I useally read the factory compression as advertised is a little higher then it is actually. I would guess you be around 9.5 to one with the taller block , thinking the 429 was no more then actually 10 to one with early block. Most shops will deck a given amount for around 100$. I would have take .025 off and call it good.It be better to install a rod piston in all four corners to get a better idea, if you dont mind the extra work.
Junkyard 429 build - compression question
So I'm building a 429 on a budget, and trying to limit the amount of machining I need due to both saving money, and the fact that there aren't really any reputable machine shops where I live that I've heard do good work.
So this is what I've got: I just picked up a 1969ish 429-2V out of a Mercury. It has the C9 heads and high compression pistons (flat tops with only valve reliefs). My research shows that it should be around an 11-11.5:1 motor (correct?). The thing must have sat for a while, and got some water in it, so the cylinder walls have pitting, and it can't be saved without being bored.030-.060 The heads all look good, and will just need a valve job with new seats, etc.
In addition to this motor, I've got a later 1973ish block with the taller deck height. This block is in almost new shape, with honing still visible, and only a very slight ridge at the top.
My plan is to swap the rotating assembly from the '69 block and put it in the '73 block and run the c9 heads. I'll get a re-ring kit for it and put all new bearings and what not while I'm at it.
I'm wondering what type of compression I'll be looking at with this setup. I don't know if the 69 block is 0-decked or not, but if it is and I use the '73 block with a .022 higher deck height, the compression calculator I found online puts me at around 10.4:1.
Am I close on this or am I missing something?
Thanks guys,
Jake
So this is what I've got: I just picked up a 1969ish 429-2V out of a Mercury. It has the C9 heads and high compression pistons (flat tops with only valve reliefs). My research shows that it should be around an 11-11.5:1 motor (correct?). The thing must have sat for a while, and got some water in it, so the cylinder walls have pitting, and it can't be saved without being bored.030-.060 The heads all look good, and will just need a valve job with new seats, etc.
In addition to this motor, I've got a later 1973ish block with the taller deck height. This block is in almost new shape, with honing still visible, and only a very slight ridge at the top.
My plan is to swap the rotating assembly from the '69 block and put it in the '73 block and run the c9 heads. I'll get a re-ring kit for it and put all new bearings and what not while I'm at it.
I'm wondering what type of compression I'll be looking at with this setup. I don't know if the 69 block is 0-decked or not, but if it is and I use the '73 block with a .022 higher deck height, the compression calculator I found online puts me at around 10.4:1.
Am I close on this or am I missing something?
Thanks guys,
Jake
1 - 10 of 10 Posts
Yeah, I'm going to go ahead and pop the rotating assembly in to get a better idea, but was just hoping someone would have an idea.
Thanks,
Jake
Thanks,
Jake
I have a similar combo - early heads, later block. I believe mine has '83 spec oem equivalent pistons and I was told to expect about 10.5:1 compression ratio.
--Ed
--Ed
He has a 429 not a 460 so he probably wont have 10 to one without decking
The stock advertised compression for the early 429 is 10.5:1, so you will need to cut .020"-.025" off to keep it in the same compression area.
In 1969, "ADVERTISED COMPRESSION RATIO" 429 2v=10.5 to 1 429 4v=11.0 to 1
I built a 1974 tall deck junk yard 460 and swapped the heads and never decked the block only had the heads resurfaced and the pistons were stock dish from the factory and with a .040 head gasket I had just about 8.82:1 compression. In your case you have flat top pistons and you are using 72 to 76cc combustion chambers and a none decked block will depend on the thickness of your head gasket they will range from .040 .051 .030 and the steel shim will be even thinner but you must have your block squared deckedSo I'm building a 429 on a budget, and trying to limit the amount of machining I need due to both saving money, and the fact that there aren't really any reputable machine shops where I live that I've heard do good work.
So this is what I've got: I just picked up a 1969ish 429-2V out of a Mercury. It has the C9 heads and high compression pistons (flat tops with only valve reliefs). My research shows that it should be around an 11-11.5:1 motor (correct?). The thing must have sat for a while, and got some water in it, so the cylinder walls have pitting, and it can't be saved without being bored.030-.060 The heads all look good, and will just need a valve job with new seats, etc.
In addition to this motor, I've got a later 1973ish block with the taller deck height. This block is in almost new shape, with honing still visible, and only a very slight ridge at the top.
My plan is to swap the rotating assembly from the '69 block and put it in the '73 block and run the c9 heads. I'll get a re-ring kit for it and put all new bearings and what not while I'm at it.
I'm wondering what type of compression I'll be looking at with this setup. I don't know if the 69 block is 0-decked or not, but if it is and I use the '73 block with a .022 higher deck height, the compression calculator I found online puts me at around 10.4:1.
Am I close on this or am I missing something?
Thanks guys,
Jake
and your cylinder heads resurfaced in order to use the steel shim head gasket which will give you up to a half a point more compression WR
Thanks for the info guys! Looks like I"ll be looking for some place to deck a block for me. Anyone know of any place good in northern Wisconsin area?
Jake
Jake
They also advertised the base 4 bl 429 like 360 hp? Advertised back then was just that.
1 - 10 of 10 Posts
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