[J.C.you]

Originally Posted by tpssonic

"realize this is the street section, but a cold intake under running conditions makes a case for runners to have this type texture."- J.C.you

Exactly! This "texture" promotes turbulence and additional atomizing/emulsifying of the charge. In dyno tests (again, 2-stroke engine-speak spoken here, but it should apply to similar internal combustion engines), we saw decrease in power FROM STOCK with (smooth-finish) extrude-honed intake ports. Roughen them up and bingo- increase in power from stock. More importantly, it helps both street and race engines.

another pic extended into the intake runners and chamber also. Meaux has done back to back tests, same engine, same heads/ intake package on the dyno. A average of 15HP was typical and he did not see one instance that power fell off with the mod. The ETs dropped respectively at the strip also.

[Cliff R]

I tried the same test about a week ago when it was -28 and the results weren't quite as good. It took 6-8 pumps with the gas pedal to get it to fire, and the engine stalled out several times as the choke pull-off opened the choke flap. Each time I re-fired the engine, it acted a bit better, then finally fast idled on it's own on the 4th or 5th attempt. I could have fine tuned the choke pull-off open angle for the scenario, but then it would have been a tad to rich for warmer conditions. As with most of these things, there is always some compromise.

I guess those are pretty decent results considering aluminum heads/intake, and how big the camshaft is. A working exhaust cross-over would have been a big plus to the deal, but the KRE heads aren't set-up for one.

The -28 degree test also prompted me to do an oil change, as it was pegging out the 80psi gauge for a couple of minutes till the oil heated up some. I dropped the 15W-40 and put in some 10W-30, not wanting to blow up the filter or shear the pump shaft testing this stuff in these extremes. On the second test this morning oil pressure was down to 77psi for the first few minutes, which made me a bit more comfortable during the testing.

On the same subject, my Quad (2011 Honda Rubicon) absolutely REFUSED to fire in those same conditions. Took me nearly half an hour that same morning to get it going....so much for "modern" technology......LOL.....Cliff

[tpssonic]

-28 F is inhuman. Plain and simple. I fell into a lake testing one winter (don't ask) when it was -15 (-40 F wind chill) and my pants froze solid from the time I get on shore until the time I walked to my vehicle parked very close to shore. No one or nothing should he asked to to anything at that temperature.


"On the same subject, my Quad (2011 Honda Rubicon) absolutely REFUSED to fire in those same conditions. Took me nearly half an hour that same morning to get it going....so much for "modern" technology......LOL.....Cliff"

We rest our case.

[Joel Koontz]

I'm not too concerned with how my Pontiac runs in below Zero Temps as it will be extremely rare that I start/run it when the temps are that low. I am interested in how it runs with temps higher than 30 degrees.

Has anyone ever tried putting any kind of electric heating element in/near the intake to assist with warm up. This would allow it to be fully turned off once the engine has warmed up and if the element is powerful enough it should significantly help warm up the intake.

Any thoughts on how powerful of a heating element would be needed? Would it draw more current than the alternator would supply at idle?

If there is any merit to this approach I could install the heating element in the exhaust crossover. Any suggestions on what heating element/s might work well?

[Kenth]

I think the Pontiac engine engineers already did the job for you to keep the engine at proper operating temerature?
You know, the intake crossover and the cooling system and such.
I wouldn´t worry about it.

[J.C.you]

one could always install a stealth MPFI, still leave a faux pas old qjet on top and fake it.

[68 Firebird]

Well figured I would throw my findings in as they seem inline with others.

-temp outside was 18 and same in garage. Car has not been started in a week
or so. New aluminum radiator installed along with reservoir.

-1 pump to set choke and she fired in a few cranks and climbed to high idle
in 10 or so seconds. Oil pressure shot to 60pi and yep my noisy lifter was
tapping for about 30 seconds.

-tapped throttle to come off high idle to next setting on cam and motor was
around 1250 rpms and exhaust crossover was 90 degrees and climbing.
motor was slightly twitchy.

-after 4 minutes idle had climbed to 1350 and crossover was 220 and motor
was smoother kicked off choke and idle was at 750rpm. smoother idle as temp
got to 180.

-Let her idle to tstat opened and she got up to about 800rpm in park and was very smooth
and healthy. exhaust crossover was around 235 and temp at tstat housing was 175.

-After 20 minutes idle oil pressure was 45 but usually will drop down to 25 after getting driven and hot. Not gonna happen today!!!!!!!

-in my car the crossover helps smooth out idle and found the thicker gasket from Cliff
was a good insulator to keep heat in the intake yet isolated from carb.

-I have driven mine in 40 degrees temp on long drives and she ran great just wanted
a larger radiator for the summer time.

Gerry

[Joel Koontz]

Thanks for the additional replies.

I agree that the system as designed by Pontiac worked pretty well for what it was intended to do, but I have different goals and non-stock parts.

My car is not driven every day of the year, and(at least while I have it) it never will be. I'm sure the Pontiac designers intended for the car to work OK, year round, in all of the lower 48 states, but it does not matter to me how well my car starts and warms up at temps below about 30 degrees.

I will occasionally drive my car on days where the temp will eventually get up to 50+ degrees, but the start up temp may be in the 30s. There will only be a few of these days per year and the great majority of my driving will be when temps are over 60 degrees.

I am convinced that I do not want any heat added to the intake when the ambient air temp is over 60 degrees and I more concerned with getting best performance at 60+ degrees than I am with it running less than optimally at lower temps.

I am seeking options that may improve how the engine initially runs when started in lower ambient temps, without increasing the intake temp when the engine is fully up to operating temp when the ambient air temperature is over 60 degrees.

Since I rarely start/drive the car in the cooler temps, I can "live with it the way that it is", but if there are things I can do for a modest cost I may consider them.

[Cliff R]

Your car is driven and used pretty much like mine is. Pretty rare that mine ever leaves the driveway between November and March, as the weather is crappy, roads salted down, etc.

To attain your goals, about all that is needed is a working choke, fast idle cam, and correctly adjusted choke pull-off. This will produce instant start-ups in all weather conditions, and fast idle so you don't have to "pat" the gas to keep it running.

The intake is going to heat up eventually on street driven vehicle, little that you can do about it, and it really needs to have some heat in it to offset the negative effects that have been discussed in previous posts.

On track days, if you race the car, a few minutes with the hood up between rounds will allow things to cool down a bit, but I would NOT recommend any steps taken to cool the intake specifically. Doing so will not produce consistent ET/MPH, especially if you are a good enough racer (or lucky enough) to start going rounds. As you get to final rounds, the track officials with start "hot-lapping" you back to staging, so there isn't enough time to get the engine cooled back down, at least nearly as well as you could have had it in early rounds.

These days I run my engine fully up to temp, and well heat-soaked. It runs quicker and more consistent than if attempts are made to cool it down between rounds....FWIW.....Cliff

[68 Firebird]

Agreed that most of our cars will rarely see the road this time of year.
Heck if it wasn't out of curiosity I wouldn't have fired up mine today.
Mine won't leave the garage for another 2 months of hibernation.
With or without a crossover is a preference and car can be tuned to run either way.
I tried to run a modified intake last summer that had water crossover separated and
exhaust crossover removed and found my car did not respond as I liked.
Running for 1/2 hour in an 80 garage the carb and intake were 60 degress!!
throttle response was same but had minor hesitation going deep in throttle.
Also when car was parked heat soaked had everything under hood same temp anyway.
Yes I can do some adj to get better results but just decided the unmodified intake gave
more consistent results regardless of weather.

Saving modified intake on shelf for when I go with KRE heads.

Good Luck

Gerry

[Tom Vaught]

Block heaters are good ideas if it is cold weather, like Michigan occasionally.

I plugged the flanges of an Aluminum Tri-Power intake. Removed about 2" on each side of the heat cross-over passage on each side. Made new side walls for the cross-over passage under the intake plenum and added heater water nipples (2 "IN" and one larger "OUT" nipple). The 2 "IN" nipples connect to the rear nipples on the E-Heads and the larger "OUT" goes to the water cross-over at the front of the manifold.

I plan on plugging in the Block Heaters before I fire the engine and that should warm up the water in the system (including the intake) for a solid immediate cold start on the Tri-Power. It should make the engine drive better on normal days too.

I will try to post pictures once the welding is finished.

Tom Vaught.

[Joel Koontz]

Tom, that is an interesting project. Please do post photos when you can.

I have heard of people running the water through the exhaust crossover similar to what you have described, but I always assumed it would have limited benefit to cold start operation as it takes a substantial amount of time for the water(and therefore the intake) to warm up.

Adding block heater/s to the equation should make it a lot more effective at improving cold start operation.

[b-man]

[Tom Vaught]

Thanks B-man, for the idea on the Heat collector formed around the head.
Is that a basic RA-IV deal or more common?

Tom Vaught

Don't have a heater (Heater Delete) so can't send some of the head heat thru the cross-over and then on to the heater.

[b-man]

Originally Posted by Tom Vaught

Thanks B-man, for the idea on the Heat collector formed around the head.
Is that a basic RA-IV deal or more common?

Tom Vaught

Don't have a heater (Heater Delete) so can't send some of the head heat thru the cross-over and then on to the heater.

Made it from a common 4X-head '73 -'74 heat collector, spent a bit of time reshaping and trimming it. Meant to be attached to a couple of small #10 studs welded on the head bolts.

[Overkillphil]

Originally Posted by Cliff R

The -28 degree test also prompted me to do an oil change, as it was pegging out the 80psi gauge for a couple of minutes till the oil heated up some. I dropped the 15W-40 and put in some 10W-30, not wanting to blow up the filter or shear the pump shaft testing this stuff in these extremes. On the second test this morning oil pressure was down to 77psi for the first few minutes, which made me a bit more comfortable during the testing.

This is my biggest concern with the polymer distributor gears.

B-man, that's a great (and simple) solution and I'm noting it as an option for my Kauffman heads.

[elefantrider]

B-man, is the crossover welded shut in the head or intake?

Nice hardware, I have ran the two those rear heater exits joined together for years, just two stock heater nipples and a plastic t-pipe. Supposed to even out the cylinder temps.

[Joel Koontz]

B-Man, thanks for the photos. That water hose arrangement is something I can do without much cost/effort. My Tri-Power Intake is already modified(water crossover separated/ground for HEI clearance) so I am not concerned about making a few additional mods to it.

Elefantrider, he has Eheads which(depending on which Eheads) either do not have any openings for an Exhaust Crossover, or small holes in the heads which can be sealed with pipe plugs. I assume(B-man please confirm) the stock intake gasket creates the seal between the Head and Exhaust Crossover in the Intake.

[b-man]

The heads are 72cc Edelbrock with no exhaust crossover passage, so yes the intake gasket seals off any water flowing into the crossover under the carb.

Unfortunately I never got the chance to run this setup, sold most all the major parts shown here when I went another direction with the engine for the car.