:45 AM
If I was really energetic I would look back through my old Hot Rod mags and find the article for the company that made the kits to plug the original plug holes and redrill with the angled small plugs, which mimics the configuration that GM started in the early 70's (better flame pattern during combustion in the chamber). Screw-in inserts and a drill bushing/fixture to drill the holes, wish I could pinpoint the year and look it up. My Hot Rod subscription started in '70, still have them all (like an idiot) up until 2005, give or take a year or so. 

Regards,
Steve

One 'like an idiot' to another.. :) ..  I Have THOUSANDS of Car magazines (back to around 1978)  I finally stopped HRM, CC, and PHR a few years ago but all those magazines organizes mostly by year/name.  I need to let them go, but can't imagine trashing them!  Woe is me...   :(


It's a good thing magazines have no inherit magnetism - if that was any different, true magnetic north would be pointing at Tennessee for all the Hemmings, Super Chevy, HRM, and others stored here. Downright fire hazard -

Steve
Title: Re: 186 heads
Post by: z28z11 on February 14, 2019, 02:09:57 AM
For those of you that considered me to be insane, presto ! I knew I could find it if I looked long enough. Now, if i could only find the article that showed how this was done, I'd feel vindicated -

Regards,
Steve