Tuesday, October 27, 2020

Engine Swap - Dart SHP based stroker!

The last time I wrote about this motor, there was still a long way to go.  Since then, a good count of parts needed to be changed.  I'll also update the progress after I got the motor home and on the stand.  I'm planning to do the engine swap this off season.  Hoping to get it done before April 2020!

I'll start off with the Probe crank - it was balanced and ready for assembly when inspection showed the thrust was way out of spec.  Basically the crank was unusable.  So we had to trash it.  The replacement is a Scat forged crank.  I'm not upset about this.

The pistons are still CP Billet forged, with Liberty rods. The bore is actually 4.155 and stroke is 3.25 making the displacement 352ci.  So its not a 347! 

Oil pan - the pan I had didn't fit the dart block and had to go with one that did.  Needed a pick up tube also.  The pan has two bungs welded in for oil return - one on each side - just in case.

The AFR 185 heads have been worked over, significantly.  They are now 210's, with bigger intake valves and brand new exhaust valves, new springs, new retainers - basically everything replaced.  The LGM shaft mount rockers are on, but didn't clear my valve covers (at first, more on that later). Needed a 12pt head stud to clear the shaft mount rails.  Head gaskets are MLS by Fel Pro. 

Cam is unchanged - FTI custom grind.  

Still have the Romac balancer and RAM billet steel flywheel.

The Trick Flow R intake lower has been port matched to the heads.


The Dyno session couldn't use my Trick Flow R intake since that is EFI.  What they had on hand was a cheap dual plane intake and a 600 carb, which definitely hurt the numbers.  The motor did make 465 HP and 440 TQ.  Not bad for being restricted.  We were shooting for 500HP and with a good intake and fuel delivery, that would have easily been achieved.

Extra:  

The motor has been home and on the engine stand for some time now.  I've sourced the alternator and power steering brackets, power steering pulley and a new power steering pump.  I've had the pulleys and brackets powder coated wrinkle black and they are mounted to the engine using the stock hardware.  The pulleys have ARP hardware, including the crank, water pump, and thermostat housing.  

I've installed Team Z 3/4 inch drop solid motor mounts.  This took some massaging on the block and mounts, but turned out awesome.  I ordered ARP bolts for the mounts too.

I had to do some grinding on the inside of the trick flow valve covers to make them fit with the shaft mount rockers.  Both valve covers were hitting the rocker stand.  Using a micrometer, I measured the thickness of where the interference was on the valve cover.  I used a die grinder with the sanding disk to clearance a little at a time.  Eventually the valve covers fit, and I only removed a couple thousandths of an inch from the covers.  I'm really excited that the valve covers fit!  They offer a ton of clearance with the R intake and look good too.  I have a stainless steel stud kit I made for the covers as well using stainless set screws and shouldered stainless nuts.  

Speaking of the heads, I also have a set of stainless header set screws, ARP 12 point stainless nuts and washers.  The headers will be BBK long tubes with 1 3/4 primaries.  I cut the ball flanges off, which will be modified for a V band clamp and custom mid pipe.  Mufflers are Gibson BM0105, and I'm deciding to go with Pypes or Flowmaster 3 inch tailpipes.  The whole exhaust will be 3 inch.  

I'll put up another post about the K member and steering rack, which is going to be a significant upgrade!




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