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#1
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Plug heat range
What determines the chosen plug heat range? When my engine was dyno'd it had a 1050 dominator ona victor junior manifold. the dyno controller said that it wasn't doing me any favours but, as it was all I had, he dyno'd it. It made 600 HP and 600 ft lbs. He also advised that i put a colder plug in, which I did.
I have now fitted an adapter and gone to a 850 double pumper. I have only lost 2/10 ET but 6 mph. Is this fuelling? I expected to be slower but not 6mph. Also how do I determine if its still the correct plug? |
#2
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He might have said that because he is used the Chevy's . A Pontiac can run a bigger carb compared to a Chevy of like horsepower.
Long stroke engines like ours have a lot of pull when that piston goes down. Plugs ? http://members.uia.net/pkelley2/sparkplugreading.html |
The Following User Says Thank You to Dragncar For This Useful Post: | ||
#3
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With out a spark plug magnifying flashlight and the knowledge to translate what your seeing you really can not tell what's going on with your plugs heat range, nor your air to fuel ratio.
Due a on line search for the 5 page paper called Spark plug reading 101. This paper is by Mike Canter. There's no such thing as a Victor Jr for a Pontiac so are you posting about a SBC or some other non Pontiac motor? You gave up 23% of the air flow you had with that 1050 to 850 swap, so I am not surprised that on a 600 hp motor you lost 6 mph from your ET. Hook up a vacuum gauge that you can read during a run to the motor. If then on a run you see 3/4" hg or higher showing up within 500 rpm of your shift point then that's telling you your 850 is too small. The bottom line is this. At peak Rev's if you get anything higher then a zero vacuum reading ,then YES at that point and ONLY then are your forcing the descending Pistons to try and make the added effort to suck air in and that's what you do not want in terms of producing the highest amount of peak Hp. This once again this is in terms of and purely relating to peak hp and a slight vacuum reading can make for better torque production within your builds intended power band.
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Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! Last edited by steve25; 10-03-2023 at 06:17 AM. |
#4
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there's some great videos on youtube regarding plug readings and all
steve morris made a really great one, and funny too i was told one way to check, is to run various ranges at once, make your run, power off, then check, the fella from 4secondsflat will give you some great advice. he said stick ar3222, 23, 24's in (or something along those lines, been a real time since i had that chat with him) i've never done that, but maybe when i decide to get the tinker bug again |
#5
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Thanks for the replys. Sorry steve25 but I was certain that was what I bought. Its a high rise single plain that was for fuel injection but i made plugs and filled the injector holes!!!!
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#6
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If you dyno it with a 1050, and he said you needed a colder plug, then went with colder plug then change to a 850. You probably dropped a good 30 hp and now that colder plug may need a hotter plug. Because it changes the air to fuel ratio. Only way to really tell is to make a run, shut it off and pull plugs and see what they look like. If you can take a picture of the plug I can tell you right away if it to cold can also tell if its got enough timing. I’m curious why did you take the 1050 off and put 850 on.
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#7
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Running on dyno then at track can use different tuning
I personally have picked up et switching from 850 to 1050.you need to make a full bore run and look at plugs
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pure pontiacpowerd 86 grand am 455 eheads solid flat tappet cam 8;95 @152 HOFFMAN RACING |
#8
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Exactly
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#9
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A lot of racers like a 4150 carb vs a 4500 for bracket racing. More consistent some of them say and the people work worked over my 1050 told me the same thing. You will make more power with a 1050 if tyou have a big enough engine and it needs it.
I never won a thing while I had the original 1050 on the car. Many, many trophies with my 850. 850s actually flow just over 1000cfm. I am looking into buying a all billet 1100+ cfm 4150 carb. I just put my 850 back on my fresh 461 High Port engine today. |
#10
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The Dyno tells the story, if you want to slow car down Because you’re only bracket racing. Then why did you spent all that extra money trying to make as much power as possible with your combination. LOL
After second pull, Larry says your 1050 isn’t going to cut it, two days later bolted on a Pro System 1150, first pull it pick up 35 hp. Think I should go to a 850. LOL Consistency winds bracket races. Not dropping hp..LOL |
#11
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Please lets not get all stressy. I changed the carb as I regularly use the car on the street. I live in a very rural part of the UK where the roads are ,in some cases, no better than farm tracks. The car was a beast on the road with the dominator on with very little transition between idle and flat out but loved it on the track. Its a fine line doing both street and strip as many of you know. going from the dominator to the 4150 wasn't simple ether, all I could find was an adaptor to go the opposite way to what I needed, therefore had to alter the way the adaptor fitted which meant changing the throttle linkage quite a bit. The dominator was also borrowed from a friend that said I could have it as long as I needed it but, he wanted it back when I started running as quick as him!!!!
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The Following User Says Thank You to wakesupremo For This Useful Post: | ||
#12
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Quote:
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#13
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Quote:
4150 carbs react better, just the way it is. Bracket racing is all about the reaction time. Air is moving faster though a 850 at starting line RPM than a 1050. I can bolt on the 1050 and see how fast it goes but its not going to get a steady diet of it. I will not be able to make enough HP to put the block at risk with the 850. There is a good reason for running it, most of the time. The HOs are going back on this block and I do not want anything to happen to it. Your situation does not compare to mine or the OPs. A 505 with a great big set of heads and a highly ported Victor is apples to oranges with a stock block. I bet you did pick up 35 HP. I might pick up 10-12 HP and its a heavy car so I might not even see it at the track. Just on a dyno. BTW, the actual cfm of a 1050 is 1130cfm. Plenty for a 6500 RPM 461. It is the Street Section after all. |
#14
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Quote:
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#15
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Quote:
If Mike wants to copy my build (doubt it) you are the last person to ask. You might suggest your super Comp cam that puts stock blocks at risk. I paid to have that fixed BTW. No High Port head starts out at 87 ccs, you are thinking E heads. They are 80 cc heads that only need to get cut .030 to get me down to 74 cc. I was at 10.8-1 CR, now I am at 11.5-1 CR. You want to know how to go from a 4500 intake to a 4150 all in only one inch ? Here it is and if you have any skill, a drill press and a jig saw you can make your own. All you need is 2 pieces of 1/2" aluminum flat bar stock and get to work. In life we can actually do something or be a dyno queenie who makes pulls and passes they do not want to prove. BTW, I thought you had me on "ignore". Probably for the best. Any good bracket racer knows a smaller carb is more consistent than a larger max power carb. Smaller carbs recover better and react quicker off the line. They are making all billet 4150 carbs that flow as much as a 1050 these days. If you buy a Pro Systems Holley carb you are getting a main body and base plate Made in China. They have been for years. These billets are 100% Made in the USA. Just ordered one and its going to be sweet. Boosters are lower than a Holley and get a better signal. Last edited by Dragncar; 10-05-2023 at 01:59 AM. |
#16
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How i done it was to buy an adaptor that goes the other way, 4150 base to 4500 carb and turned it upside down. I had to drill out the 'bottom' holes as they were threaded for the carb then thread the 'top' holes that should have been for the manifold studs.
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#17
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The 1" adapter I made works very well with a 4 hole Super Sucker on top of it for 2" total of spacers. My Warrior needed more plenum anyway.
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#18
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I figured that’s what you did you took one of these
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#19
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You are blocked but if someone copies your post in a reply for some reason I can still see them. LOL Mike runs that Comp Cam with lifter bore Brace. In his stock block…for last two years..LOL. It’s actually 195-200. No issues. Which is exactly what you said you were going to do. But then for some reason you got paranoid. He was hoping to learn something from your pump gas stroker motor build, 700 plus hp. Because he never got that out of his combo he thought he could learn something from you. He just don’t understand why now all of a sudden you’re going backwards. LOL spent all that money on that dominator to turn around and run 850. He was anxious to see how much you’d pick up because he doesn’t run all that stuff, back cut rings, vacuum pump, crank trigger, 2” tube headers and Merge collector, or a pan with a double scraper. Or a super modified oil pump. His only problem is you’re not gonna back up your claims most power pump gas stroker motor. So yeah he’s very disappointed. So I can see as usual my post went right over your head. I thought the purpose of the board was to learn and get help from each other. After following your 3 year build he’s very disappointed. He kept telling me Gach your wrong you should listen to Dragncar. LOL
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#20
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I tried to tell him everything I’ve learned was from Dragncar. Now he’s upset.
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