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The car is a 1926 Model T coupe. 350 GoodWrench. All stock except for the performer intake and QFT-600-SL-VS Carb. 700 R4. Ford 8" rear with 3.80 gears. 2500 pounds. 28" rear tire. It has a couple of cylinders with unacceptable leakdown. So I am exploring my options for a new powerplant.
My first thought was to put an LS in it, but being slightly longer, and 4" wider, it just won't fit.
I could rebuild the Goodwrench engine. Maybe 250HP? I think I'm looking at $1500-$2000 machine work and parts plus the amount of time my Model T is down, probably a month or more. I hate it being down as it really is my DD. I have other cars, but it just ain't the same. Also don't want to do another flat tappet cam.
I am looking at a GM Performance L31-R. Vortec heads, hydraulic roller cam. 250 HP. About $2800. I would have $3300 or so in it finished. And it would be a weekend swap.
Or I could build a new 383 starting with a Skip White short block kit. Machined block. NKB aluminum 200cc heads, HR cam. I really don't care about 500 HP in this car, but a good solid, smooth running engine with great driveability is what I am after. I have a 383, 11:1, Profiler 210's, Straub cam, etc, 500+ HP in my roadster that absolutely screams. But that is not what I am looking for in the coupe. Actually 250 HP has been plenty of power in this 2500 pound car for 25K miles. But I guess a little more never hurt anything. :D If I build the 383, I would be looking for 400HP or so at the most. (My wife herds it occasionally.:sweat:) I could build this while driving the 'T'. SWP gives quite a few choices on building the 383. I haven't sorted out which version of short block I would need yet, but one of them would suit this plan. I would have about $4200 in it. If I decide to do the 383 I will get back to you guys before I hit the buy now button with specs for your approval.
With all the money saved sitting at home and a little stimulus money burning a hole in my pocket and being bored to death, I am ready to pull the trigger on a new engine. Just have to figure out which one. Thoughts?
 

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In a light car I'd prefer the 350 but I like 350's. Still a 383 could be tweaked, like with a single plane intake or the right cam n so on. Just it seems like for what you want any extra cubes or HP is just bragging rights but the cost of a 383 is the same pretty much if you go rebuilt and get a rotating kit like from Northern.

I would not suggest getting a cheap ATJ/Jegs crate LOL

 

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The car is a 1926 Model T coupe. 350 GoodWrench. It has a couple of cylinders with unacceptable leakdown. So I am exploring my options for a new powerplant.
My first thought would be letting the engine work go until winter... so can keep driving it... next would be determining if "leak down" problem is valves or rings... about $250 in cam and pistons can pump that engine up to around 325 HP... add another 1,000 or so usable RPMs... Also, a search will bring up several Goodwrench 350 build up articles from mild to wild for other ideas... The Goodwrench 350 came in 195 - 260 HP and 290 HP rated versions, the difference being a base level cam or 350 HP 350" cam... actual compression ratio on them is a low 7.6:1... hence the suggestion of flat top pistons for better MPG, more HP, sharper throttle response...
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What;s your threashold for unacceptable leak down??

a lot of used stuff out there with no problems beyond a little oil use at 30% leak, and not really any noticable amount down on power.

if it isn't smoking like a mosquito fogger I'd say drive it and enjoy in a couple more months, fix it over the winter.

How many miles on the engine?
 

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Discussion Starter #6
My first thought would be letting the engine work go until winter... so can keep driving it... next would be determining if "leak down" problem is valves or rings... about $250 in cam and pistons can pump that engine up to around 325 HP... add another 1,000 or so usable RPMs... Also, a search will bring up several Goodwrench 350 build up articles from mild to wild for other ideas... The Goodwrench 350 came in 195 - 260 HP and 290 HP rated versions, the difference being a base level cam or 350 HP 350" cam... actual compression ratio on them is a low 7.6:1... hence the suggestion of flat top pistons for better MPG, more HP, sharper throttle response...
.
This is the base level Goodwrench. Leakdown showed all leak going out the bottom. Nothing at exhaust or intake. So it definitely needs at least rings. Probably bored .030 to clean things up. Last bore job with torque plates was $350. Polish the crank. Resize the rods. Deck job would be nice. etc., etc., etc. I don't want to chance a flat tappet cam. I just don't want to worry about it. So retro roller....$800+. Freshen the junk smog heads?? Now we're talking money where the L31 starts to make sense. (I'm working on the story for the wife, here.) Now justifying the 383 might start to get a little tougher. I'll have to work on that.
 

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Discussion Starter #7
What;s your threashold for unacceptable leak down??

a lot of used stuff out there with no problems beyond a little oil use at 30% leak, and not really any noticable amount down on power.

if it isn't smoking like a mosquito fogger I'd say drive it and enjoy in a couple more months, fix it over the winter.

How many miles on the engine?
Awww he//, you guys are trying to talk me out of a new 383 build.
#3 is at 66% leak. #6 is at 28%. It's got one lifter ticking a little. No leaks. No noticeable smoke. Not much oil consumption, either. It's mostly just I know it ain't right. It eats on me. I was thinking once I got the T running with a new engine again, I could go through the Goodwrench and sell it to help defray the cost of the new one. There is only 45K on the Goodwrench.
 

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I'd put the $250 into the old engine and the rest of the money into the wife... but post her picture so we can see if I'm correct... LOL!

We can see you reflected in the door of the 'T'...
.
 

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Awww he//, you guys are trying to talk me out of a new 383 build. There is only 45K on the Goodwrench.
You sound like the lady I bought a sewing machine from to fix the canvas on my boat. She said it was starting to be hard to spin over. I told her prolly just needed a few drops of oil. She panic'd at that, didn't want to hear that, prolly had her husband talked into a new one... LOL!

I would expect that Goodwrench to go 200K miles without much trouble, unless over revved and bent a couple valves slightly... maybe a couple broken rings or ring lands... but no smoke sounds like it isn't very bad...

Maybe start acquiring bargains on parts for a 383 and build it over the winter... swap it early spring and then do the 355...
.
 

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Discussion Starter #10
I'd put the $250 into the old engine and the rest of the money into the wife... but post her picture so we can see if I'm correct... LOL!

We can see you reflected in the door of the 'T'...
.
Ha! LOL! It would take more money than that to turn her back into that 25 year old I married 42 years ago! :D
 

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My first thought would be letting the engine work go until winter... so can keep driving it... next would be determining if "leak down" problem is valves or rings... about $250 in cam and pistons can pump that engine up to around 325 HP... add another 1,000 or so usable RPMs...
Makes sense to me. I've seen a few of those Goodwrench 350s make more than adequate driver power with nothing more than 3/4 headers and a small 4bbl. And they were in 3000-3500 lbs cars. A true 9:1 compression with a mild cam (don't go crazy) would be great in a 2500 lb DD. And I wouldn't be afraid of flat tappet cam problems with stock springs or something like Comp #981 springs. Just break it in properly and you'll be good to go. For every engine build that has a lobe go flat, there are probably 50 others that run 50K miles or more.

Just occurred to me that those engines have exhaust valve rotaters. Have to say I'm not sure what that means for aftermarket spring and retainer selection.
 

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Just occurred to me that those engines have exhaust valve rotaters. Have to say I'm not sure what that means for aftermarket spring and retainer selection.
Yeah, some heads used shorter exhaust springs and others had deeper pockets and used standard height exhaust springs...
 

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66% in one cylinder only would concern me, but I'd pull the head before I decided anything if it's only one cylinder over 30%. Measure the and inspect the bore above the piston when at BDC. At 25k it shouldn't have a single cylinder issue.
 

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Makes sense to me. I've seen a few of those Goodwrench 350s make more than adequate driver power with nothing more than 3/4 headers and a small 4bbl. And they were in 3000-3500 lbs cars. A true 9:1 compression with a mild cam (don't go crazy) would be great in a 2500 lb DD. And I wouldn't be afraid of flat tappet cam problems with stock springs or something like Comp #981 springs. Just break it in properly and you'll be good to go. For every engine build that has a lobe go flat, there are probably 50 others that run 50K miles or more.

Just occurred to me that those engines have exhaust valve rotaters. Have to say I'm not sure what that means for aftermarket spring and retainer selection.
It means you toss the rotators in the scrap bucket when you change the springs ...
 

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Discussion Starter #16 (Edited)
Yeah I've done the leakdown on that #3 cylinder 3 times, hot and cold. Each time between 62 and 66% hoping it would change. It didn't. That's a big leak somewhere. No noise out the exhaust or at carb during leakdown. All out the bottom. So really bad rings? A chunk out of the piston? Gouged cylinder walls? Who knows, but this engine is going to need some serious attention in the near future.
Here's what's funny.
Compression PSI, Leakdown %
#1 157, 15
#2 160, 11
#3 147, 66
#4 152, 13
#5 163, 7
#6 148, 28
#7 157, 18
#8 152, 7
That #3 cylinder compression is a lot higher than I would expect it to be with 66% leak. #6 compression is about where I would expect it to be with 28% leakage. So what's up with #3? And what gets me is it's not smoking or using oil!
I'm not what you would call a mechanic, but I have been building and maintaining sbc race motors for over 50 years. I don't really know much at all about stock engines. 20% leak seemed to me to be about all I was willing to accept. Our race motors would get freshened well before they hit 20%. That 66% is really concerning. Coming from a race background, I always feel like I got to get it fixed before the weekend! You know what I mean.
The 383 in my roadster that I checked at the same time was all between 2 and 4%.
 

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That #3 cylinder compression is a lot higher than I would expect it to be with 66% leak. #6 compression is about where I would expect it to be with 28% leakage. So what's up with #3? And what gets me is it's not smoking or using oil!
Maybe the rings seal better when they're under tension on the compression stroke???
 

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Did you try adding some oil to #3 and #6 to see if it increased compression?

If you're a racer, I'm still suspecting slightly tweaked valves...
.
 

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Discussion Starter #19
Did you try adding some oil to #3 and #6 to see if it increased compression?

If you're a racer, I'm still suspecting slightly tweaked valves...
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Nope! This is my old man car. It gets driven pretty easy. I doubt it's ever been over 5 grand, if that. This car just doesn't "feel" like it wants to be driven hard. It's kind of an old ladies car. The roadster is for the adrenaline rush. I didn't try adding any oil, but I can give that a try.
 
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