340/416 Stroker Kit questions?

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Thanatos340

Thanatos340

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While my 340 is down due to a wiped lobe on the cam and since I have decided that I need to do a full rebuild, Might as well go all the way and Stroke it while I am at it. This will be my first solo engine build and want to make sure I am getting the right combo. Recommendations and suggestions would be greatly appreciated.

Street/Strip weekend cruiser. Must run well on Pump Gas.
1969 340 Block (.030 over)
Lunati Cam and Lifter Kit 10200704 (276/284 Dur, 513/533 Lift)
ProComp CNC ported Aluminum Heads (Closed Chamber 68cc)
AirGap Intake
904 Street/Strip Trans (All the usual upgrades)
MSaine Custom built 3000 stall converter
3.91 Gears in the rear-end

Questions:
1. I am guessing that with most any stoker Kit, This should be 450 to 500 HP when done. Will a Cast Crank be sufficient or is a Forged setup required here?

2. Pistons? Dished or Flat Top? With Aluminum Heads is 11.3 to 1 going to be OK with Pump Gas?

3. Which Stroker Kit would you buy for this set up?

I of course want as much HP as possible. I am not building a daily driver here but do want to be able to drive it an Hour or more each way on the way on the interstate to the strip and to Meetups on the weekends.
 
Thanatos340 said:
Questions:
1. I am guessing that with most any stoker Kit, This should be 450 to 500 HP when done. Will a Cast Crank be sufficient or is a Forged setup required here?

2. Pistons? Dished or Flat Top? With Aluminum Heads is 11.3 to 1 going to be OK with Pump Gas?

3. Which Stroker Kit would you buy for this set up?

I of course want as much HP as possible. I am not building a daily driver here but do want to be able to drive it an Hour or more each way on the way on the interstate to the strip and to Meetups on the weekends.
Click to expand...

1: If you're gonna do it, may as well get a forged crank.

2: Depends on what CR you'll be shooting for. Using a flat top with -6 cc for valve reliefs (same as Diamonds with 4.070 bore), I get right around 11.3:1. Will that be OK with pump gas? With the right cam yes it will. The cam MIGHT need some overlap to achieve this. Cam manufacturers are good with knowing the voodoo behind it all and can tell you if you'll be safe with the particular cam you have. Some cams really pump up the cylinder pressure and some don't (more overlap). Give the experts a call on that one.

3: I have an Eagle kit in mine and I don't really have any complaints thus far. Callies I believe is another good one. Can't think of others off the top of my head but other members will chime in I'm sure.
 
You will exceed the 500hp level with a mild cam with the right heads. So power won;t be a problem. I like to use a smaller dished piston rather than a flat top. I think over 10.5:1 static can be a problem if you are not doing all the machining operations to ensure the quench is excellent and the same on all 8 holes. Plus - you don't need it for your level. The Scat cast cranks are the cast ones to use. I would not use an Eagle cast. Have the assembly balanced by your shop. Otherwise it's pretty much buy what you can get cheap. SIR rods will hold up, H beams are heavier but stronger. Factory rods will work but need the bores nothced to clear.
 
Thanatos340 said:
While my 340 is down due to a wiped lobe on the cam and since I have decided that I need to do a full rebuild, Might as well go all the way and Stroke it while I am at it. This will be my first solo engine build and want to make sure I am getting the right combo. Recommendations and suggestions would be greatly appreciated.

Street/Strip weekend cruiser. Must run well on Pump Gas.
1969 340 Block (.030 over)
Lunati Cam and Lifter Kit 10200704 (276/284 Dur, 513/533 Lift)
ProComp CNC ported Aluminum Heads (Closed Chamber 68cc)
AirGap Intake
904 Street/Strip Trans (All the usual upgrades)
MSaine Custom built 3000 stall converter
3.91 Gears in the rear-end

Questions:
1. I am guessing that with most any stoker Kit, This should be 450 to 500 HP when done. Will a Cast Crank be sufficient or is a Forged setup required here?

2. Pistons? Dished or Flat Top? With Aluminum Heads is 11.3 to 1 going to be OK with Pump Gas?

3. Which Stroker Kit would you buy for this set up?

I of course want as much HP as possible. I am not building a daily driver here but do want to be able to drive it an Hour or more each way on the way on the interstate to the strip and to Meetups on the weekends.
Click to expand...

1. Scat cast crank is fine and has great reputation. If you upgrade to much bigger cam or nitrous might want forged? But when you do that will your 500-525hp crank be your only bottleneck? Will you want different pistons, heads, etc.? Might just build another motor at that point? Maybe not? Things to consider.

2. I run 9.7-9.8 measured with quench and comp XE274-S in my 416. It will ping at much more than 33 degrees total with the pump 91 gas we have in California. Thats with Edelbrock 60779 "63cc" heads measured at 65cc and Scat rotating assy with ICON forged pistons.

3. We measured everything before hand and fit everything and the SCAT rotating assy I bought from Brian at IMM Engines he suggusted was spot on.
 
I suggest at least a SCAT forged crank and some good rods. 20cc dish pistons in a stroker zero decked with eddys usually runs around 10-1 or a tad higher. You didn't mention rockers. The Hughes pieces are pretty nice.
 
Good question on the Rockers. I have 3 choices sitting on the shelf right and not yet sure which to use.

1. Factory 273 Adjustable Rockers (This is what I was running before)
2. Pro-Comp Aluminum Roller Tips (Seems many people are afraid of these but they came with the heads)
3. A set of NOS (Been on the shelf for over 15 years) Speed-pro aluminum roller tips. (Problem with these is I don't have the Spacers for them, I found the correct part number for the spacers but have not found anyone that can get them)

I would love to buy some Hughes or other high dollar rockers but just don't see the HP to Dollar return on those.
 
I'd save money and run 273 rockers with that cam. Make sure they clear the valve spring and retainer.
 
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