[ho428]

I've been testing the 365 with KRE heads and notice it takes much longer to get the engine up to temperature. It does not run or idle very good below 1200 until it gets to around 150+, once warm it idles nicely around 900.
Is this normal for Aluminum heads?

11:1, running 110 octane, 16 lb radiator cap and 180 stat. T-2, Holley 750 DP, no choke, no crossover, solid lifter cam.
With the Iron heads it warmed up much faster, and idled ok when cold, but lower compression and it did have a milder hyd cam and a crossover then but still no choke.

[BruceWilkie]

FWIW I think too much octane is most of your problem.

[ho428]

Sent you an email Bruce.

I'd been mixing 110 with 93 but ran low last time at the track, 110 was all they had on hand, still have about 1/4 tank (22 gal cell) to finish off.
I'd like to be able to run less octane, save some money for sure, I go through about 25-30 gallons for a two day event. Problem is taking enough with me. One track has 100 and up most times, the other has 110 and up. A 100 and 93 mix I tried did fine with the Iron heads, I see no reason it shouldn't with the new aluminum heads.
If I fill the cell and my can it's barely enough at one track, but I don't like running the car completely full. We run 10-12 lap stints with about an hour+ between sessions.

[440GP69]

Straight 92-93 octane! 11-1 with KRE's heads is easy on premium, 110 Has got to be a little hard to ignite! like running Diesel in a gas engine!

[ho428]

I wish the tracks had 93 but they start at 100 and go up from there. I've 1/2 filled the cell before at the local station with 93 and added about 1/3 more 100 at the track using Iron heads and it ran great. The 110 was just all I could get last time out so I need to burn it out.
I'll get another gas can and start taking more 93 in with me I guess. That'll give me 10 gallons, with a 3/4 full cell to start that should about do it.

Now when I run low and need to top off but only have a few gallons of 93 with me if people ask if I'm trying to raise the octane I can say no, actually trying to lower it

Never thought the octane would effect the temp so much. The longer warm up time was not something I expected though. Thought it'd be about the same since the compression is up and the cylinder fill should be higher due to flow and cam changes.
But then again, this is my first Aluminum headed Pontiac. Learning curve.

[BruceWilkie]

Originally Posted by 440GP69

Straight 92-93 octane! 11-1 with KRE's heads is easy on premium, 110 Has got to be a little hard to ignite! like running Diesel in a gas engine!

Based on my snowmobile experience if a sled was speced for 87-89 octane cold starts with 93 or higher sucked and tended to foul the plugs. Once warmed up if the plugs stayed clear it seemed to make no noticeable difference in performance(though I never clocked it).

I generally agree with what you're saying however hes running the infamous "CliffR solid cam" Comp XTQ with only 269/278 seat time (240/248 at .050)112LSA on 110 ICL. I dont remember for sure but the dynamic compression was around 8.7 using seat time and 9.7 using .050 timing. Imo a little more than 93 octane wouldnt be a bad thing. Just seems 110 is overkill.

I let Gorden use the cam I bought from Cliff as it seemed a better match for his road race 364 vs Cliffs 462. It certainly looks better in the 364 than a 462 when you compare them on the Sim. I havent had a good home for it myself so I offered it to him to try. We will soon see how it fares over his old fireball solid. He should have a lot more tq coming off the corners and a nice fat power curve to compliment his wide ratio 4 speed. Combined with the KRE 290's fitted with 2.07/1.66 exhaust a T2 and 750 running in a 6500-7000 rpm limited class I think hes got an edge. (unless the sbc boys get a clue and stuff a 400 sbc crank in a 283/307 block)

IMO the SBC boys arent going to like him anymore. Pontiac power!

[v869tr6]

If the 110octane isblended for summer use and its cold now, that could be part of the problem. Winter gas has a bunch more lite ends to help vaporize the fuel in cold temps.

[taff2]

I used to get a similar thing when I ran a high percentage of toluene,especially in cold weather. I used to run it at a fast idle for a couple of minutes then shut it off to let heat soak into the manifold.

[Dragncar]

Is it a 364 or was that a error and its a 465.
Generally the smaller the engine the less the need for octane.
As in a 400 and a 455 can have the same static CR but the 455 will develop more cylinder pressure thus be more prone to detonation.
And its cylinder pressure, not CR that matters. Cylinder pressure is EVERYTHING in performance.
If it is a 365ci engine, with aluminum heads and 11.1 CR 110 octane seems very high.
You would not need 110 octane with a 465 engine with aluminum heads and a big radiator much less a 365.
I dont know if high octane is much harder to ignite than premium either. But there is more BTUs in regular than premium. More heat = more energy.
If a engine will not ping with premium it will run slower with race gas.
There is more energy(more power,more heat) in regular unleaded than the best race gas.
The reason race gas engines make more power is they allow the engine to make more cylinder pressure without lighting it all off before the piston reaches the top.

[gtoroadracer]

I am not running a thermostat but with my set up it will hold a decent idle once it gets about 180 on the water temp gauge. Even though the motor you have with the aluminum heads will run fine on 93 octane it should be suggested that you run a higher octane. Since it is a road race car the revs are going to be high for a long period of time. The cars is probably going to do the equivalant of 30 to 40 drag race runs on your 30 minute track time. Having the extra octane will help.

[bobzdar]

It takes a while for my car to idle nicely, solely due to the blocked crossover and no choke in my case. With the crossover active it would idle on its own in 30 secs to a minute. With it blocked, it's usually minimum 3-4 minutes of babysitting it when cold. Iron heads, 10:1 compression in my case.

What you can try doing is re-curving the dist. to give you less advance at idle and run ported vac. advance. Less timing with no load should generate more heat and help it get hot faster. Then run a fast curve and ported advance so in normal driving it won't lose efficiency. As an experiment, set the initial to something low, like 6 btdc and unplug the vac advance. You'll have to turn the idle way up and it'll probably lope a lot but it should heat up noticeably faster (and probably burn your eyes). I personally just sit in the car until it's ready, I find it warms up faster if I tap the pedal to go between 1000-1700rpm instead of holding a steady (1500) rpm. Stands to reason as burning more fuel should get the heat in it faster.