GraniteGuy88 Posted February 6, 2021 Share Posted February 6, 2021 Well guys I finally bought a new carb. The old one was a 650cfm. Alot of you guys suggested a 750 or up. Im just a cruiser. I ended up getting a 670cfm Holly. Its gotta be better I am horrible at adjustments and fairly new to Big engines. Once everything was put on it came factory set to 1200rpm idle. Finally got the idle to around 700-800rpm. It runs decent but seems like it lacks a little when driving. Still have a rolling vibration under car anything 45+. Also before the new carb my temp hung around 160-180F. Now its getting up around 200-210. Just bought a new thermostat Im about to put on. Whats average running temp on a 454. Pretty sure its mostly stock except headers,intake and carb. Also special thx to a few of you guys who have really helped throughout the process of getting it running decent. Did rocker arm adjustments while running. Loosen til tic, quiet tick +1/4turn. Now im noticing when it heats up i can hear a couple arms ticking. So ill be trying to quiet those down tomorrow also. Just a update. Thx guys. William 1 Quote Link to comment Share on other sites More sharing options...
MC1of80 Posted February 6, 2021 Share Posted February 6, 2021 I understand the reasons for the smaller carb. Still avenger series holley. The lacking department is most likely due to the fact that big block chevys came from the factory with 750-800 cfm carbs. Add intake , headers and the such, the 670 is too small. You may be able to make it better, ie jets, squirter/s but I feel you still will not be happy with the overall performance of the engine. What viscosity oil are you running? Tapping when hot and not cold could be the oil being too thin. Is the electric fan still working? Believe it or not, the carb could be making it run hotter if the carb is running lean. Pop the old one back on and watch the temp. You already know the old carb was messed with. Most likely to try and make it act bigger cfm than to was. Or, old school trick- with the car running at night, go to a dark place, as little light as possible (obviously at night) open the hood with the engine still running and see if the headers are glowing reddish or possibly even cherry red. If so, engine needs more fuel. 1 Quote Link to comment Share on other sites More sharing options...
GraniteGuy88 Posted February 6, 2021 Author Share Posted February 6, 2021 The electric fan is still working. Put a 30 fuse instead of the 25 that was in it and havent had a problem since. The car definitely sounds better starting and idling. Reasoning and idea behind the 670 was to get a proper working carb. Its weird to me the new bigger cfi carb feels like it has less "balls" to say. I Didnt expect it to melt tires or anything but i did expect atleast the same umph as the silicone mess of a carb that was on it. Maybe just needs tuned? Just went to replace thermostat and there wasnt one in it. I put a new one in it with new gasket. Also straitened out a kink in the like 4" water line connecting the waterpump and intake. I bought the stuff for a oil change. No one could tell me at the parts stores exactly how many quarts or specific type. After google I ended up with 10w-30 6 quarts and 1 quart of Lucas stabilizer. Plan on doing the oil tomorrow if that sounds right also connecting my oil pressure gauge since it says the port is above the oil filter. The oil in it now seemed really thin when i adjusted the rockers. Little dirty also. Quote Link to comment Share on other sites More sharing options...
Dtret Posted February 6, 2021 Share Posted February 6, 2021 I believe oil capacity is 5 qts. Your adding up to 7. Too much oil and you’ll be blowing out seals and have other issues. I don’t know if it’s a factory oil pan or not just be careful and don’t dump everything in Quote Link to comment Share on other sites More sharing options...
MC1of80 Posted February 6, 2021 Share Posted February 6, 2021 Factory oil pans are 5qt and one in the filter for a total of 6qts. 10w30 in my opinion is too thin for an old school engine. The tolerances are not as right as the new cars. I recommend Rotella 10 40. It's diesel oil but cleans and has a high zinc content for the cam and lifters and it doesn't hurt the wallet too bad. What temp thermostat did you install? I like the 160 some like 180. It's up to the owners preference and climate the car is used. Did you adjust the air mixture screws? Check the float level? Timing? It may be a little low. Great progress you are making! Quote Link to comment Share on other sites More sharing options...
GraniteGuy88 Posted February 6, 2021 Author Share Posted February 6, 2021 I adjusted the floats. They were factory 70% filling sight glasses. Now they both sit about 47%. Turned down factory idle buy set screw under electric choke. Then by idle screw near throttle Also adjusted choke. Didnt touch the ratio screws. Its a 180' thermostat. I havent did much with timing. Quote Link to comment Share on other sites More sharing options...
MC1of80 Posted February 6, 2021 Share Posted February 6, 2021 When you get a chance, play with the timing. Advance it a little. See how she reacts. Quote Link to comment Share on other sites More sharing options...
GraniteGuy88 Posted February 6, 2021 Author Share Posted February 6, 2021 Never really messed with timing. Extent of my timing experience is loosening the distributer and slightly turning. That was in a 79 351 and a 69 slant 6. Same principal apply?Never messed with actual timing chains n such. Ive heard horror stories about peoples timing belts\chains. You think the head rattle could be timing related. Use to have diesel sounding knock/rattle coming from passenger rear head. I tuned the rocker bolts. Passenger side sounds way better but driver rear now does it worse. Its not so much on acceleration. More of idle. speed\neutral\decelerating it clacks. Once it heats up you can hear it pretty good sitting still in drive. Pics of when doing it last time. Quote Link to comment Share on other sites More sharing options...
MC1of80 Posted February 6, 2021 Share Posted February 6, 2021 Yes, same principal. The vacuum can on the distributor turned towards the carb is advancing the timing and towards the firewall is retarding. You want to advance. Change the oil to a thicker oil with zinc and then see how the valves sound. Quote Link to comment Share on other sites More sharing options...
GraniteGuy88 Posted February 7, 2021 Author Share Posted February 7, 2021 Its a good day guys. Changed the oil to rotella 10-40. All the clacks knocks and rattles went completely away. It had really runny oil in it. Also found out why the new carb didnt feel right. The throttle cable assembly was too far forward not letting the pedal give the throttle full gas. What a couple knuckle head mistakes. Also MC1of80 should get a kick out of this.... The fan you had repeatedly said I should remove before loosing a finger.. In the middle of reading the instructions about tuning the choke I fired it up and watched the paperwork get sucked into the fan and obliterated. I laughed my [censored] off. Tightened a few of the bellhousing bolts. Got rid of the rolling vibrations over 40. Temperature hangs around 220-230ish. 205-215 cruising. Took about 5.5 quarts to get good on the stick. Quote Link to comment Share on other sites More sharing options...
MC1of80 Posted February 7, 2021 Share Posted February 7, 2021 Glad you are making progress and what was advised is working out. You were warned by myself and others about that fan!!! Git er gone!!!! Just glad it wasn't you fingers or someone else's. Quote Link to comment Share on other sites More sharing options...
Dtret Posted February 7, 2021 Share Posted February 7, 2021 You could eliminate the electric fan and get the proper shroud. That in itself could be part of the overheat problem and will take care of the electrical fuse problem. Just sayin. 2 Quote Link to comment Share on other sites More sharing options...
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