JD 60 compression

[GreenWookie]

Has anyone got any advice on putting compression release valves on a powerblock with 10-1 compression? Was wanting to put them on the sides because of the tight space underneath around the frame. also what type of valve the best, without blowing them out. Any help appreciated.

 

[Anonymous-0]

There is no way to put compression relief valves in a TSC Power-Block. 10:1 compression!!?? That's just a mite high. Any less than about 900 rpm and it will "fall on it's face."

 

[AW Puller]

Slow A says: "There is no way to put compression relief valves in a TSC Power-Block."

Are you sure about that?? Could"a swore I"ve put petcock holes in a power block before...several times.

 

[GreenWookie]

well i know for a fact that you can drill out holes in the bottom... i've seen it done. but i wonder if its ok to put them on the sides of the block, above the plug holes?

 

[Anonymous-0]

Well yes you can put petcock holes in this type of Power-Block, done four myself. If you could open them (which you can't) you will drain antifreeze out of them. Mine even have the "dimpled" area for them and the "cast in part number" on the block. The guy was looking for functional petcocks- mine are not- are yours. If they are, please tell us how you did it. I await your reply. Anyone feel free to reply.

 

[Drew]

Yes, mine ARE functional. You say you have done four blocks. If they dont work, why didnt you stop after the first one?

The trick is to drill right behind the headstud. In a TSC power block, the headstud holes are blind-they do not go into water. Drill an 1/8 or 5/32 hole behind the stud, but still in the stud boss from the bottom thru to the reduced bore part of the block (aprox 1.125 to NO MORE THAN 1.25" from the block deck). Then drill w/ an #R drill from the bottom into the headstud hole, but stop there. Tap w/ a 1/8-27 pipe tap. Screw in petcock. Water doesnt leak.

 

[GreenWookie]

This is all great info thanks. I"m just still wondering what type of valves to screw into the holes so that i"m not blowing them out?

 

[buickanddeere]

It won't fall on it's face. If the carb & timing is properly set and high enough octane fuel used. The 10 to 1 engine will walk all over the otherwise identical 6 to 1 gasser.
Judging by the posts here, there and all over the ytmag site. I'm wondering however if the poster is some dreaming kid that doesn't even own a tractor?

 

[GreenWookie]

Well, thanks buick&deere. I wouldnt say i'm dreaming... just looking for info to put my power block into my old 60 pulling tractor. so i can get it ready for the season. true i've only been pulling for a few years, but thanks for catagorizing me. Thanks for all the info guys.

 

[buickanddeere]

If the power-bloc's stock pistons are used. The compression will not be anywhere near 10 to 1. The factory starter should still crank the engine over. If heavy cables and low resistance conenctions are made. Group 31 battery too with 1000CCA.
If bypass starting is used. The spark will be stronger when system voltage gets draged down while cranking.
Just checking to see if somebody was playing.

 

[Anonymous-0]

BuickandDeere,
By your past post we all know you have never built a JD two-cylinder pulling tractor, and never will. Yes, a 10:1 compression ratio works real well in a buick, but not in a two-cylinder deere. Yes, that 10:1 engine will walk all over a 6:1 engine, until about 900 rpm, when it falls on its face. After YOU have built your own pulling tractor then you can make condescending remarks about kids dreams. A 9.25:1 will have a much broader power band.

 

[Anonymous-0]

Drew,
Why have I built four blocks this way if they don't work!!?? Come on now, you know why, so they look like a JD block. You know how tractor pullers are - we never lie and never ever cheat. Yea, right. So, OK, your method sounds to me like it WILL work. That will teach me to never say never. I would never have thought a relief hole that near the end of stroke would give you enough compression to start the thing. But then again, mine starts just fine at 9-1/4:1 compression and does not "fall on it's face" until about 750 rpm.

 

[buickanddeere]

Slow A is playing games now.
Anybody knows for all the difference between 9.25 vs. 10 to 1. You can easily tweak the 9.25 to 1 to higher compression pressure by changing the valve lash or port cleanup or blueprinting the carb throttle/choke blades etc.
As for an "engine falling on it's face" due to compression. Slow A is showing his adherence to old wives's tales rather than practical experience.
If your high compression engine stumbles. You obviously know nothing about cam timing, port velocity, ignition timing/timing advance.
Slow A is one terrific puller as his pedals his A in the 10-12 yr old class.

 

[gpuller]

Anybody knows for all the difference between 9.25 vs. 10 to 1. You can easily tweak the 9.25 to 1 to higher compression pressure by changing the valve lash or port cleanup or blueprinting the carb throttle/choke blades etc.

It's difficult to tweak compression ratio by adjusting the valve lash, port clean up, or carb mods, since it has nothing to do with figuring actual compression ratio.
Cylinder cranking pressure will be affected by valve timing, cranking pressure can not be used to find compression ratio.

Link to kb-silvolite web page to determine compression ratios
http://kb-silvolite.com/article.php?action=read&A_id=12

 

[buickanddeere]

compression pressure by changing the valve lash or port cleanup or blueprinting the carb throttle/choke blades etc.
[/quote]

gpuller

I said compression pressure, not compression ratio.

b&d

 

[Anonymous-0]

My dear b&d,
Now just what have you been reading - HOW TO HOT ROD YOUR SMALL BLOCK CHEVY? I know all about the 'buzz words' you have been using and I am not impressed. I know exactly what they all mean, how to change them and what happens when I do change them - on a small block chevy AND a two-cylinder JD A/60. The difference between us is I have DONE both and had to live with the results, some good, some not so good. Why do you try to muddle the topic of compression ratios with compression pressure? Two different things - yes, they are related but a different set of problems/enhancements, none of which will CHANGE your compression ratio. Have you ever built a modified engine for any type of competition - I think not. Why wont you accept that other folks have and have learned from the experience.

"Slow A is one terrific puller as his pedals his A in the 10-12 yr old class." Well, if good logic doesn't get you where you want to be there is always this kind of childish behavior to rely on.

I am a kindly old Grandad with gray hair.