4-banger compression

I got a question for you 4-banger builders. I have a Model A engine with insert bearing, basicly a "touring engine". I've gone to grade 8 high tensile studs, and I'm wondering how high a compression head I can use on it. I don't want to push it, I just want a good running strong engine.
Any ideas ? Thanks, ace43

 

Model B head is 4.6-1.

 

I'm not a builder just a fan of the 4 bangers.

For after market there is synders 6:1 and 5.5:1 heads.

http://www.snydersantiqueauto.com/5358

also the November Banger thread.

http://www.jalopyjournal.com/forum/showthread.php?t=640029&highlight=banger

 

I'm a Banger Dude, go with a 6-1 and you will be happy.--TV

 

I'm running a 7:1 Lion Speed head
Its Super!

 

For street use, 7.5:1 will hold up well, just don't let it ping.

 

Hi Ace43...I weld filled my original A head and milled the chambers so I finished up with 7.1 compression...worked well .. but its hard on the babbitt rod ends ..only got 15.000 miles before I had to re babbit the rod ends...if your running a C motor with full oil pressure..probally wouldn't be a problem...got to be careful how much money you throw at it as you could build a nice S/V 8 for for less money...Doug

 

I would go with the 6-1. 7-1 one will knock on the hills unless you retard the timing or use high test gas.