Engine upgrade stalled
Thread Starter
Racer
Joined: Aug 2019
Posts: 253
Likes: 24
From: Oklahoma
Engine upgrade stalled
I recently upgraded my 79 L82 which was running and driving fine before I did my upgrades. I installed a set of estreet heads a set of long tube headers and a stall converter. I already had a stage 3 cam in the car . Herein is the reason for my questions. After adjusting the valves and setting #1 cylinder at tdc on the compression stroke and assuring the rotor was pointed at #1 cylinder I attempted to start the engine. A very large backfire occurred making me believe I was 18o deg out but I was not. Could someone share some possibilities please. Thanks
Le Mans Master
Joined: Apr 2001
Posts: 5,941
Likes: 281
From: Was New Orleans but swam to Baton Rouge LA
Cruise-In IX Veteran
Stage 3 cam really means nothing to me. Everyone has their own version. Is this a solid flat tappet cam or a hydraulic? What did you set the valves to cold lash, hot lash, zero lash? How did you find TDC? Did you make sure that plug wire #1 is where it needs to be on the cap?
Thread Starter
Racer
Joined: Aug 2019
Posts: 253
Likes: 24
From: Oklahoma
Burning Brakes
Joined: Feb 2022
Posts: 988
Likes: 183
From: South Carolina
I’m in the same process,trying to get everything wired and hooked up,so,maybe a week or two at the most,before I try to crank it,I have my headers on the engine,and will have to take it to a muffler shop to have them welded,and it’s about a foot off the ground now,but hey are about 2-3 inches below my existing pipe,and actually a inch or so below the pan,what kind of ground clearance do you have,oh,I have a 1981.and I replaced e street heads,Edelbrock intake,AVS2 carburetor,and HEI distributor,and headers. Thanks
Thread Starter
Racer
Joined: Aug 2019
Posts: 253
Likes: 24
From: Oklahoma
I’m in the same process,trying to get everything wired and hooked up,so,maybe a week or two at the most,before I try to crank it,I have my headers on the engine,and will have to take it to a muffler shop to have them welded,and it’s about a foot off the ground now,but hey are about 2-3 inches below my existing pipe,and actually a inch or so below the pan,what kind of ground clearance do you have,oh,I have a 1981.and I replaced e street heads,Edelbrock intake,AVS2 carburetor,and HEI distributor,and headers. Thanks
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Burning Brakes
Joined: Jan 2003
Posts: 961
Likes: 275
From: Frederick MD
That is engine specific. If your static compression is up around 10:1 I would say its advisable but there is some much else that factors in. Timing, combustion chamber shape, AF ratio, camshaft parameters etc.
Le Mans Master
Joined: May 2007
Posts: 5,028
Likes: 1,120
From: North tonawanda NY
That completely depends on you compression ratio and what it is with your new heads? if they were 64cc chamber heads theres a good chance you may need at least 89 octane but it depends on other things like the quench and chamber design. and your dynamic compression ratio which is determined by the cam which can either increase or bleed off some compression. there are calculators online to help determine this stuff, thats how I did it for my build.
Le Mans Master
Joined: May 2007
Posts: 5,028
Likes: 1,120
From: North tonawanda NY
I now your kidding but in case your not, keep in mind the bigger tires will be like going to weaker diff gears, the car will likely deliver less power to the ground than it did before the upgrades then. a couple inch difference it tire size makes a big difference in gear ratio.
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
What did you end up with for a cam? That will probably have the largest impact in your case as far as engine specs. Any Idea what the quench ended up being?
Having a higher stall converter will help. What is the rear gear ratio? Cooling system performance will make a big difference too.
Get the timing set up right and the carburation dialed in will make a huge difference in dirveability as well. Use Lars" papers to get this right. Having Lars rebuild your carb would be nice performance upgrade, unless you want to tackle it yourself. Then I suggest using Cliff Ruggles book on the subject. you'd be amazed at the difference a properly dialed in carb can make.
There are a lot of factors involved in what octane to use. If you just want to be safe use the highest available at the pump.
Having a higher stall converter will help. What is the rear gear ratio? Cooling system performance will make a big difference too.
Get the timing set up right and the carburation dialed in will make a huge difference in dirveability as well. Use Lars" papers to get this right. Having Lars rebuild your carb would be nice performance upgrade, unless you want to tackle it yourself. Then I suggest using Cliff Ruggles book on the subject. you'd be amazed at the difference a properly dialed in carb can make.
There are a lot of factors involved in what octane to use. If you just want to be safe use the highest available at the pump.
Race Director
Joined: Jul 2015
Posts: 13,082
Likes: 3,399
From: SW Florida.
steve. OP. what do you have for ground clearance? and for comparison's sake, fender lip to ground at the center of the tire Golferdad. if you can't find a number on those headers to tell what they are for, sell them to anybody that has a small block in anything else. these cars hit the ground enough already.