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Discussion Starter #1
Well, I was attempting to do a budget rebuild for my 289ci Ford, but I need new pistons. Old ones weight about 725grams w/ the pin. Would like to bump up the compression some, have some 60cc aluminum heads w/ 2.02/1.6 valves, not canted, so the pistons have to have big valve reliefs.

I've found a few cheap pistons, KB116 (9.3:1), KB115 (8.5:1), and KB365 (11:1). Only thing is the 116 and 365 are 19 grams heavier than my original pistons, and the 115 is 12 grams lighter. Compression ratios are all guessimations because I don't know how far in the hole the piston is.

I'm stumped on what to do here. I want to go with the higher compression, KB365 pistons, as the xe268h cam that I already have, calculates a dynamic compression ratio of about 9:1, which should be easy on 91-93 pump gas.

What would you do? Honestly if I could start all over I would just stroke the bitch and call it a day, but too much time/money wrapped up into this already and just want to get it in the car. Wish I could find some cheap used pistons, but can't find any anywhere near me.

Specs: 289ci, 4.030" Bore, 4.100" Head Gasket, Estimate piston is 0.030" in the bore. Never measured the stock pistons because it didn't matter at the time, was going to be a simple bearings and rings, until I pulled it all apart and realized I needed new pistons.
 

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Discussion Starter #2
Well, did some more figuring, the KB365 piston uses 1/16, 1/16, and 3/16 rings, vs stock of 5/64, 5/64, 3/16. So I'm essentially removing almost 1/2 of a ring. Measured my stock rings, one ring weighs in at 19 grams. So hopefully the ring difference will bring the piston difference down to an acceptable range. I've been reading, seems like 10 grams heavier or lighter is max you want to go. Some state even double that is good. What's your opinion? Obviously balanced is preferred, but I really don't want to spend the $450 it costs to get it balanced, because with that, and cost of pistons, I may as well have gone with a pre-balanced stroker kit, and I've already gone way to deep into this project.
 

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11:1 is way too much for the 268HE cam. You'd end up having to run Av-Gas or Race Gas in it. With the 268 cam, you'll want to stay around 9.5 to 1 static. You probably do this, but be sure to do the math, and consider your head's chamber volume in calculating a true CR.

Balancing is highly recommended. $450 sounds really steep. it's a lot less than that around here.

With your aftermarket heads, a stroker kit would be a great call. Do it once. Do it right!

Good Luck!
 

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Discussion Starter #4 (Edited)
Hmmm, I already bought the pistons, but easily returnable. I was thinking I'd be okay with 11:1 with aluminum heads, 93 pump gas, and the dynamic compression ratio with the cam was something like 8.5:1, I'd have to check again for sure though. The only two other pistons that would work with my heads, one gives a 9.3:1 CR, but it's 20 grams heavier, and does not have the thinner/lighter rings, so i will run into weight mismatch that is most certainly too big of a difference. Then the other was like 8.5:1, flat top, but I think that one was forged, and way heavier also, but could do a lighter pin, I can't quite remember that one's specs because I wanted to bump up the compression some, and believe that was more expensive being forged, and the cost of lightweight pins. I wish I could find a set of used pistons for 9.5:1 or so, but I cannot.

The KB365 pistons are 10.9:1 with a .041 head gasket and .030 in the hole, and 11.05:1 with a .047 headgasket and .020 in the hole, so I think it's a definite 11:1, but I need to measure before coming to a conclusion, that's why I purchased a set, was going to use one and check the depth before installing everything. Thinking I'll run the 0.047 headgasket either way though, as that's 10.7:1 if they're 0.030 in the hole, which is a tad better.

I bought the heads in because I knew they would be good for a stroker motor, plans for the car are a 408/418/427ci windsor, heads might be on the small end, but they were dirt cheap, so porting them will be budget friendly. When I get there, I do not have the money for that right now, that will be after the body work, and change the front suspension. Years ahead of me. But now i'm wishing I would have waited and spent the money on a pair of canted valve heads, because then I would be able to just use a set of stock pistons, and more than likely be okay with stock fly cuts and my cam/head combination.

This is all becoming a cobbled up mess of a motor...
 

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Discussion Starter #5
For some added info, my pistons weigh about 724 grams with pins, the ones I was looking at are all Keith black pistons as followed:

KB115: 713 grams with pins, standard rings

KB116: 743 grams with pins, standard rings

KB365:743 grams with pins, but have the smaller rings, so should take off around 10 grams

There's also a set, KB312 that are like 2 grams heavier, so would be a nice match, but I cannot find for sure if they're designed for canted valve, or inline valve heads, but they appear to be for canted valve heads via pictures? But they're a great match in weight, and give me 9.5:1 compression.

At this point, I'm leaning towards canceling my order of the KB365, and just going with the KB115, 8.22:1 calculated compression, as they're ~$60 cheaper, weigh less, so crank will be overbalanced, which seems to be better than underbalanced, and it just simplifies everything. But I just cannot decide. I'm lost on what to do, too many variables.
 

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For some added info, my pistons weigh about 724 grams with pins, the ones I was looking at are all Keith black pistons as followed:

KB115: 713 grams with pins, standard rings

KB116: 743 grams with pins, standard rings

KB365:743 grams with pins, but have the smaller rings, so should take off around 10 grams

There's also a set, KB312 that are like 2 grams heavier, so would be a nice match, but I cannot find for sure if they're designed for canted valve, or inline valve heads, but they appear to be for canted valve heads via pictures? But they're a great match in weight, and give me 9.5:1 compression.

At this point, I'm leaning towards canceling my order of the KB365, and just going with the KB115, 8.22:1 calculated compression, as they're ~$60 cheaper, weigh less, so crank will be overbalanced, which seems to be better than underbalanced, and it just simplifies everything. But I just cannot decide. I'm lost on what to do, too many variables.
Save your money until you can do it right. 11:1 will NOT work with a 268HE cam... and 8.22:1 will be a dud. I recommend not eating out at restaurants, cutting back on 'entertainment' etc... until you have enough coin to buy the stroker kit you want.

You can throw money down the drain with something that isn't going to make you happy, or you can continue to cut back and save for something that will be worthwhile.

There's never time to do it right... but there's always time to do it AGAIN.

Good Luck
 

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Discussion Starter #7
I suppose, you are right, I better do it the right way. Cheaper in the long run. I'll look for a piston that better suits my needs.
 

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With your combination of 4.030 - 2.87 stroke -.030 below the deck , and 60 cc head , you would need a +10 cc domed piston to get 10-1 Compression ration that would be good for an aluminum head. I found one in the Racetec/Autotec piston catalog , 1000416 that would work for you. The +11.2 dome would give 10.3 that would still be fine on 91 octane.
Randy
 

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Discussion Starter #9 (Edited)
Thank you for the help, it is much appreciated. But my block has a lot of rust pitting, and already .030 over, so I am thinking of just going with the 408w I originally wanted. Taking up mike's advice of just waiting, and working a lot of over time now to save up money.

Thinking of going with a Scat crank 4-351W-4000-6200, eagle rods CRS5090F3D, and DSS 8723-4030 Pistons. That all costs $1500, then will have to get the 351w block that I already have bored, and deck squared. And of course balance the rotating assembly. Estimating it at about $2200 for the short block, hopefully less if I don't have to add metal to the crank. Then clevite tri metal, or king bearings, depending on cost/other's opinions. Setup should be right around 10.5 compression. Might pick up a different cam, and use this one in my other stock 351w, not the best cam for the motor, but better than the stock cam.

Also contemplated doing a budget 393, but stock rods seems like a ticking time bomb, and I want this motor to last. Save that fun project for something else.

Unless I wind up with a 302 block in the mean time, then I'll just have more money for more things.
 

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Don't count out the 392 stock rod combo. The 351W truck rods with the football headed bolts are plenty strong. I have built several without any issue. Use the series 9000 cast steel crank and limit the revs to 7,000 and you sould have a 500 hp terror for moderate cost. Look for a 94-95 block and you can use factory hydraulic rollers saving a ton more money. With 3" diameter mains the crank is PLENTY strong.
Randy
 

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Discussion Starter #11
I had no idea car and truck rods were different, just went an checked and I do have the "football rods". Think you just changed my mind on what to do! Sadly, my motor is from a 1980s F150, so non roller, but! it was free, and can't justify the cost of linked roller lifters at this time. Plus I originally got this motor for the car, just at the time couldn't spend $600 on headers for it. Using Scat's 9-351-385-5955-2311W crank, and Summit's SUM-17370FC-30 Forged Pistons, should be around 10.5:1, and that's only $640 in the bottom end. More than half the cost of the 408w! Thank you very much for that insight, was $800 advice!
 

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I had no idea car and truck rods were different, just went an checked and I do have the "football rods". Think you just changed my mind on what to do! Sadly, my motor is from a 1980s F150, so non roller, but! it was free, and can't justify the cost of linked roller lifters at this time. Plus I originally got this motor for the car, just at the time couldn't spend $600 on headers for it. Using Scat's 9-351-385-5955-2311W crank, and Summit's SUM-17370FC-30 Forged Pistons, should be around 10.5:1, and that's only $640 in the bottom end. More than half the cost of the 408w! Thank you very much for that insight, was $800 advice!
You have a 289, and were asking about that... and now people are giving you advice on stroking a 351W. Rotating assemblies for the two engines are not compatible.

If you want to do a 351W swap into your car... and have a 351W engine to work with, it's the best thing you can do. The 351W bolts right to the 289 engine mounts, and even has the same balance. You just cannot install a 351W stroker kit into a 289 engine.

If you go with the 351W platform, the 393 stroker kit uses a 3.85" stroke crank, 351W rods and 302 pistons. If you have an engine to work with, it's the original stroker kit that came out before the rotating assemblies started to get really cheap. Nowadays, most people step up to a 408, as they are generally using all aftermarket parts, anyway. The 408 kits are also usually higher quality, balance easier, and are a 4" stroke.
 

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Discussion Starter #13 (Edited)
You have a 289, and were asking about that... and now people are giving you advice on stroking a 351W. Rotating assemblies for the two engines are not compatible.

If you want to do a 351W swap into your car... and have a 351W engine to work with, it's the best thing you can do. The 351W bolts right to the 289 engine mounts, and even has the same balance. You just cannot install a 351W stroker kit into a 289 engine.

If you go with the 351W platform, the 393 stroker kit uses a 3.85" stroke crank, 351W rods and 302 pistons. If you have an engine to work with, it's the original stroker kit that came out before the rotating assemblies started to get really cheap. Nowadays, most people step up to a 408, as they are generally using all aftermarket parts, anyway. The 408 kits are also usually higher quality, balance easier, and are a 4" stroke.
Yeah, we got off track from the original question, I have a 289 block, and a 351w block, and a bunch of other blocks... Thinking of 393 over 408 due to it being half the cost. Eventually step up to a 408, but for what I want to do with the 408 (427ci) would require an aftermarket block, and e85/mixed fuel, and is not in the budget for quite some time, and want to be able to run pump gas until I can get some of the other projects running and driving, so I can actually have fun with the car. Better off going budget stroker for the time being. But if a good 302 block falls into my lap, I will just go with the 302, since it's cheap.
 

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n2omike
Post #9 near the end mentioned the idea of a 392 stroker and is the reason I went "off topic".

Further off topic , what does you 306 run on "motor only" . I am only curious as to how much you pick up with the spray as I am contemplating it. Randy
 

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Discussion Starter #15 (Edited)
What's the average cost for machine work around you? Started pricing out this 393, it's up there. There's only one machine shop around me, and their quotes were $225 to square the deck, $350 to bore w/ a deckplate, or $280 w/o, thinking for piece of mind I best use the deck plate? cleaning is $135, then balancing is around $300, depending on if metal is added. Then I was also thinking of going with a windage tray, and main studs, as it's a front sump car, which will most likely require a line hone, which I think is $180, I forgot to ask of course. That's like $1200 in machine work... then another $2800 on top of that intake to oil pan, minus heads, and w/ headers. Is $1200 in machine work justifiable on a "budget" 393?

Or I could go full "budget build" Just clean the deck surface up, use a ridge reamer on the cylinder walls, and hope that the main bores don't distort w/ studs, and if they do, just run the original main bolts, and no windage tray?
 

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n2omike
Post #9 near the end mentioned the idea of a 392 stroker and is the reason I went "off topic".

Further off topic , what does you 306 run on "motor only" . I am only curious as to how much you pick up with the spray as I am contemplating it. Randy
Well, the engine is kind of unique compared to what most people do. All the parts were sourced around 1995, just before all the cheap Chinese Stroker stuff started coming out, so it's still 306ci. It uses an old 1970 0.030"/0.040" Boss 302 steel crank and rods. It's built to be a STREET car, so it has a pump gas compression ratio and a solid flat tappet cam. (SFT were cheap, reliable and would rpm easily)

The cam/compression/gearing, etc are geared toward nitrous... so it's designed to be optimized for the bottle, which is an old Top Gun plate from the early 90's jetted for 200hp. A guy from Top Gun is who broke away to form Nitrous Express. I had the same kit on an old 289 headed engine jetted for 150 hp. After the engine was getting well worn, the nitrous was stepped up to 200 hp to compensate for wear, and has been there ever since. lol The current engine has been on 200 hp worth of the drugs from the beginning... which is around a dozen or so years, now. It was taken out for a freshen-up a few years ago, and showed no real signs of strain. Both engines have digested dozens of nitrous bottles without issue. The key to not killing them, is to not get greedy, and be conservative. A 'soft' tune can go a long way in regards to service life.

As for how they run off the bottle... I don't get to go to the dragstrip that often, so when I do I like to make the best of it! That means, I want to go as fast as possible, so pretty much every run is ON the bottle. With the drugs, the driver's seat is a BUSY environment! The 1/8 mile goes by in 6.29 seconds, and you're already in 4th gear before reaching the finish line. There's no time to think... It just has to be driven by instinct. OFF the bottle, it feels like everything is moving in slow motion, and I sometimes tend to shift too early. It's just not nearly as much fun, so almost every pass is a bottled one. lol

Most tracks around here are 1/8 mile. Going to a 1/4 mile track is a rare treat. The old engine was a 306 with 289 heads I ported. The best 1/8 mile times it produced were 6.73 @ 103 on the bottle, and 7.48 @ 93 naturally aspirated. For the naturally aspirated runs, a buddy with a 400 Camaro and I were really close performance wise off the bottle. (his car didn't have nitrous) so we kept making runs, and kept upping each other's best times! It kept going back and forth until I was launching my car wide open on the rev limiter at 7200 rpm! Shift point was only 6800. lol Since it was set up for the bottle, it would launch as hard as you wanted to off the bottle. Was a fun night. lol

I've only made ONE run with the current engine naturally aspirated. lol It was a warm day on a 1/4 mile track and ran 7.44 in the 1/8 and 11.66 in the 1/4. I'm sure it would do better, but with only getting to the track a couple times per year, I've always got the bottle turned on... as it's just a lot more fun and exciting. lol

The bottle is activated via a throttle switch. When the throttle is wide open, the nitrous is ON. The car is launched at 3/4 throttle. You just 'barely' lead with the clutch before going WOT, as you don't want the nitrous to come on before the clutch is released... or it tends to get violent. lol But, as soon as the clutch it starting to grab, the nitrous is on. It's all done by feel and just timing your feet. The bottle adds a MASSIVE amount of torque for launch, and improves that little 306's 60ft tremendously. The nitrous can also be switched to 'button' mode, so it's activated via a button on the shifter. This was used mostly in the street racing days, and for testing/playing around on the street. lol

I'm 51 years old, and have had the car since age 15, when it was bought as a beater first car for $1,300. We've been through a lot! lol

Well, that was a lot of rambling... Sorry for making you read all that, just to answer a simple question. :)
 

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All good thanks Mike .
I have raced my '66 Shelby continuously for the last 45 years. The current 331 has run 7.04 and 11.13 respectively. This is with a C4. I think my "old school" Ford dual four intake is holding me back fro a 6.9-10.9 et slip. I have a Vic Jr and if I had the ambition , (I'm 66) I would change it. My goal is to get a 9 second time slip on motor only and to do that I am building a 374ci all aluminum Boss 302 stroker. After seeing you pick up over a second with spray , I may rethink finishing the big engine. There are some videos of my car on you tube . It's a white '66 GT350H.
Randy
 

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All good thanks Mike .
I have raced my '66 Shelby continuously for the last 45 years. The current 331 has run 7.04 and 11.13 respectively. This is with a C4. I think my "old school" Ford dual four intake is holding me back fro a 6.9-10.9 et slip. I have a Vic Jr and if I had the ambition , (I'm 66) I would change it. My goal is to get a 9 second time slip on motor only and to do that I am building a 374ci all aluminum Boss 302 stroker. After seeing you pick up over a second with spray , I may rethink finishing the big engine. There are some videos of my car on you tube . It's a white '66 GT350H.
Randy
That intake is DEFINITELY holding it back! A Victor Jr would likely put you right where you need to be! Sure would be nice to dip into the 6's and 10's with the current engine! Once you do that, then it could be retired, and you could go to work on the Big Engine!

Do NOT give up on that cool Boss 374! Try not to get too worried about numbers. It will be what it will be! Just go out there and optimize the car once you get the engine installed, and enjoy it! I have a feeling it will run GOOD!

Most cars don't pick up as much as mine on the bottle... especially considering it's 'only' a 200 hp plate. If you do go that route, you'll want to get with someone who really knows what they are doing... If you are using a factory block, it's even more important, as those can be the weak spot. A person has to take ALL precautions to avoid detonation... as THAT is what will kill a block that is at or near its limits.

On mine...
The compression ratio is well into the 'safe' zone.
Cold Race Plugs.
Not greedy with the timing.
I run it lean, but not excessively lean. (lean makes power!)
Better fuel than you think you'll need.
ONLY run the engine with a COOL engine temp! Warm engines are more likely to detonate.
Mine is a stock stroke, which puts less leverage on the block, and allows more power to be run through it.

I have an electric fan and water pump. Between runs, I hook it to the battery charger and cool the engine down to where it feels cool to the touch... then run it as little as possible up to the lanes for the next pass. Doesn't take long at all with BOTH the fan AND water pump.

For now, PUT A VICTOR JR ON IT!!! It will be fun to see what kind of a difference it might make!

Good Luck!
 

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Thanks Mike ,
The manifold swap is on the "to do" list. The dual fours look cool and do make power , but there is no doubt the Vic Jr ( especially my "worked" version) will make more power. I have so many runs as it is that any change will show up no matter what time of year or track conditions. Once in the tens , I will finish the 374 and set the 9 second goal in place. As in yours a 200 hp increase "should do it'', and the 374 has that capability. Thanks .
Randy
 
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