Mopar Muscle Slant Six Build

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Actually, "they" (Mopar Muscle) didn't build it, they followed along as Romeo Furio paid for it and Mopar Engines West built it. Romeo posts on slantsix.org from time to time, and answered lots of detailed questions about the build over there.

IMHO, Mopar Muscle isn't very slant-friendly.

VM
 
thanks for clearing that up. Hey vynn23, do you actually have a long rod slant? That is 198 rods in a 225 right? If so, could you tell me more about it? thanks.
 
Yep! I drive it to work everyday, unless it rains. Like you said, it uses the 198 rods (I bought my set from Doug Dutra), and six KB hyper pistons from the 2.2 turbo engine (also went in with Doug on a "group buy" for pistons — we bought 3 sets, and split 'em in half). Yes, I brushed with greatness on this engine build! :) My compression estimate came out to around 9.3:1.

Nothing much special about the engine otherwise — Super Six, Dutra Duals into 2" pipes all the way back, HEI ignition, Erson 270 cam (I think I got the last one from Summit before they went out of production, but Erson has since worked with Doug to produce some new grinds), and a 2600 stall converter from Edge. Still have a stock head (with upgraded springs) and the 2.76's in the 7 1/4 out back, but even so, it's a strong engine to me (but I may have low standards!).

It's got a couple thousand miles on it so far, and I've still got some tuning to do (once it starts to cool off a bit here in Tejas). Pulls 16-17 mpg in my daily commute, about 60/40 Highway/City. My future plans are/were a big valve ported head from Mike Jeffries, a T-5 tranny swap, an 8 3/4 rear with a decent ratio, and MPFI, but the Swinger was involved in an accident last Friday. It's still perfectly driveable, but the passenger side door and door frame are screwed, probably beyond (practical) repair. So, I may end up looking for another car to drop the drivetrain in.

Lemme know if you have any questions!

VM
 
That sounds awesome. So the long rod conversion bumps up the compression. Is that all you did to get your 9.3:1? I have been thinkin of shaving the head. Would you do one or the other or both? thanks for the info. Sorry to hear about the Dart.
 
Actually, milling the cylinder head and/or block is the easiest way to increase compression (aside from custom pistons). For the benefits of the long rod engine, I'll quote SlantSixDan over on .org when the subject came up in a thread last year:

"No, this is nothing to do with compression ratio, and the lighter piston weight mentioned by 70Valiant is only a side benefit. The real benefit to the longer rods is a more favourable “rod ratio” (properly: rod:stroke ratio) which means less sideloading of the piston against the bore (=reduced friction and bearing stress), and longer piston dwell time at TDC (=better resistance to detonation) and at BDC (=better cylinder scavenging)."

So, according to those who know a LOT more about slants than I do, there were several benefits to going with the long rod. I decided I wanted to focus on getting a good short block put together while I had the opportunity, because upgrading the cylinder head and other upgrades later on wouldn't require that I pull the engine.

If I were building another slant, I'd likely mill the head for compression and the block just enough to square it. That way, if you ever need to REDUCE compression (say you get the bug to use forced induction — hey, you never know, these engines are addictive!), you can just swap heads.

I'd build a good foundation for any future upgrades by using ARP main studs and rod bolts and getting the mains align-honed if necessary (mine needed it after the ARP main studs were installed). That way it's rock solid, even if you leave the engine stock.

One big thing that nobody warned me about: Either get an oil pump blueprinted by Doug Dutra (don't know how much he charges), or have the drive gear on the pump you use tack-welded to the pump shaft (my local muffler shop did it for free). Both Melling and Sealed Power oil pumps have gone to interference-fit gears, as I found out. My pump went south on my new engine just AFTER break-in, when I thought all was safe. If I hadn't installed a mechanical oil pressure gauge... <whew!>

Best of luck! I'm far from a slant expert, but lemme know if I can help!
 
You've been a great help so far. Thanks! So the money spent on a long rod conversion would better be used on shaving the head? The only thing I am thinkin about is i am able to put the new rods/pistons in whereas I would have to pay someone (how much ballpark?) to shave the head.
So the shaft just spins inside the gear and it doesnt pump? Good thing to know! thanks again.
 
That sure seem like a of money to invest in our engines. I have heard that the small block valve springs & retainers will work on ours any truth.
 
If i have read correctly i believe anything over a .460 or so lift will require stiffer springs and some notching on the pistons. Look up slant six mods on your home page & watch for slant 6 .org. Lots of info.
 
The best valve spring to use for most cams, if you don't buy a cam with a complete kit, is the 340 with damper. Those springs on e-bay, are slightly weaker then the 340 spring, if I remember corectly. Contact the seller and ask. As for notching pistons, almost any cam bigger then 265 dur and .430 lift will require notching on a 170 motor, if the head is milled for compression. A 225 motor is usually OK up to about .500 lift, but it depends on the amout of head/deck milling. Keep in mind the old saying measure twice, cut once. With piston to valve clearence it is measure twice, blow up none.
 
I have run my long rod motor with .558" lift, 300* duration, with no valve nothches. KB 2.2 turbo pistons, 198 rods, standard deck, head cut .010", small block Ford valves.

340 springs are good to .525" lift or so.

Car has been 12.00@110 on a 150 shot of hose.
 
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