147 replies to this topic

[Uncle Chop Chop]

Thats because of the very different characteristics of methanol, nothing to do with the octain number or compression ratio...

No arguement there, it was more a reply to the following comment:

as High Compression creates Hotter water

[N/A-PWR]

Thank-you Vick, Bomber Watson, tryhard and ljxu1torana,
So now we have more information on the 14:1 CR subject to debate, as I see it now is if the original question was 14:1 cr static or dynamic compression pistons?
My guess it was static as the turbo-ed 186 proves the 14.1:1 dynamic cr at full power with the duration of the cam.
With the previous links to high cr's state to have a cooler combustion temperatures using cooler fuels, coated ( valves, combustion chamber and pistons ) which helps to keep the detonation further away, having said that, static 14:1 cr could well run on 98+ gasoline with the XU1 Cam's duration could well bring the dynamic cr to 9:1 ( that was a guess ).
I would also say that I achieved 250psi cylinder pressure using a 41/78 solid cam I bought from Rare Spares at the strathfield branch.
So here we are attempting to have a normally aspirated engine with a new comp high reeving 41/73 cam duration at a dynamic 9:1 cr.
If the cr was a dynamic 14.1:1 ( be like driving with a Turbo or supercharger on boost all the time ) then the static cr would need to be 17:1 or so which would need some serious components.
Now as questioned earlier, 14:1 static cr is difficult to achieve or was that 14:1 dynamic cr difficult to achieve?
I say this, if we had no combustion chamber and the cam had a short duration, the static cr would be through the roof.
So in saying that the static 14:1 cr is achievable somewhere in between. Dave I

[Shtstr]

look at jag xjs lumpy tops and 253 lumpy tops as we looked at them years ago and they would fit but we never got around to building it.

[Dave6179]

Hi Dave6179,
Yes, when I was reading the High Compression article I was thinking there is a lot of components to improve on,
and by the sounds of reducing the water temperature,
as High Compression creates Hotter water your engine should be at the right Temperature, if that makes sense. Dave I

I remember some ... OK, a lot, of years ago, I was inquiring info on plugs. A mate of dads had a book on plugs and stuff, as he was an old mechanic. The book said the 202 XU1 ran at 210 degrees, with Champion N11YCs. I'm using the equivalent of N9s, but I found N7s are better for performance, however... since fitting the HEI, the plugs I was told to use may be too hot as well.

[N/A-PWR]

look at jag xjs lumpy tops and 253 lumpy tops as we looked at them years ago and they would fit but we never got around to building it.

Hi lcxu105,
Great info there, I had a look around on Google with no direct results yet.

Thank-you gmlj6,
I guess I am seeing what the enginners were up to in the late seventies.

Great Idea's there tryhard,
I may not blow this thing up.

Yep Dave6179,
I just used N9Y's in the 186 head, but we are entering into a new field now - I had a Champion spark plug Mentor as he worked for them for the later part of his life - has passed now.

Great inputs here, now we need a strong bearing set to go with it. Dave I

[N/A-PWR]

OK Readers,
I have come across this Write up Link about Compression if You would like to comment on:-

http://www.popularho...io/viewall.html

As it tell us more about compression in different ways.
ie - How good does your compression seal etc. Dave I

[Dave6179]

I changed the thermostat to a 160 three days ago. Now runs up to 180, was getting up to 215 (everything is new and clean so must be something else making her run hotter), but does pull better! Just took it for a 200km trip yesterday, nearly 30 degree day, with all the family. Was pulling 160km/h (ssshhh) with ease, and loads more waiting. Was only 4000rpm/5th. Cam starts working at 3300.

[N/A-PWR]

Hi Dave6179,
Great to see part of the Heating sorted, do you have a triple core radiator?
I use the V8 HQ as it has the hoses in the right place for the Six. Dave I

[N/A-PWR]

p.s. when I was doing 80mph continually, the Six would over heat, after putting the V8 HQ Copper Radiator in, it was all fixed.

p.p.s. I heard the Aluminium Radiators are not good for cast iron Engines because of the Internal Flakes.

[Shtstr]

Where your temp gauge goes into the head at the rear. Put in a t pice and run it back to the thurmastat houseing. will drop the temp a bit more and help the number 5 and 6 cyl. we use to run it to a mini radiator then back to the thurmostat houseing in the race cars and never had any heating problems what so ever. Even after 50 laps of holding it flat out only hit max of 85 deg.

P.S we also cliped the blades of the water pump to slow down the flow and only used a restrictor plat insted of a thurmostat.

[N/A-PWR]

Great Information lcxu105,
Nice to see another way to deal with cooling, what size Radiator did you use?

[Stinga]

p.p.s. I heard the Aluminium Radiators are not good for cast iron Engines because of the Internal Flakes.

a filter would stop that

http://www.tefba.com/

[N/A-PWR]

a filter would stop that

http://www.tefba.com/

That is just what we need - thank-you Stinga.

[Dave6179]

Hi Dave6179,
Great to see part of the Heating sorted, do you have a triple core radiator?
I use the V8 HQ as it has the hoses in the right place for the Six. Dave I

I do have a brand new V8 rad, had it in for a while to check it's performance... didn't make much difference. It's screwed to the shed wall at the moment, but after making more changes recently I might chuck it back in.

[N/A-PWR]

Just Found these High Compression Piston Gems:-

 

 $_57.JPG   230.99K   3 downloads

http://cgi.ebay.com....em=281344861249

 

I wonder if we can use them in a 208ci as the Rods would need to be different. Dave I

[SA EH]

Have you considered 253 lumpy tops Dave?

[N/A-PWR]

All New to me Jonesy,

I would LOVE to have Lumpy's in a Red 208. Dave I

or a Blue 208 Short Motor even

just need to know the How Too's