I found a 429 2bbl in a 71' mercury marquise. I was just wondering what the power rating was on this motor. I'm guessing it was pretty low with the 2bbl. thanks

 

i believe ford rated 2bbl at 360, and 4bbl at 365, cj at 370, and scj at 375. anyone agree or disagree? engine should have dove-c heads on it also if factory engine

 

2V was 320, 4V was 360.

 

I'm actually surprised that its that high. thanks. The 71' has about 11:1 compression right, so will I be able to run this thing on 87 pump gas.

 

How about torque #'s

 

2v 320 4v 360 is correct... Compression should be 10.5:1 on a 71 ... It should go on pump gas okay. Torque rating of 2v was 460lbs ft and the 4v was 480lbs ft... Net torque.

 

the 1968 - 1969 - 1970 - 1971 429 4v engines were all rated at 11.0:1 compression from the factory..

 

cobrajet, you seem to know your stuff. Can you shed any light on this question that nobody else seems to be able to answer?

429 2V engines were rated at 10.5-1, but 4V engines were rated 11-1. Where did they get the extra half point on the 4V? The heads are the same, and as far as I know, the pistons were also.

 

all that i find out is that is what happens when you go from a 2v set-up to a 4v set-up.. these numbers are taken right out the Ford Service Manuals. i know the heads are the same. there was a slight variation in some intake manifolds, though if this made a difference i'm not sure. on some of the early engines Ford used a 4v intake manifold part number C8SE that supposedly sat the carb mounting surface a 1/4 to 1/2 inch lower on the engine for clearance, i have one of these intakes stashed away somewhere, i'll have to measure it against a regular one when it gets warm out.. the only other real differences in these engines from the 68 thru 71 and beyond years were the deck height on the blocks, if i remember right the 68 blocks had a taller deck height than what the 71 blocks had, i think the difference was .030 differences.. C.J.

 

I was under the (possibly mistaken) impression that all "ThunderJets" were 4V?

 

You are not going to be able to run that motor on 87 octane pump gas. Also 71 is a year shy of having the hardened valve seats. Depending on the altitude at your location 9.5 for big block is about all you are going to be able to run on unleaded regular. If you live above 500 ft you might be able to use pump gas.

 

cobrajet, actually the deck height was increased in mid 1970.

I don't see how an intake manifold can affect compression ratio. I always wondered if it was just creative numbering on Ford's part to make the 4V engine look hotter.

The cam timing affects staic compression ratio, but AFAIK, the 2V and 4V engines had the same cam and gears, too.

wtroger, I've been running a 429 for 17 years without hardened valve seats. No problems.

 

I live about 1000 ft above sea level, so will I be ok.

 

Sorry for the typo I meant to say 5000 ft above sea level.
IF your 429 is a 72 or later it has hardened valve seats if pre 72 it does not. Also if the motor ever had leaded fuel ran in it then the seats have some protection the lead stays there for a very long time. And the only time we have ever seen the valves sink badly is when the motors are run under heavy loads for extended time. But I have seen the valve seats hammered so bad that the valve springs would not close the valves. Take it for what ever it is worth. Lead substitue works pretty well. But if you are going to have head work done then the extra for the valve seats is something to look at.

 

yes your right i goofed on the deck height i got things backwards....

yes i do believe that all the thunderjets were 4v set-ups. all the ones i have seen in the past were 4v's..

the intakes i know would not have a difference in the compression but it was something i just wanted to state about these casting numbers for this intake.. C.J.