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Discussion Starter #1
You might recall earlier posts of me whining about my 351W engine being down on power from what I expected (about 75 HP shy of advertised HP). I found an interesting link the other day about how to distinguish World Products heads by the info they cast into them:

www.worldcastings.com/tech/4PgGuide.pdf

My builder specified in the build sheet that he used Windsor Jr. iron heads on my engine. However, it says in the above article that a Windsor Jr. Head will have J/R cast into it, whereas the larger runner Windsor will say "Windsor". Well, I popped off a valve cover real quick and there was "Windsor" looking me in the face :shocked2:

I bought this engine as a long block from an out of state builder who, as far as I can tell, is no longer in business (always makes you feel warm inside).

Anyway, I noticed on the spec sheets that the Windsor head has a much larger combustion chamber than the Windsor Jr.(64cc vs. 58cc), which now has me wondering what my actual compression ratio really is. Builder specified it as 9.5:1, but now I have to wonder if he built it with windsor Jr. heads in mind, or the windsor heads (I know for a fact that he ordered the heads from a parts house and slapped them on the engine, then shipped it to me. They were holding up him completing the engine for a while, imagine if he got the wrong heads and just slapped them on without knowing!)

Am I correct that he would have had to use different pistons, or milled the windsor heads or something to adjust for the difference between these two heads, in order for compression ratio to be equal between the two??

It would seem to me that the CR could really be somewhere around 8.7:1 (quick, rough guess based on online calculators) if he built the engine for windsor jr.s, then stuck the windsor heads on there. :pissed:

Is there a way I can figure out what I'm really dealing with?

If I could, I would really like to take off the World iron heads and install AFR 185 58cc heads in their place. The reasoning being that if my engine is actually at 9.5:1 compression right now (with the larger 64cc chambers), then I should see a bump of almost a point in compression, but since the heads are aluminum that would be a good thing anyway. If the motor is at 8.something:1 right now, and I put the AFR's on there, it should bring me up to the 9.5:1 ratio originally intended, which maybe wouldnt be ideal for aluminum heads, but should be better than what I have right now. I would love to install AFR 185 heads and be done with it, but then I'm afraid the valves would hit the pistons! Is there anyway I can tell if I could run the AFR 185 58 cc's on this engine?

What would you do? I'm just trying to get some real power out of this mystery 351W!
 

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Discussion Starter #3
Ya, I know online calculators are just a rule of thumb, that's why I'm asking you guys that know much more than I do about how to find out for sure.

I know the engine has stock 351W rods and crank, but it has .030 over TRW hypereutectic pistons. I know the procedure to measure the cc's of a cylinder head combustion chamber, but will it be possible to determine what kind of compression ratio I would have with the current heads combined with the effect of the piston selection he made?

Ever since I bought the long block, I've wished I would have just waited to replace the engine, and did all the work myself, then I would know for sure what I really have. Thanks in advance for any other helpful ideas!
 

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Just do a compression check. That'd at least give you an idea.
An idea of what? Static compression ratio? Not likely.

If it were me I would pull the heads and cc them.

I'd also verify piston to deck clearance and type of piston.

That's how you'll be able to verify static compression ratio.
 

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BTW, if in fact your down 75hp, all other things being equal, you're not likely to find it in the heads or 1.5 points of compression.

In view of the fact that you believe the heads are wrong....what else might be not right??? ::
 

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Discussion Starter #7
BTW, if in fact your down 75hp, all other things being equal, you're not likely to find it in the heads or 1.5 points of compression.

In view of the fact that you believe the heads are wrong....what else might be not right??? ::
Thanks for the info. I agree with your comment. At this point, everything about this engine is suspect. That's why I'm trying to get back to basics as much as possible and figure out what exactly I have, and then make decisions from there. What I don't want to do is throw expensive parts at it and create even more of a frankenstein with no gain in power.

I too don't think I will magically find 75 HP in heads and the compression ratio alone, but maybe these items mixed with some dyno tuning, verification that the cam is the one promised (as well as making sure it's the most appropriate for this setup) and who knows, I may find that missing power.

Thanks for your suggestions. Keep em coming :: I'm hoping I will have time over the holidays to crack the heads off of it and see what is going on in there.
 

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I'm with the others ... the only way you'll ever know what you have (or don't have) is by tearing it down. Basically, the way I see it you have 2 choices ... tear it down and see what you've got or live with it.

I feel for you. When I was trying to decide what to do with the engine in my '69, I talked to several mail order companies. I just couldn't get a warm feeling with any of them. As soon as you asked about warranty, most started stuttering. The one company, when I asked how I should get them my flywheel for the balance job, his response was "oh, we don't need the flywheel to balance it" ... in other words "we have no idea what a blance job is, so we'll just blow smoke up your a$$ and tell you we did it".

I ended up going with the local builder that's built my last 5 engines (none of which I've ever been able to blow up *LOL*). We decided, together, what was going into the engine, and I have all the documentation that came with every part for my files.
 

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Discussion Starter #9
John, I know what you mean... with everything I went through to get this engine at the time I ordered it, by the time it arrived at the freight dock, I was just thrilled that it was actually a 351W FORD engine!! True to form, it even showed up painted black, even though I had told him Ford Blue (what an Ahole)

I'm thankful that I have a good block and a good foundation that, should it come down to it, could now be rebuilt fairly inexpensively, and you can bet this time it would be either done by a trusted pro, or by me with help from engine building friends and the forum!

This whole experience of trying to diagnose problems I didn't create is so much harder than just building the engine myself, it's ridiculous, and frustrating.

Ohh another thing about the mail order guys, recently I found a crate engine online that I liked the specs on. It is similar to my engine, and it made good power, and so I was curious to find out exactly which cam they were using in it. I called twice, and one guy said a comp cams grind, the other said it was the Performer RPM cam. When your job is all about the details, how can you not be able to provide the details!!! :pissed:
 

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If they're Dart windsors that's a good thing. My brother has the same heads on his 302. His car has 100 more rear wheel horse power than my 93 lightning. He gets 24-26 MPG on the highway. High 12's low 13's at the strip @110.
If I were you, my main concern would be that unless pistons for this application were used or flycut for the valves there is a real possibility of contact. Regular pistons have to be fly cut for vavle clearance.
 

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well, while mustangjoe may be right in saying that you may not find 75 hp in the heads and CR, i bet if your engine builder did use them thinking they were Victor Jr, i bet you find close to most of that 75 HP. I thought the general rule of thumb was about 30 hp gain from an entire point of compression. So, a 1.5 change in compression would give about 40-45 hp gain. Who knows what other advantages the heads have over the ones you have on now, like their flow characteristics and whatnot.

Chaz
 

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I have seen many experienced engine builders use 3%-5% peak gain for each point of compression as a general rule.

In order to "bolt on" 75hp with just a set of the heads we are talking about, the rest of your combo better be almost perfectly matched. And even then, the question of valid "dyno numbers" will come into play. ;)
 

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Discussion Starter #13
Thanks again to everyone for the responses!

I think the approach I'm going to take is popping the heads off, having a look at the piston type and the piston to deck clearance, cc'ing the combustion chambers on the head, and pulling the cam out and having a look at it to try to determine the grind. (I think they stamp it on there, right?)

Once I have that info, I will probably come back here and ask you all again for advice, along with calling some cam companies, etc., and by putting together the appropriate mix of parts, I should be able to get the power I'm looking for. I don't think I'm being too unreasonable to expect over 300 flywheel hp out of this engine.

It seems like the short block is ok. Oil pressure is great, and the compression test I did a few weeks ago came out dead even at around 183 on every cylinder. No strange noises from down there or anything.

Now, the only things standing in my way are time and money :highfive:
 
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