170 six low compression and temperature problems

[Anonymous]

I have a recently rebuilt 170 six in my 61 ranchero, but it doesn’t
performs well.

1. I measured the compression and it has 90 psi in all six cylinders. I read in this forum about thickness of the head gasket, but I don’t think this could be all the reason of such a low value.
Maybe during the years, and several jobs, the valve seats may be much deeper, causing an increase of the chamber volume. Can anybody help me suggesting a solution? Is it possible to put valve seats in the cast iron head? Will it be enough just to mill the head, lets say a max of 0.090"?

2. I am having heating troubles. I rebuilt the radiator (2 rows like the original one), new thermostat, water pump, valves adjustment, dwell and timing advance (vacuum is working right), every thing seems to be Ok. I am afraid that the rings gap is not correct and this may be the reasson to become so hot. Any sugestion will be appreciated.

Thank you everybody. This forum is excellent. In my country there is no possibility to find information about those cars and your help and all the posts are invaluable for me.

Juan
San José, Costa Rica

 

[Lazy JW]

Jaun,
Welcome to the forum. Sorry to hear of your troubles with the engine. 90 psi compression is pretty low, but the good news is that it is all nice and even. The low compression and the overheating makes me suspect timing issues. Are you absolutely certain that the timing chain/gears are installed correctly? I would verify this before going much further. Late cam timing can cause low compression and overheating. Once this is verified then you can proceed on to the usual things like combustion chamber volume, head gasket thickness, etc. Are you equipped to perform the checkout procedures? You need to either pull the timing cover to look at the timing marks or use a dial indicator and degree wheel to do the check with the engine assembled. I have actually seen engines put together incorrectly, and it will give you fits trying to figure it out.
Joe

 

[addo]

90 is indeed low. Even the low compression 170 I have listed in my manual shows typical pressure hot to be 175 PSI.

In addition to the points Joe has mentioned, it is also possible that someone has installed a later model cylinder head, or used pistons that are more dished, or lower in height compared to original.

Heat is always a problem with early Falcons. Many people choose to install a 3 row radiator, or an aftermarket aluminium unit. You will also find a lot of helpful information in the forum for these, if you use the "search" option.

Regards, Adam.

 

[Anonymous]

Thank you Adam and Joe. For a newbie like me it’s a splendid thing to receive this expert support.
With a timing light I adjusted the advance (5 degrees with out vacuum, and then connecting it I verified the time advance), but I am not sure about the correct installation of the gears.
If possible one of those nights with a screwdriver in spark plug hole I will try to verify that the mark in the crankshaft pulley and in the cover corresponds to TDC in cylinder No. 1. , next on Saturday I will open the front cover and check good marks alignment in the sprockets, also check the chain condition.

Is there any tip on how to loose the crankshaft pulley? In my shop manual, Ford uses some special tool…

When done I will comment to the forum

Juan

 

[addo]

The front combination pulley/ balancer may be removed with a standard puller, made for this type of removal on many cars. It sells around the $10 mark in the US.

I found that the bolts supplied with mine were not long enough, and bought three extra ones of the high strength variety. There are some difficult issues with balancer removal:

First, you need a good strong socket and breaker bar to fit the centre bolt. With a heavy hammer, strike the breaker bar sharply to loosen the bolt. Trying to turn it as normal, will just rotate the motor. It needs this "shock" combined with turning effort to loosen.

Then, do not remove the bolt entirely. Wind it out about 3/16" inch (4-5mm) so that the "pusher" bolt in your balancer puller, can force against it. If you remove the balancer bolt entirely, the pusher bolt will damage your threads inside the crankshaft front. When the balancer has moved out enough to close the 3/16" gap, wind its bolt out the same distance again, and repeat the procedure. After two or three times, it will come loose in your hands.

Regards, Adam.

 

[ruckus68]

i have a New old stock thin metal head gasket that is for a 170 that i would be willing to sell ( i bought it for my 200 but it is too small) 40 plus shipping

It would help increase your CR

let me know

John

 

[Anonymous]

Thanks John. By now I will try to fix the main problem of low CR, far beyond gasket thickness.

Juan

 

[MandarinaRacing]

Juan
San José, Costa Rica

En donde vive????? Que pequeño es el mundo!!!!

Saludos de otro TICO.....

Alex

 

[Anonymous]

Nice to hear about another Ford six fan in the country , actually I live in a small country village, Santa María. Coffee growers and lots of mountains everywhere. I will post a couple of pics of my car soon.

Qué bién!, MandarinaRacing. Gracias por la amable comunicación. Espero tener mi Ranchero 61 caminando y pasando Riteve pronto (tal ves 10 años). Me gustaría conocer tu Mustang y por qué no hacer un piquesito Ja, Ja…