70/71/72 402
- Thread starter Tim
- Start date
Greg Reimer
Well Known Member
Wonder what would happen if a person put an original, assembled core motor on an engine stand, blocked off the water pump openings at the front of the block, removed the thermostat housing and the stat and slowly poured in about a gallon of un cut swimming pool acid, carefully adding water until you could see it in the bottom of the thermostat passage and left it for a day or two, then very carefully draining it into a large bucket for disposal. It would be necessary to flush the engine out with a hose before disassembly, but I wonder what all would come out and how clean would it be? Just be careful handling everything afterward. Probably would sizzle and bubble a bit until the chemical reaction was complete. Might smell a bit in the process.
wristpin
Well Known Member
Muriatic acid. Youd gett better results having it recirculating at a diluted ration.
Been off the radar for a bit. Work is stupid busy and takes a lot of my time. It’s a good problem being in sales and the time equals reward!
Here’s a quick update on what I’ve done with the 454 blocks,
The marine one I sold because of all the junk in it. The guy I sold it to was going to put it back in a boat because he had one cracked from freezing
Found another one and bought it except it came out of a motor home. It’s a 5445 block from 89 and has 4 bolt mains, peanut port Heads
This I sent to Armstrong’s to get bored and decked to fit the wiesco pistons
Bought a set of 781 heads for it and they are getting 225/188 valves, springs and guides to match the cam
All still in progress
because I can’t leave well enough alone I found a 86 motor home and it was Free!!! After checking it had a 454 with a TH400 trans and all I had to do was haul it out of their front yard! Done! Got the motor and trans out turns out it had a 5445 block but 2 bolt mains
? 236 peanut port heads.
not sure what I’ll do with this one yet but I think the plan eventually is to take the 380W in the 66 and put it in the 62 Pontiac I bought from Don and the 454 current build in the 66. I also have a 51 5 window 3100 pick up I’m getting from a family member that the second 454 would be good in.
Update complete!
Whad I miss?
Here’s a quick update on what I’ve done with the 454 blocks,
The marine one I sold because of all the junk in it. The guy I sold it to was going to put it back in a boat because he had one cracked from freezing
Found another one and bought it except it came out of a motor home. It’s a 5445 block from 89 and has 4 bolt mains, peanut port Heads
This I sent to Armstrong’s to get bored and decked to fit the wiesco pistons
Bought a set of 781 heads for it and they are getting 225/188 valves, springs and guides to match the cam
All still in progress
because I can’t leave well enough alone I found a 86 motor home and it was Free!!! After checking it had a 454 with a TH400 trans and all I had to do was haul it out of their front yard! Done! Got the motor and trans out turns out it had a 5445 block but 2 bolt mains
? 236 peanut port heads.not sure what I’ll do with this one yet but I think the plan eventually is to take the 380W in the 66 and put it in the 62 Pontiac I bought from Don and the 454 current build in the 66. I also have a 51 5 window 3100 pick up I’m getting from a family member that the second 454 would be good in.
Update complete!
Whad I miss?
Attachments
Finished tearing down the second engine. First and second are 5445 blocks both from Motor homes. First has 360 heads, 4 bolt main, 1989 date second has 236 heads,2 bolt main,1986 date. Valves are all the same size, 1.72/2.06, but chambers are different. 236 heads are 1.19 deep 360 heads are 1.25 deep measured in the same place. Exhaust ports are bigger on the 236 than the 360. 236 heads have dual springs and 360 have single.
having said all that Tooth which head do you think is the better torque head? Thinking the latter 360 was changed for emissions. 236 1974-1987. 360 1987-1990
First pic 360. Second pic 236
having said all that Tooth which head do you think is the better torque head? Thinking the latter 360 was changed for emissions. 236 1974-1987. 360 1987-1990
First pic 360. Second pic 236
Attachments
1409236086-88oval OPEN454 Truck
33678173-85oval OPEN454, 118cc chamber, 256/114cc ports
34623675-87oval OPEN454, 120cc chamber, 225/116cc ports
33678173-85oval OPEN454, 118cc chamber, 256/114cc ports
Tim here is a comparison and I cannot find any numbers on the 360 heads either. The 781 is used on a lot of 496 motors. The intake runners are 31cc bigger than the 236. They also have a 113 combustion chamber. Since they are peanut ports they will automatically give you more low-end torque and more throttle response from idol. Not much good above 5000 RPM with any cam. If you’re going to put a small lumpish lump choppy idol The 236 will work fine. Not sure about the 360 due to the lack of numbers. I’m sure they’re fairly similar.
33678173-85oval OPEN454, 118cc chamber, 256/114cc ports
34623675-87oval OPEN454, 120cc chamber, 225/116cc ports
33678173-85oval OPEN454, 118cc chamber, 256/114cc ports
Tim here is a comparison and I cannot find any numbers on the 360 heads either. The 781 is used on a lot of 496 motors. The intake runners are 31cc bigger than the 236. They also have a 113 combustion chamber. Since they are peanut ports they will automatically give you more low-end torque and more throttle response from idol. Not much good above 5000 RPM with any cam. If you’re going to put a small lumpish lump choppy idol The 236 will work fine. Not sure about the 360 due to the lack of numbers. I’m sure they’re fairly similar.
Tooth,
Using the 781’s on the first block, put 225/188 valves in, it’s the spec you and Don J came up with. It will have a 700R4 behind it
I have a set of 236 and a set of 360 for the second block. Going to build a torquer motor. I’m thinking the 236 are the better of the 2 because of the better exhaust opening.it will have a TH400 behind it
Using the 781’s on the first block, put 225/188 valves in, it’s the spec you and Don J came up with. It will have a 700R4 behind it
I have a set of 236 and a set of 360 for the second block. Going to build a torquer motor. I’m thinking the 236 are the better of the 2 because of the better exhaust opening.it will have a TH400 behind it
Seal power makes a hydraulic flat tappet that is an RV cam, it has a rough idle but you can use a stock converter. Last time I bought one it was under $100 for the cam in about $60 for the lifters. It’s in the sealed power book. And it’s a little under .500 lift i’ll see if I can find the number. I had it in my pick up truck that I used to tow my race car. And it would break the tires loose and second gear hauling my trailer. Ask James he was afraid I was going to throw the driveshaft out. I was hauling his country Squire station wagon on my trailer and hit second gear it was bark in the tires. Sounded awesome throttle response was crazy fast.
We were to far away from home to be trying that stuff. 
Got the heads back today, a lot of work done but turned out great!
they were planed .010, stainless valves, 225 intake, 188 exh with new seats, springs per the cam specs with rotater eliminators on the exhaust, (wasn’t any on the intake), runners and bowls were ported by me.
heads are 781
they were planed .010, stainless valves, 225 intake, 188 exh with new seats, springs per the cam specs with rotater eliminators on the exhaust, (wasn’t any on the intake), runners and bowls were ported by me.
heads are 781
Attachments
Nice 