340 or 360 for hp

[moparleo]

Excellent prices. Does your brother work there?

 

[btceng]

Thanks for the feedback. I only know of two shops locally and this is the one that all the racers use. I gave a deposit on the work today. I hope all goes well. I really cant afford to lose on this thing again. My current plan is to have the machining done and assemble it myself. I think that I will go ahead with the 4" stroke and go all the way. The longer stroke should lower the rpms and in theory reduce wear and tear. I think I have it figured at a 422 cube. Sound right? I have a set of big valve j heads that have comp springs and have been ported and smoothed out a bit. Should breathe well if I get the intake, carburetor, cam, and exhaust right.

 

[moparleo]

Is this still the 340 that needs to be bored .060 and has the cracked pistons ?

 

[btceng]

It is one and the same. Sonic checked and inspected. I guess you can say going for broke. Finding the 4.100" pistons is not easy. Found a forged set of Diamonds for a great deal of $379 on a clearance. Also, would you use the Mopar Perf. cast crank or someone else's?

 

[moparleo]

I am assuming that you already have the cast crankshaft. The stock crank is very strong and is ok as long as you don't try to rev this thing past 6k all the time. Just have the standard checks for cracks, straightness, full radius fillet the journals, Chamfer the oil holes, polish only unless there are scratches or grooves on the bearing surfaces. Cast cranks are externally balanced, so you need to use only a damper, flywheel or torque convertor designed for the cast crank. Have the total rotating assembly balanced either way. The same preperatiuon should be done for both cast and forged crankshafts except for the external balance.
Give all your parts to the machine shop before the final honing and balancing.

 

[btceng]

Lost out on the pistons. Anyone use the KB hypers? They seem to be the next best option. The Diamond forged are near the $700 mark. Got an Eagle cast 4" crank. Will be using a Melling pump, Clevite bearings, and Molly rings. Have a windage tray and will need a new pan. Refurbishing stock rods.

The stock cast crank is .010 under and has been polished before I decided on the stroker . Anyone need one? Recommend a camshaft? Got 2.02 heads with Comp springs but want to run pump gas. Figuring on a 9:1 final.

 

[Chryco Psycho]

If it was my engine there is no way I would risk a $4-6000 engine saving $2-300 & using a cheap hyper piston but that is just me .

 

[moparleo]

:eusa_think:I was just thinking. Looking back on these posts, I have seen full nut & bolt rotisserie restorations done in less time :clock:than you have spent deciding on what to do for a motor. Have you Really decided what you are going to do yet? I want to see this thing come to life.:3gears:

 

[btceng]

I wish that I had both the time and money to do the thing in "other's" time frame, not to mention the experience. It takes a while doing it an hour at a time and a few nights a week. AND, judging by some posts here, I'm probably on schedule at only 1 1/2 years into it. I hope to have the body in epoxy by weeks end but that's depending on the weather, as I have neither a paint booth or multi-stall shop. Just yesterday my son expressed the same concern as I spent nearly 2 hours sanding the rocker panel while laying on a creeper.

This engine rebuild is the most expensive decision that I have undergone since purchasing the car. I need you guys to help me get it right.

 

[Cranky]

You'll have no problem with that Eagle cast crank turning more than 6k and the KB hyper pistons will also work just fine so long as the ring end gaps are followed to the 't' according to KB's specs. Yes, they are not as good as forged but are better than stockers and I know several who are running low 10's with them.

 

[moparleo]

Just a little bit of sarcasm.
Here is some of my advice . Decide on what your ultimate goals are. Do you want all out torque ? What RPM range do you expect peak torque at ? What kind of carburetion are looking to run. Single 4 BBL.? Six Pack? Fuel injection? Turbo ? Blower ? Low speed street driving or Hi-way speeds. crank,rods,pistons? Ignition ? It really gets confusing on what to do. Sit sown with your machinist/engine builder and decide on some real world goals. Come up with a plan, a blue print of how you plan to do it. Come up with an inventory of all the parts you have now. If they don't fit with your plan, you can sell them for money to go towards your build. How much maintenance are you willing to do to maintain your engine. Rings that seat quick but don't last a long time. Adjustable rockers that require periodic adjustments. Etc... Know your skill level. Just because you can hammer a nail doesn't mean you can build a house. Make a decision. Commit to your project and don't keep second guessing yourself. Build something. The worst decision is no decision. Lets get this party started ! Keep your goals simple. You can always upgrade items as the money becomes available.

 

[btceng]

All great advice. Here's what I have thus far. Engine block being bored .060 over after being sonic checked. New cam bearings, a little clearancing, reconditioning stock rods, new Scat 4" crank, new Shannon's forged dish pistons, Melling pump, Clevite bearings, Moly rings, ported J heads with 2.02 intakes, stock 360 dual plane, and Edelbrock 600 cfm, but looking for a 750.

My goal is a street car, no racing, and a cool sound with the ability to back it up if necessary. I'll probably be installing a 3.23 or 3.55 ring and pinion. The torque appeals to me and the fun factor.

 

[moparleo]

Good build habits

Great. Make yourself a note book with all of the parts and clearances used for this engine. All engine builders keep notebooks on all the engines they build. There are many advantages to doing this. By having all the engines specs you can duplicate the exact engine if needed . In case of a part failure in the future( it happens), you can just look up the specs for that part or parts and not have to do everything over again. Be able to rebalance the new part to match the rest of the engine parts etc... Be able to go back if you try a different cam, or heads or whatever and it you don't like the results.The best analogy I can think of is a cook book:downtown: with all your favorite recipes. You try different ingredients or portions and come up with your own custom recipe.
:wave: Give your machinist before he final hones the cylinders all of the reciprocating parts to final fit and balance. Very important things if you want to get max results. Save money when it makes sense but don't cheapout on the important stuff when you do anything for your own car. A good recipe will use the best, freshest ingredients for the best result.
Be a chef , not a short order cook.:nike:

 

[Chryco Psycho]

if the block cab be bored to .020 or.030 over I would recommend it , going to .060 for no other reason than CI makes no sense , the cyl wall can get too thin , i would choose to lose 3-4 ci & retain as much wall thickness as possible .

 

[moparleo]

I agree about the overbored cylinders. We talked about that in the beginning of this thread.

 

[btceng]

I would agree to that as well, obviously, but the block was already bored .040 at the start of this latest rebuild. The machining is done and I am currently waiting on a 4 " balanced rotating assembly from Scat.It will be using the 9000 series cast crank, forged I beams, and Autotec forged dishes at -18.5 CC. This combo at the 9.584 deck height figures for a 9.5:1 car with 70cc heads. That is if we figured right.

Finding 4.100 pistons for a 4" stroke is a challenge. These are having to be custom made but Autotec doesn't charge extra for a custom piston. I sure hope that this works out because I'm really deep into my pocket at this point. Moparleo, you'll be disappointed, as will I, that this will continue for a while because they (Scat) have given a delivery date of late May.

I'll start a new thread on the build then. In the meanwhile, I am continuing the body. All epoxied now and waiting on a new trunk floor and lower quarter patch panel.

Thanks for the continued feedback.