As I discussed in other threads, I am building a motor for my son's truck. I have been told a few diffent answer to the final compression and was wondering what the collective views are here. It is a 93(ish) 350 4 bolt roller block with forged flat top speed pro pistons and a 64 cc head. Neither the block or the head has had any significant decking in the past.
Thanks in advance, Kevin
Have a look at the cam you're selecting and it should have a minimum recomendation.
I'd go at least 10:1
I believe it is in the 10s and that is what the cam is calling for, I was just curious if anyone knew what it would be with the above combo.
Got any valve relief cuts in the pistons? If so and theirs 4 of them then it should be about 9.3 to 1 if not about 9.7 to one assuming a zero deck height. I've got 1/8" knuckles on my pistons and I'm only pulling about 10.7 to 1.
Thank you, I believe they have 4 reliefs, I will have them in hand this week end.
Here's the calculator I use, works great. http://www.csgnetwork.com/compcalc.html (http://www.csgnetwork.com/compcalc.html) hope this helps.
boston14
Thanks, found one at Summit as well, 64 cc heads, with 4 vavle reliefs (+6.1 cc according to summit info sheet), .010 in the hole, .053 compressed gasket, it shows 9.7:1. At 0 deck height it is 10:1. They remaining uncertain is deck height, which I cant measure till the week end.
Thanks folks!
Checked piston heigth today, .015 in the hole, giving it 9.6:1 compression as long as the head gasket compressed thickness is .053 as I think. The thickness number came from an internet search, does anyone know for sure? It is a regular good quality Fel Pro blue gasket.
What number Felpro head gasket? They range from 0.015" to 0.071" thick and have bore diameters from 4.080" to 4.250", giving you a compressed volume anywhere from 3.2cc to 16.1cc. Quite a range and effect on compression!
boston14
Any way to tell which is which, not that it matters at this point I'm not gonna change anything. Just curious thats all.
The numbers are stamped into the gaskets.
Thank you, part number or compressed number?
Possibly both, but definitely the part number.
Steve,
Thanks, I was reading a little of you post down under. You're pretty creative and talented. Great job on creating a unique piece.
Thanks for the compliment.. It helps to be single and a little compulsive!
The stuff I have done is pretty easy. I found that out the hard way :P -by just having a go before deciding to pay someone. :D
Thanks Kevin. ;)