5.9 stroker build

[68ss]

Both points well taken. I'm ordering this stroker kit from Hughes:
View attachment 1716364084
TF heads measure 60cc combustion chambers, which lowers the CR to 10.3 or 10.4:1, depending on which calculator you use. That's right in the ballpark where I want to be with 91 octane and aluminum heads.
Thanks for reminding me about Dwayne Porter. He has serious street cred both here and on FBBO; I know he's a member on both. I need to start with him on my cam selection.

that CR seems high for 91 octane if you want to be in a good quench zone with correct gaskets. I'm no expert, but don't you want to be around 9.5-9.7:1 even with aluminum heads? My motor is 10.2:1 and I run aluminum Eddy Performer RPM heads on my 451 and still detonate unless I keep the timing 32 total or less. I'm running .037 thick Cometic gaskets.

 

[Kern Dog]

The wider the bore, the greater the risk of detonating, from what I’m told.
The 360/5.9 bore is 4.00 stock, compared to 4.34 for a 400 block.
If this were my build, I’d aim a bit closer to 10.0 even but I admit, I’m not as experienced as others here.
I’m at 9.8 with a 440 block.

 

[RBConvert]

I would steer clear of Hughes. Lots of places to get stroker kits. There's a guy in here selling them. Hughes customer service is terrible. Unless you enjoy a guy treating you like you're an idiot over the phone.

I've dealt with Dave several times over the years. The cam and valvetrain in the Coronet is all Hughes. I agree that he's not the easiest person to deal with. You need to at least have a plan before calling. When I talked to him last week he was cordial, even said 'thanks for calling' before hanging up. That said, most recently I've dealt with Tom over the phone.

 

[RBConvert]

Why not reach out to members @PROSTOCKTOM or @Rocket? They both have stroker assemblies available.

I see PROSTOCKTOM's ads in the performance classifieds. The ads are for Molner forged crank, forged pistons, etc., which is overkill for what I need. I didn't think to ask him about other options. It's not too late, Hughes hasn't filled my order.

 

[RBConvert]

that CR seems high for 91 octane if you want to be in a good quench zone with correct gaskets. I'm no expert, but don't you want to be around 9.5-9.7:1 even with aluminum heads? My motor is 10.2:1 and I run aluminum Eddy Performer RPM heads on my 451 and still detonate unless I keep the timing 32 total or less. I'm running .037 thick Cometic gaskets.

The 440 is at 10.5:1 with Stealth heads. Timing is limited to 34°. Any higher and it does knock. I could install a thicker gasket if need be.

 

[mopowers]

Great looking Dart. I vaguely remember seeing it in Auburn at one of their cruise nights a couple years ago. I'm building a 408/360 myself. Just picked up the rotating assembly from it's balance job today in fact. I went with a Scat kit myself. Looking forward to seeing how yours progresses.

 

[Kern Dog]

THREE Northern CA Dart owners and we are ALL building 360 based engines??

 

[RBConvert]

Great looking Dart. I vaguely remember seeing it in Auburn at one of their cruise nights a couple years ago. I'm building a 408/360 myself. Just picked up the rotating assembly from it's balance job today in fact. I went with a Scat kit myself. Looking forward to seeing how yours progresses.

We've been taking the cars up to Auburn for 10+ years now. We go in May, June, and September, skipping July and August. Hopefully we'll see you this year.

 

[RBConvert]

Greg and I have torn down three other engines over the past few months, including a couple of 383's. In one of the 383's, the pins were corroded to the piston and it took us almost an hour to drive the pistons out of the bore.
I don't know how many miles are on my engine. At lease 20K while in my possession, plus whatever the PO accumulated. I'd say 25K-30K miles is a reasonable guess.
On the engine stand, pulling the valve covers, intake, and front cover we were greeted to an engine that internally looked brand new. This one runs a mechanical fuel pump.

Looks like there was a small leak at the front cover. Mopar didn't install an oil slinger; we're going to put one on during reassembly.

Standard bore with dish pistons.

No ridge. The pistons practically fell out of the bore with just a few taps. Our machinist confirmed only .004-.005 taper.

 

[RBConvert]

All the bearings were in terrific shape, rod and main journals too. The internals validates the care that I took with this vehicle. Regular oil changes with high quality synthetic oil, Wix filters. When driving around town, I always get the motor up to operating temp for an extended time to burn off any condensation.

 

[Kern Dog]

For the record, the # 1 piston:

...was cleaned after the head was off. There is no way that a piston would remain this clean after the engine has ran awhile.

We cleaned it to do a rudimentary measurement of the deck clearance. I don't recall how far below deck these were and I'm not sure of how big the dish is. These were rated at 9.0 to 1 though, right? The smaller "Magnum" series combustion chambers helped out with the compression ratio.

 

[TT5.9mag]

For the record, the # 1 piston:



View attachment 1716364995

...was cleaned after the head was off. There is no way that a piston would remain this clean after the engine has ran awhile.

View attachment 1716364996

We cleaned it to do a rudimentary measurement of the deck clearance. I don't recall how far below deck these were and I'm not sure of how big the dish is. These were rated at 9.0 to 1 though, right? The smaller "Magnum" series combustion chambers helped out with the compression ratio.

All of the magnums I’ve disassembled were .053-.054 in the hole.

 

[Kern Dog]

I think I measured around the .050 number, give or take.

 

[RBConvert]

The parts are starting to trickle in.
First to arrive were the TF heads, p/n 61417802 specific for hydraulic roller cams.

60 cc chambers

I think everyone is aware, because these are LA patterned heads on a magnum block, the rocker shafts have to be oiled through the pushrods. TF highly recommends Harland Sharp, p/n S72026K for 1.6 ratio and S72025K for 1.5 ratio. Both retail for well over $900. Horsepower don't come cheap.
I've read several posts touting B3 Racing and how they correct rocker arm geometry. Honestly, I don't quite understand all they do and the significance that they play in correcting valve train geometry, but I'm planning on giving Mike a call.

 

[mopowers]

The parts are starting to trickle in.
First to arrive were the TF heads, p/n 61417802 specific for hydraulic roller cams.
View attachment 1716368398View attachment 1716368400
60 cc chambers
View attachment 1716368401 View attachment 1716368402

I think everyone is aware, because these are LA patterned heads on a magnum block, the rocker shafts have to be oiled through the pushrods. TF highly recommends Harland Sharp, p/n S72026K for 1.6 ratio and S72025K for 1.5 ratio. Both retail for well over $900. Horsepower don't come cheap.
I've read several posts touting B3 Racing and how they correct rocker arm geometry. Honestly, I don't quite understand all they do and the significance that they play in correcting valve train geometry, but I'm planning on giving Mike a call.

Great looking set of heads. Do you know if they have helicoils for the rocker shaft, intake, and exhaust mounting threads?

 

[Kern Dog]

Your build does step things up a bit from where I have been with the LA/Magnum engines. This will be a learning experience and reporting on it here will help people in the future.

 

[RBConvert]

The Hughes stroker kit arrived earlier this week. To repeat, I bought the cast crank, forged Icon piston, with Scat I beam rods. The pistons are dished with asymmetrical cutouts for intake and exhaust valves. For sure I will be double and triple checking that I install them in the correct bore.
They're floating wrist pins, so for s&g's I mocked up a set.

This week I bought a small digital scale from HF. It can weigh up to 11 lbs/5000 grams. I weighed all the pistons, pins, and con rods. Five of the pistons weighed 487g, the other three weighed 488g. Pins were evenly split between 114 and 115g. The con rods had one weighing 575g, four weighing 576g, and three weighing 577g. If I hadn't measured and had randomly paired the lightest piston/pin assembly with the lightest rod, and vice versa paired the heaviest with the heaviest, the max variance was only 4g. Mixing and matching, I got six piston/rod assembly's to come in at 1,178g and two combos at 1,179. Better yet, each heavy is on the opposite cylinder bank. The effect on the rotating assembly is negligible, but it was a fun exercise.
Tomorrow the pistons and cam bearings go to the machinist.

 

[RBConvert]

Great looking set of heads. Do you know if they have helicoils for the rocker shaft, intake, and exhaust mounting threads?

Yes, they're helicoiled.

 

[mopowers]

Man, those parts are pretty aren't they? Not sure if you noticed, but there should be a more pronounced chamfer on one side of the connecting than the other - where the rod bearing sits. That side should go against the fillet on the rod bearing journal on the crank.

 

[TT5.9mag]

but I'm planning on giving Mike a call.

Mike is a wealth of good info. Do yourself a favor and go read all of his tech articles before calling. You’ll have a better understanding after doing that AND talking to him.

 

[Kern Dog]

Man, those parts are pretty aren't they? Not sure if you noticed, but there should be a more pronounced chamfer on one side of the connecting than the other - where the rod bearing sits. That side should go against the fillet on the rod bearing journal on the crank.

The aftermarket cranks often require the use of narrower rod bearings due to that rolled edge of the rod journal on the crank.

 

[James Clews]

My 410 has SRP forged pistons 5 thou below deck with .028 cometic head gasket with trick flow heads and calculates to 11.5 to 1 compression!
It has 5 speed tremec and 3.91 diff ratio!
I run premium unleaded that is 98 but in Australia we measure our fuel in the opposite to USA ( RON or MON) and I have never heard detonation in my engine and will pull cleanly from about 1000 rpm in fifth gear without complaining and I have a custom roller cam designed by Mike at B3 236.6 / 242.6 and 610 lift on a 112 lobe sep. That cam idles sweet at about 800 rpm with a slight lope but behaves really nice and gets 23 mpg on a run and makes 425 RWHP (about 540 flywheel) and runs low eleven sec qtrs in an Australian Valiant Charger!
If the engine is set up correctly it will not detonate !
It also measures 205 PSI compression on a snap on compression gauge!

 

[RBConvert]

Mike is a wealth of good info. Do yourself a favor and go read all of his tech articles before calling. You’ll have a better understanding after doing that AND talking to him.

I bookmarked his site and read all four of his articles. When I read these articles, it reminds me just how much I don't know about performance builds. I think I'm pretty knowledgeable and can hold my own in a conversation. Then I read those articles that Mike posted and I feel like I'm in school again.

 

[RBConvert]

My 410 has SRP forged pistons 5 thou below deck with .028 cometic head gasket with trick flow heads and calculates to 11.5 to 1 compression!
It has 5 speed tremec and 3.91 diff ratio!
I run premium unleaded that is 98 but in Australia we measure our fuel in the opposite to USA ( RON or MON) and I have never heard detonation in my engine and will pull cleanly from about 1000 rpm in fifth gear without complaining and I have a custom roller cam designed by Mike at B3 236.6 / 242.6 and 610 lift on a 112 lobe sep. That cam idles sweet at about 800 rpm with a slight lope but behaves really nice and gets 23 mpg on a run and makes 425 RWHP (about 540 flywheel) and runs low eleven sec qtrs in an Australian Valiant Charger!
If the engine is set up correctly it will not detonate !
It also measures 205 PSI compression on a snap on compression gauge!

Sweet build, thanks for sharing.
My build closely parallels your engine, with about a point less compression. The Hughes cam I'm honing in on is 238/242 @ 0.050" and 576/587 lift @ 1.6 ratio, with 110 LSA. I see you used B3 for your build too. One more reason for me to give Mike a call.

 

[RBConvert]

The aftermarket cranks often require the use of narrower rod bearings due to that rolled edge of the rod journal on the crank.

Yep. Hughes points out on their website that they use the narrower bearings.