Building a 455
#121
Whats the timing doing at break in RPMs. For the break in stand I like using a big electric fan from like a 2007 ford fusion which is what I got and i use a moroso electric water pump drive. Just fwiw
#122
so i got rid of the radiator altogether and piped water in the bottom hose and out the top hose continuous flow through, which finally kept it cool enough to run for about 25 minutes.At 2100 rpms the timing was at about 20 btdc with the vac advance hooked up. i should be good with break-in so i drained the oil and will change it tomorrow.For one i think that radiator is shitty and not adequate to keep this motor cool and the 190 thermostat could be suspect ? i have a new water pump on there but they make much better aftermarket water pumps that may be in my future.all the fine tuing stuff ill wait until the motor is in the car.
#123
Get the biggest 2 core with 1"+ tubes rad you can fit, 160 or 180 Robert Shaw and a Flowkooler water pump. It looks like you the big crank pulleys from A/C cars, also good. I had many issues cooling the 403 in my 88 Cutlass.
Last edited by olds 307 and 403; January 27th, 2019 at 11:35 AM.
#125
Did these upgrades solve your problems with the 403? Most of it can be had at summit racing for a reasonable price .thanks again
#126
Not sure if you guys read my other post but as I started digging into this it’s been determined that my piston to wall clearance is only about half of what it should be.Likely one of the causes of overheating , and probly won’t live long. I’m done dumping money into this . So I’m gonna take some time to figure out my next move. Thanks for all the help . Stay tuned
#127
Not sure if you guys read my other post but as I started digging into this it’s been determined that my piston to wall clearance is only about half of what it should be.Likely one of the causes of overheating , and probly won’t live long. I’m done dumping money into this . So I’m gonna take some time to figure out my next move. Thanks for all the help . Stay tuned
#129
Yes, I ended up with a Champion 3 core, it was barely enough 195 to 215 with a 160 thermostat. I had a large 2 core, it ran around 185 but eventually leaked between the cores, currently filled a ton of sealer, now runs warm with a 260. Between bad thermostat's and under drive pulleys, all caused many headaches. Get either a large two core or a 4 core rad.
#130
Not sure if you guys read my other post but as I started digging into this it’s been determined that my piston to wall clearance is only about half of what it should be.Likely one of the causes of overheating , and probly won’t live long. I’m done dumping money into this . So I’m gonna take some time to figure out my next move. Thanks for all the help . Stay tuned
Its possible to lap it out but that size a bore will take a bit of time and a few rolls of emery paper.
#131
theres a good chance i went into panic mode with this engine .after hooking up a 4 core aluminum radiator from summit and installing a quality thermostat, along with a carb switch (quadrajet was way too lean )ive been able to run this thing on the stand several times with temp in the 190 range .Got the timing set pretty good for now and getting 18inches of vacuum.I had an avanti modified holley hf650 on the shelf that is working very well for now ,but will go back to a quadrajet once its in the car.getting back to the piston to wall clearance these coated skirt power forged pistons are designed for tighter clearances as per the factory rep so im not going to worry about it too much.I forgot how stressful it is to enjoy a hobby. as always thanks to everyone
#133
so ive been sidetracked on my little 80 firenza but finally decided to sell it to continue forward with this project .we've run the engine multiple times on the run stand now with no overheating issues .it sounds and runs great! no luck selling the 307 that is coming out of the 80 cutlass .so it will be properly prepped and stored for now .in the coming weeks im going to drop the 455 in .still torn on the whole header vs manifold thing but will figure that out .i will put an end to this build thread and maybe start a new one on the 1980 cutlass supreme i have a long way to go before running and driving and im sure many more questions and welcome advice.thanks for following along and i will keep things updated as i progress.
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