pressurizing coolant passages on block? And general ?

[fftoddster]

Ok my 21 stud engine is out of the car. (had some unfortunate clutch/trans input shaft issue with swap as well as a welch plug leak and front seal and rear engine oil pan leak.

My goal is to get the car back on the road without doing a full restoration and spending a bucket load of $$$

Car had sit for 30 years before I acquired it. Got the engine running and seamed to run pretty good. Smoked at first but cleared up after running it for awhile. Could not test drive it because trans was shot.

SO...
Engine is out. Oil pan off. Radiator hoses are attached to block and water pumps and plugged with pvc fittings. Filled cooling system passages up with water and left sit. It is holding water. Car came from Minnesota so I was concerned about potential cracked block.

Would pressurizing system by either garden hose (about 80-100 psi) or compressed air (what pressure?) be beneficial in trying to making sure no cracks in block before I clean it up and put back in the car?

Engine is a '37 21 stud, odometer shows 62,000 mi. 3 speed Trans had been replaced somewhere down the line (serial #s did not match)
Guessing engine has probably been rebuilt at some point (paint overspray on distributor coil...

Compression test all cyl between 80-85psi Eng not very warm and forgot to open throttle.

Oil pressure about 50psi

Do not really want to take heads off... and look for problems as my intentions are just to get it back on road without complete overhaul and breaking the bank.

My plan is to replace all welch plugs and clean out the passages. New water pumps? (old ones do not appear to be leaking now, but thought they were when in the car.) Clean up Exterior of eng. Replace oil pan gaskets, fresh plugs wires ... and put back in car. backed up by a T5 trans and 4:11 gears.
New dropped front and rear suspension and hyd brakes.


Thoughts???
Remember I am NOT looking to spend $4000 + on engine build especially when it appears to run pretty good.

 

[JSeery]

80-100 psi is too much pressure. Pressure test are normally preformed at much lower pressures. I would use something in the 10 to 20 psi range (although there are recent post on the Barn of using 50 psi).

 

[V8COOPMAN]

JSeery is correct! Think about water pressures in a MODERN, high-pressure automotive system and they only use a 14-15 PSI radiator cap. I AM NOT SUGGESTING THAT YOU USE A HIGH-PRESSURE RADIATOR CAP on YOUR system....I'm only trying to let you realize MORE-realistic testing pressures. DD

 

[fftoddster]

I totally get that the pressures would be way to high for the radiator. The radiator is not part of the equation.

I was just thinking that when you shut off the nozzle on your garden hose the residual pressure is not too much for the hose or the fittings so it should not be too much for the block and heads. BUT I will stick with air pressure on top of the water inside the block and dial it down to 10-15 psi to be safe.

OR is the fact that the static water level has not dropped and run out of the block enough evidence?

 

[jack orchard]

If you are going to use a T5 transmission (especially an S10 T5), 4.11 rear gear might be a bit too low. I think first gear is 4.03. Maybe a 3.7 or even a 3.5 gear might make a more enjoyable ride while rowing through the gears. Just a thought.,...jack

 

[flatheadmurre]

I think you will need to block of the pumps before starting to raise the pressure a lot...
And if it hasnt taken any water had heating issues and are running good i´d be really tempted to stick it back and just run.

 

[fftoddster]

Thinking it is a similar test as this (although not as good and thorough, but able to do with engine still together.

I figure if I get any water leaks or the pressure drops and does not hold then I would know I have an issue?

How much pressure do they apply when using a tester like this?

 

[fftoddster]

I think you will need to block of the pumps before starting to raise the pressure a lot...
And if it hasnt taken any water had heating issues and are running good i´d be really tempted to stick it back and just run.

Well it had water leak from welch plug, radiator and I thought water pumps although the water is not leaking from the pumps now.

Still thinking it may be good insurance to replace/rebuild them.

 

[fftoddster]

If you are going to use a T5 transmission (especially an S10 T5), 4.11 rear gear might be a bit too low. I think first gear is 4.03. Maybe a 3.7 or even a 3.5 gear might make a more enjoyable ride while rowing through the gears. Just a thought.,...jack

I also have 3:50 gears but the 4:11 are what's in the rear now.
I understand I may have to shift from 1st to 2nd pretty quick (that's how my VW bug is and does not bother me) but thinking with the stock old 21 stud engine that it will give me a little more power running around on the street. Also give me a little better rpm range at fwy speeds.

Once using it if it does not work out well I can drop the 3:50 gears in.

 

[sidevalve8ba]

If the T5 is from an S-10 and you have 4.11 rear gears you won't even use 1st gear. Second gear starts will be the norm. First gear in an S-10 T5 is either 4.03 or 3.76 and that coupled with the 4.11's would be very low gearing indeed.

 

[fftoddster]

If the T5 is from an S-10 and you have 4.11 rear gears you won't even use 1st gear. Second gear starts will be the norm. First gear in an S-10 T5 is either 4.03 or 3.76 and that coupled with the 4.11's would be very low gearing indeed.

If I run a 700-16 rear tire (30") and 4.11 gears behind my T5 with .72OD and stock 21 stud flathead the chart shows at 70mph I would be at 2306RPM /650-16 tire at 2384RPM

I forget what the numbers are with the 3:50 gears but at fwy speeds the rpm would be so low I don't think the engine would produce enough power and I would have to down shift at every hill or if the wind blew.

So maybe I will be starting off in 2nd gear?
At any rate I will run it and see how the gearing works out and can swap it if need be.

 

[FlatheadTed]

A good running flat head has tons of power ,you cannot compare it to a VW ,go to the gear box guy Van pealt and get the gears to repair the current box ,save all that cutting etc 60.000 miles you have a piece of history there ,Like Flat Mure just run it .Ted

 

[JSeery]

I'm not a fan of the S10 T5s gears myself, but you can change the gears out. I like the mustang T5Z gearing (2.95/1.94/1.34/1.00/0.63) with a 4:11 rear end.

 

[Karl Wolf]

Thinking it is a similar test as this (although not as good and thorough, but able to do with engine still together.

I figure if I get any water leaks or the pressure drops and does not hold then I would know I have an issue?

How much pressure do they apply when using a tester like this?

I have done this a LOT.
When using the Irontite brand pressure test bench/jig, I would try to get the set up to hold 30lb. air pressure. This should be enough to find leaks.

With a home made pressure test plate, I find it easily holds to 50/75 lbs. I start at 30 lb., and look for leaks with a spray bottle- water and a little soap.
To finish, I raise the pressure and look around again.

There is a lot more combustion pressure in a running engine than there is doing a pressure test.

Not all cracks leak. I have a 85hp block I drove around town a few miles, no water loss... When I pulled the heads, it had three cylinders with huge cracks, intake seat down into the bore. You need to magnaflux test also.

Karl

 

[JSeery]

There is a lot more combustion pressure in a running engine than there is doing a pressure test.
Karl

Not disagreeing, but there is a lot of difference between combustion chambers and water passages! When you are pressure testing a block you are not pressurizing the combustion chambers, you are pressurizing all of the water passages including large surface areas along the side of the block. Pressure is given in Pounds per Square inch, so need to keep in mind that the total pressure on the large surface can become quite large.

Funny story, worked as a Hawk Missile technician in the military. The missiles are stored in large cylinder type containers and purged with nitrogen at seems like 20 or 30 psi if I remember correctly. You are not to remove the end caps until the pressure is released down to zero. But in typical faction we would start removing the bolts on the end caps while the system pressure bleed down. We would start with ever other one and then go back and slowly loosen the remaining bolts a turn or two at a time. Well one day got a little ahead of the bleed down and it blow the cover off the end and out about a 100 feet. The pressure was around the 15 psi range I believe, learned a lesson about psi and surface area! (also the volume of the pressure behind it)

 

[fftoddster]

A good running flat head has tons of power ,you cannot compare it to a VW ,go to the gear box guy Van pealt and get the gears to repair the current box ,save all that cutting etc 60.000 miles you have a piece of history there ,Like Flat Mure just run it .Ted

No comparison... apples to oranges but:
s10 trans with 3.97 1st gear and 4:11 final give effective ratio of 16.3167
vw 1st gear 3.8 and ring and pinion of 4.375 give effective ratio of 16.625

So aside from tire size (and of coarse HP) I would think the initial take off from a stop to be similar. In the VW taking off from 1st: by the time I have the clutch released I am already applying it again to shift into 2nd. I would expect this to be the same with the T5 in the Ford with 4:11. That was my comparison. I do believe the 4:11 will give me better more usable RPM's at fwy speeds.

Also the 4cyl S10's came with these 5 speed trans and 4:10 gear ratios and the horsepower is fairly equivalent 92 HP and 130 'lbs of torque.

 

[fftoddster]

Not disagreeing, but there is a lot of difference between combustion chambers and water passages! When you are pressure testing a block you are not pressurizing the combustion chambers, you are pressurizing all of the water passages including large surface areas along the side of the block. Pressure is given in Pounds per Square inch, so need to keep in mind that the total pressure on the large surface can become quite large.

Funny story, worked as a Hawk Missile technician in the military. The missiles are stored in large cylinder type containers and purged with nitrogen at seems like 20 or 30 psi if I remember correctly. You are not to remove the end caps until the pressure is released down to zero. But in typical faction we would start removing the bolts on the end caps while the system pressure bleed down. We would start with ever other one and then go back and slowly loosen the remaining bolts a turn or two at a time. Well one day got a little ahead of the bleed down and it blow the cover off the end and out about a 100 feet. The pressure was around the 15 psi range I believe, learned a lesson about psi and surface area! (also the volume of the pressure behind it)

So this kit is designed to put pressure into the water jacket.
Found this on Speedways site:



The flathead pressure tester is set up for air using 60-80 psi. Spraying soap and water on block will allow visibility of crack or you can submerge block in water tank. Kit comes with instructions

 

[V8COOPMAN]

I'm not a fan of the S10 T5s gears myself, but you can change the gears out. I like the mustang T5Z gearing (2.95/1.94/1.34/1.00/0.63) with a 4:11 rear end.

The 2.95 1st gear gearsets are virtually perfect for these old Fords. The same gearsets were also available in the early NWC Camaro and Mustang T5s with the same 0.63 OD. They worked magnificently at getting those big ol', heavy-enough Camaros and Mustangs comfortably and efficiently away from the stop light........and the starting lines, too. Guys are missing the boat and wasting a lot of time with those wimpy 4.03 and 3.76 gearboxes. To each his own, though.

Just think about this......any of you guys know what the old Ford 3-speed gearbox 1st gear ratio is? Damned sure wasn't anywhere near 4.03! 1st ratio is 2.82 on the majority of 3-speeds, which have 28-tooth clusters. DD

 

[JSeery]

To add to what V8coopman posted, there is also the issue of the ratio between the gears. The Ford/Camaro ratios are close ratio gears as opposed to the truck gear spacing in the typical S10s.

 

[fftoddster]

Well it's a shame that nearly all the T5 kits are based on the S10 T5 trans.

You would think That since the Ford box and gears are so much better that there would be much more of a push and kits avail to go that route?

Well I have what I have. From most of the input I have received from here and on the hamb most everybody says it is a huge improvement and makes the flathead that much more fun to drive even with the Low first gear.

I will file away this information if I happen to tackle on yet another project when this one is done. I had done the Camaro T5 swap in a '62 Buick Skylark and was happy with the outcome. Hopefully this one does not disappoint.