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by tape it looks deep. what is it in thousandths? I dont know the the numbers for the 289 but could probably find them(maybe .015 from forums). throw all your measurements in to a compression ratio calculator and see what you get. visually from where I sit it looks like you have .100 or over. which i assume to be too much. but im not schooled in 289 yet.
 

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Looks like they are on 302 rods with a 289 crank. Check the rod forging number. C3 is 289 and C8 is 302. The difference is .065, about the same I see in your photo.
 

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I can't imagine you'd have much CR with those. The OEM pistons were flat top or flat top with a slight dish. Just the valve reliefs are going to cost you a lot of compression and that's on top of what appears to be entirely too much piston to deck clearance.

If you actually need the valve reliefs for bigger valves (aftermarket heads for instance) the KB116 is an excellent choice. I ran those on my 289 with AFR165 58 cc heads. Gobs of clearance for the larger valves and right at 10:1 CR. If your running stock heads, you're going to be looking for more of a flat top piston.
 

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Stock ford 289 piston and rod should be about .015" down .
302 and 289 pistons are the same the rod makes up for the longer stroke unless you have a boss 302, if uses the 289 rod length.

ken
 

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I ran those same pistons in my 289, which I believe are based on the old TRW forged pistons. Anyways, I have the TW170 heads from Trick Flow, and don't recall my pistons being that far down the hole. I couldn't get real crazy with the cam because they aren't Twisted Wedge compatible, but they worked just fine for me. You definitely have to take a look at the rods to see what's going on there.
 

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Discussion Starter · #10 ·



Not my engine … but I am looking and this is local. I was just curious what everyone’s take on this build was. From the photos it appears to be 289 crank in 289 block, unknown rods (just looking at the photos)
 

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Cobra, I'm thinking Randy is on target, and you have 302 rods riding on a 289 crank. They look almost identicle, you can't tell which is which without reading the castings numbers. Get yourself and early 302 crank and your problem will be solved. LSG
 

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I think we overthink this. The picture is simply a picture to show what pistons are in the engine and not necessarily the piston at TDC.

If that's the case, then the answer to your question is: yes, they are the correct deck height pistons and not the shortened type that are sometimes used to compensate for deck milling etc.
 

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Speed Pro forged double eye brow cut 289/302 pistons so the answer to the question is yes. They are decent pistons but may be a bit on the heavy side if you are going to spin the engine up.

Summit comment on those pistons; "Deck height 8.206 inch, deck clearance 0.011 inch, skirt clearance 0.0020 inch. ".

The build on an engine is only as good as the builder specifies and the monkey grinders that do the work. For a long block such as this I would want to see the balance sheet particularly since it has aftermarket pistons in it, crank is probably ground, stock pistons(rods rods rods) resized and it should also include the static compression work sheet. Since it has no damper and flex plate or flywheel I would guess it has not been balanced but its already assembled at this point. You balance your rotating assembly before you put it together.

I looked up the Blueprint heads and they are listed at 60 and 62 cc chambers which is a bit big for 289 compression unless the heads were shaved or not(probably not)? Double eyebrow cut pistons also steal back more cc's and lower compression unless you take some back somewhere else. It also should be run up on a dyno for break in and testing before it gets thrown into somebody's engine bay which is engine builder insurance in case some lifters are not functioning as they should. Brand new lifters not functioning properly is getting common now. In general, I am not impressed with Jegs rocker arms but they may be fine or not.

It may be fine or not but at the least it looks like it will be a low compression engine. I would look at the Blueprint long block with a box full of added on parts at Summit unless you know the engine builder.
 

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I have a complete balanced 302 rotating system, however, .040 pistons up fro grabs. Yeah, you can dump the pistons and use the rods. But, you need to be local, to heavy.
 

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The L2482F is a good piston. Forged and not cast. Compression height is 1.605 inches, giving a deck clearance with an 8.206 inch block and a 289 rotating assembly of .011 inches. The valve relief volume is 2.7cc which is only .7cc more than a stock "A" code piston. My only concern would be what head gasket is being used. My preference would be to use one with less than .040 inch compressed thickness... I'd probably go with an .027 or .030 inch thickness to keep quench as close to .040 inch as possible.

As for the $3100 price tag.... Seems like a good price but the flow numbers on the heads aren't anything special and, especially the exhaust, are killed by AFR 165's. With the combo shown, a .040 inch head gasket (common size) and stock deck height, expect a static compression ratio of 9.15:1. I'd like to see something a half-point (or more) higher... My other concern is the 2.02 inch intake valve and whether, or not, the builder has checked piston-to-valve clearance... I think, for 25-30% more, you could find a long block that not only has similar performance but also a roller lifter valvetrain and a warranty.
 

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COBRA5LADDIE,
If you are in CT , save yourself some aggravation and go see Phil @ PMR in Kensington CT. He is a Ford expert as you will see and has a full machine shop facility. He has a 10 second daily driver '64 Falcon and a cool '67 Ranchero "shop truck". It would be well worth your time.
Randy
 
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