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Building a 340 - Various Buildup Questions

Posted By: Erik

Building a 340 - Various Buildup Questions - 05/19/08 05:19 PM

I heard back from my machine shop today and the 340 block I dropped off is ready for the stroker build. I saw a couple of different kits from Mancini for about 2K. My question is should I go internally or externally balanced? This is going in my '68 'cuda w/ had a 4 spd tranny.

Also, any recommendation on heads? I was leaning toward the Edelbrock 340 heads using something like a Comp XE280 cam.

I am building a nice street motor that may see a pass or two down the track so I don't want to go too radical.

Thanks!
Posted By: 69Cuda340S

Re: Building a 416 Stroker - Kit question - 05/19/08 05:27 PM

Don't get the Edelbrock "340" heads. Get the Edelbrock closed chamber 63cc LA engine heads and build a quench combustion chamber engine. I am building a 414" (340 block .020" over) stroker. I ordered the Scat cast crank kit with the KB745 forged step dish pistons:

1-98013BI

It comes internally balanced and Summit's price right now is $1279 plus $11 handling and free shipping. Scat says they guarantee the bearing clearances and balance. Mine will be getting checked out by a local shop. Should be few more weeks before it arrives.

I am building mine as a street engine for pump gas.
Posted By: HotRodDave

Re: Building a 416 Stroker - Kit question - 05/19/08 06:42 PM

Dan at performance only racing can get you a real good deal on the same kit plus you will be suporting a moparts member and someone who knows about mopars.
Posted By: BobR

Re: Building a 416 Stroker - Kit question - 05/19/08 07:55 PM

Quote:

I heard back from my machine shop today and the 340 block I dropped off is ready for the stroker build. I saw a couple of different kits from Mancini for about 2K. My question is should I go internally or externally balanced? This is going in my '68 'cuda w/ had a 4 spd tranny.

Also, any recommendation on heads? I was leaning toward the Edelbrock 340 heads using something like a Comp XE280 cam.

I am building a nice street motor that may see a pass or two down the track so I don't want to go too radical.

Thanks!




I used the Mancini kit for my 416. It is a high quality kit that uses a Callies crank. I got the one that was already balanced. I also have Eddy heads that were ported by RyanJ at Shady Dell speedshop. It's agreat combo that's hard to beat. I have a small solid street roller and 11.5-1 compression and my motor made about 540 HP with a Perf RPM Airgap/950 Holley and just under 500 with a six pak. -Bob
Posted By: W5Duster436

Re: Building a 416 Stroker - Kit question - 05/19/08 08:00 PM

Quote:


I used the Mancini kit for my 416. It is a high quality kit that uses a Callies crank. I got the one that was already balanced. I also have Eddy heads that were ported by RyanJ at Shady Dell speedshop. It's agreat combo that's hard to beat. I have a small solid street roller and 11.5-1 compression and my motor made about 540 HP with a Perf RPM Airgap/950 Holley and just under 500 with a six pak. -Bob



Excellent!
Posted By: JohnRR

Re: Building a 416 Stroker - Kit question - 05/19/08 08:13 PM

erik , do an internal balance engine .
Posted By: Erik

Re: Building a 416 Stroker - Kit question - 05/19/08 08:18 PM

Quote:

erik , do an internal balance engine .



Thanks. I am going to discuss my options w/ my machine shop tomorrow.
Posted By: Erik

Re: Building a 416 Stroker - Kit question - 05/20/08 05:24 PM

After a discussion w/ my machine shop, this is what we decided to do:

Bore the block to 30 over and deck it
Use the stock forged 340 crank I already have
new Eagle rods
new TRW pistons
Edelbrock 340 heads
Edelbrock Performer RPM Airgap intake
Comp Cam 280 mechanical cam/lifters
750-800 cfm carb (undecided on type)
10.5:1 copression ratio

He feels I should be able to get 400 - 450 hp out of it.

What do you all think?

Posted By: BobR

Re: Building a 416 Stroker - Kit question - 05/20/08 05:27 PM

"He feels I should be able to get 400 - 450 hp out of it.

What do you all think?"


Closer to 400 than 450. -Bob
Posted By: Erik

Re: Building a 416 Stroker - Kit question - 05/20/08 06:11 PM

400 is still good for me.

He is trying to push me to a mechanical cam. Since the car will only see occasional passes, would a hydraulic setup be better for my needs?
Posted By: loco340cuda

Re: Building a 416 Stroker - Kit question - 05/20/08 06:15 PM

Erik, I would go stroker. When I had my 417 built I told the builder I wanted a fun street motor and something that was going to be reliable. Here is what he built me:

340 block (0.035 over)
Eagle 4" crank
reconditioned stock rods
custom forged venolia pistons
9.5:1 compression (very pump friendly)
stock 'X' heads with 2.02 valves. (heads were cleaned up and good valve job done)
Mopar Performance 484 cam (241int/241ext, .484int/.484ext 108lsa)
Edelbrock Airgap intake
Holley 770 vacuum Secondary Street Avenger Carb
FBO ignition system
FBO curved distributor

On a chassis dyno the car made 375 peak RWHP and 484 peak RWTQ. At the flywheel the peak numbers are 420HP and 537HP respectively.

If you go through my build you can see that it is quite conservative. If I were to swap the heads for some Edelbrocks and put another cam with higher lift I could squeeze a fair amount more HP out of it but for my purposes this engine is good enough for the street and fun to drive as well as reliable. It also has a nice mean idle sound to it.

Unless there is a huge cost difference go stroker.
Posted By: HotRodDave

Re: Building a 416 Stroker - Kit question - 05/20/08 06:21 PM

Sounds like a chevyguy building a mopar

Eagle rods are junk compared to an equivalant SCAT rod. Also for the pistons there are way better choices out there for about the same money. TRW pistons are very heavy 40 year old desighns and that cam is really going to want to turn some rpm. I would say at least 6500-7000 shift points. The SCAT rods are mede of 4340 steel instead of 5340 in the eagle, the scats also use cap screws instead of a nut and bolt like eagles and stock rods. I am not sure about the eagles but I know the SCAT rods use arp bolts and the are a lot less likely to need resizeing.

I would get a flat top piston and run the closed chamber eddy heads. That way you can take advantage of quench and not get a bunch of crevice volume. The price is about the same so why not do it better?

I do think it will make closer to 450 with good machine work though. Good cam and intake choice. Either way will make similar HP but durability will be way better and it will rev a lot quicker witch makes it feel more powerfull .

The differance in the stroker kits and what you are doing is almost none and will make you very very happy!
Posted By: Erik

Re: Building a 416 Stroker - Kit question - 05/20/08 06:31 PM

Quote:

Sounds like a chevyguy building a mopar

Eagle rods are junk compared to an equivalant SCAT rod. Also for the pistons there are way better choices out there for about the same money. TRW pistons are very heavy 40 year old desighns and that cam is really going to want to turn some rpm. I would say at least 6500-7000 shift points. The SCAT rods are mede of 4340 steel instead of 5340 in the eagle, the scats also use cap screws instead of a nut and bolt like eagles and stock rods. I am not sure about the eagles but I know the SCAT rods use arp bolts and the are a lot less likely to need resizeing.

I would get a flat top piston and run the closed chamber eddy heads. That way you can take advantage of quench and not get a bunch of crevice volume. The price is about the same so why not do it better?

I do think it will make closer to 450 with good machine work though. Good cam and intake choice. Either way will make similar HP but durability will be way better and it will rev a lot quicker witch makes it feel more powerfull .

The differance in the stroker kits and what you are doing is almost none and will make you very very happy!



Funny you say that. He feels that the Scat products are garbage. He helped me build the stock 340 I had in my Chally 'vert. and is rally a Mopar guy trying to make a living in a Chevy world......

So you are saying I should go for the standard 318-360 RPM heads and not the 340 heads? We are running flat top pistons. What type of piston do recommend over the TRWs?
Posted By: Erik

Re: Building a 416 Stroker - Kit question - 05/21/08 12:22 PM

Posted By: 69Cuda340S

Re: Building a 416 Stroker - Kit question - 05/21/08 12:53 PM

Quote:

So you are saying I should go for the standard 318-360 RPM heads and not the 340 heads?



Yes, get the closed chamber 63cc heads and get a piston that sits at zero deck for a quench combustion chamber.
Posted By: AdamR

Re: Building a 416 Stroker - Kit question - 05/21/08 01:02 PM

Ther 340 will still make good hp but the torque wont be any were near as good as it would be be with the 4" arm.
Posted By: ScottSmith_Harms

Re: Building a 416 Stroker - Kit question - 05/21/08 01:44 PM

I'd go stroker for sure for a street engine, stock stroke engines can make good power on paper and on the dyno (especially in the upper RPM ranges) but in real world street driving low RPM torque is where the fun is, strokers feel like a big blocks off idle, a joy to drive on the street. I've done allot of research on cranks recently, I agree with many of the above posts, go internally balanced, buy the best crank and rods you can afford, and use the lightest pistons you can afford (I like Scat or Callies cranks, Scat, Manley($), or Carillo($$$) rods, and Diamond pistons). Air gap intake with a good carb of choice.

Hydraulic cams are also great for street driving, same reason, zero valve adjustments, similar power, especially in the lower RPM ranges. A solid or roller cam will ultimately allow higher RPMs and more power, but on the street you'll rarely need either.

I don't see the need for you to buy EB heads if you want to make around 450HP, a good valve job and mild port work on some X or J heads will get you there with the right combo, plus iron heads make more power than aluminum all things being equal. If you want some free HP from iron heads the 308 heads are awesome, you can approach W2 numbers with them with very little work. Aluminum has it's advantages (ease of porting and easier to repair if they get hurt, etc.) but for a budget build iron heads are pretty hard to beat.

Posted By: dogdays

Re: Building a 416 Stroker - Kit question - 05/21/08 01:49 PM

Scat rods are better than Eagle rods, especially the SIR.

DO NOT use the 340 Edelbrock head! Use the closed chamber Edelbrock head. The only thing the 340 head will get you is lack of squish. Build the engine for pistons at deck level (zero deck).

TRW pistons aren't sold any more. They are now called Speed-Pro. They are heavy, 720 grams without the pin. This is a bigblock piston weight.

This is exactly the wrong piston to use in an engine built for acceleration.

You should be able to find a lightweight custom forging that weighs around 200 grams less and doesn't cost a bunch more. If you are not building a stroker then the 340 needs to rev to make power. Lightening up the pistons allows quicker engine acceleration and puts less stress on the reciprocating parts, bearings and crankshaft.

Sounds to me that your engine guy is stuck in a time warp (without Susan Sarandon prancing around).

R.
Posted By: 69Cuda340S

Re: Building a 416 Stroker - Kit question - 05/21/08 01:54 PM

Start running some cost numbers and you will find it just doesn't make sense not to build a stroker. Especially if you can afford the Edelbrock heads.
Posted By: Erik

Re: Building a 416 Stroker - Kit question - 05/21/08 02:07 PM

Thanks for the replies everyone!

I already have a good 340 forged crank, so why spend $$ on a new crank? That is why I am not going the stroker route.

For the build, the block and the crank are the only parts I have to start with. I will look into different pistons & rods. As far as heads go, I don't have any right now so that is why I would go the Edelbrock route. If I could find a nice set of X heads, I would consider them also. I don't see too many of them around.

I think I'll stick w/ a hydraulic cam. I don't want to have to keep adjusting it. What do you think of the Comp Cam Magnum 280?
Posted By: ScottSmith_Harms

Re: Building a 416 Stroker - Kit question - 05/21/08 02:12 PM

Erik, don't drink the "X Heads are the best" Koolaid, O,J,Z, Blank, etc. any "915" casting 340/360 heads can flow just as well, they are nearly identical in every way to X heads and have just as much potential.
Posted By: 69Cuda340S

Re: Building a 416 Stroker - Kit question - 05/21/08 02:15 PM

I'd sell that 340 crank instead of paying to have it reconditioned. Then buy a complete 4" internally balanced rotating assembly. Again, run some cost numbers.
Posted By: ScottSmith_Harms

Re: Building a 416 Stroker - Kit question - 05/21/08 02:19 PM

Quote:

I'd sell that 340 crank instead of paying to have it reconditioned. Then buy a complete 4" internally balanced rotating assembly. Again, run some cost numbers.





Save some money, bypass the EB heads and buy a stroker crank, money will be better spent on the added stroke than any gain the heads MIGHT offer over a nice set of iron heads that can be purchased and put together for half the cost of EB's.
Posted By: Erik

Re: Building a 416 Stroker - Kit question - 05/21/08 02:47 PM

OK - I hear you. I can certainly save $$ going the cast iron head route.

I am still not sold on the stroker kit. I have seen prices that range from $1000 to $3500. My builder talked about an Eagle kit. Any recommendations there? I see Mancini has a Callies kit for 2K. I would like to stay w/ a forged crank.

When I price out (in Summit catalog) rods/pistons/bearings/rings I come up below $1000.

The only way I see a stroker kit being cost competitive is if I switch to a cast crank. Would a cast crank be bad for my application? I would think not. Maybe I should reconsider this forged crank thing.....
Posted By: 69Cuda340S

Re: Building a 416 Stroker - Kit question - 05/21/08 03:34 PM

I am going with the Scat cast crank rotating assembly and the kit was $1279 from summit with forged pistons, internally balance, with rings and bearings. It is cast steel and will live a long time at 500 hp or less type applications. Plenty of people out there running low 11s with cast stroker cranks in there small blocks. Go with ARP main studs too.
Posted By: ScottSmith_Harms

Re: Building a 416 Stroker - Kit question - 05/21/08 03:37 PM

Nothing wrong with a cast crank for less than 500HP. I would always prefer a forged crank but it's not the end of the world if you can't afford one. One reason you see higher prices with a kit is because most include final machining, balancing, clearancing, etc. You typically need to have that done when you combine off the shelf parts, so, even though the kits "seem" more expensive, in the long run they can actually be cheaper.
Posted By: 69Cuda340S

Re: Building a 416 Stroker - Kit question - 05/21/08 03:45 PM

Look at the weight of the cranks and you will see the cast cranks are lighter which lets the motor rev quicker. I wouldn't go forged unless you are going over 500 hp or are going to rev it over 6000 rpm frequently.
Posted By: Erik

Re: Building a 416 Stroker - Kit question - 05/21/08 03:47 PM

Thanks for the info. I found a set of redone J heads for $800. If I picked these up, would I need to get them ported?
Posted By: 73swinger

Re: Building a 416 Stroker - Kit question - 05/21/08 03:55 PM

Erik, if you do go factory crank and all, the KB hyperutetic cast pistons work well, and are lighter.
340 E heads will be needed if the KBR243 pistons are used.
Thats my combo and it will work on pump gas (mid to premium).
but it is kind of old school. That said, if I was to do over, I would go to a 4" internal balance.

good luck, and if you do go factory route, you can PM me for more info.
Posted By: 69Cuda340S

Re: Building a 416 Stroker - Kit question - 05/21/08 03:59 PM

Quote:

Thanks for the info. I found a set of redone J heads for $800. If I picked these up, would I need to get them ported?



Have you looked at the EQ heads? They are based on Magnum heads, closed chamber, flow way better then X or J heads, and have a thick casting so they could be ported out. If you are on a budget those would work well out of the box and later on you could port them out. A brand new pair complete is less then those J heads:

http://www.aaeq.net/Enginequest/Cylinder_heads/performance

Or with some port work just a little more then the J heads:

http://www.hughesengines.com/partDetail.asp?partID=11901&eTypeID=1

If I was going to go with iron heads those are what I would use.
Posted By: HotRodDave

Re: Building a 416 Stroker - Kit question - 05/21/08 04:26 PM

A complete SCAT kit internally balanced and ready to drop in is $1279 I had another board member tell me he can sell them to me for that price. It has forged pistons I beam rods and a cast crank. Comes with rings and bearings.

Your 340 if you buy rods SCAT I beams or eagle crap $275, forged pistons $400 Balance crank $150 rings and bearings $200 you are over $1000, you can sell your 340 crank for $150 all day long and make up all the differance.

Unless you are class limited it makes no sense.

Also don't pay $800 for iron heads unless they are fully ported by a pro with stainless valves and good springs. If they are just plain old rebuilt no more than $300. I do agree about the EQ heads being a real good value. Clearwatercylinderhead on e-bay sells some with 2.02 valves and good springs for $475each

http://cgi.ebay.com/ebaymotors/NEW-EQ-MO...emZ370052320832

They should make as much power (mabey a few more) as eddys and save almost $500 If they make 10 more HP they will take care of the weight differance.
Posted By: dogdays

Re: Building a 416 Stroker - Kit question - 05/21/08 04:37 PM

Redone stock heads for $800? Are you kidding? Lousy combustion chamber, old, heavy, don't flow with the Edelbrocks. I think it's a step backwards. There aren't any OEM heads that flow worth a crap. If you want cast iron go with W-2s.

Look at www.shadydellspeedshop.com to get some info.

You can build as big an engine as you like but the heads will determine the horsepower limit.

R.
Posted By: 69Cuda340S

Re: Building a 416 Stroker - Kit question - 05/21/08 05:13 PM

Quote:

A complete SCAT kit internally balanced and ready to drop in is $1279 I had another board member tell me he can sell them to me for that price. It has forged pistons I beam rods and a cast crank. Comes with rings and bearings.



And you don't have to clearance the block either with that kit.
Posted By: Erik

Re: Building a 416 Stroker - Kit question - 05/21/08 05:14 PM

I am not familiar w/ the EQ heads - I'll look at them. I also thought $800 was a bit steep for J heads - hence I didn't get them.

I have a call into the machine shop to talk cost of what we talked about yesterday as compared to a cast stroker kit.
Posted By: patrick

Re: Building a 416 Stroker - Kit question - 05/21/08 05:18 PM

Quote:

A complete SCAT kit internally balanced and ready to drop in is $1279 I had another board member tell me he can sell them to me for that price. It has forged pistons I beam rods and a cast crank. Comes with rings and bearings.

Your 340 if you buy rods SCAT I beams or eagle crap $275, forged pistons $400 Balance crank $150 rings and bearings $200 you are over $1000, you can sell your 340 crank for $150 all day long and make up all the differance.

Unless you are class limited it makes no sense.

Also don't pay $800 for iron heads unless they are fully ported by a pro with stainless valves and good springs. If they are just plain old rebuilt no more than $300. I do agree about the EQ heads being a real good value. Clearwatercylinderhead on e-bay sells some with 2.02 valves and good springs for $475each

http://cgi.ebay.com/ebaymotors/NEW-EQ-MO...emZ370052320832

They should make as much power (mabey a few more) as eddys and save almost $500 If they make 10 more HP they will take care of the weight differance.



call these guys http://www.cmengines.com/

they quoted me $425 for EQ 318B's, using chevy valves .1" longer than stock and springs good for .550" lift with a hydraulic roller cam...
Posted By: Erik

Re: Building a 340 - Various Buildup Questions - 05/21/08 06:52 PM

I found another set of 340 J heads that have been redone/pocketed/ported/etc for $650 here on Moparts. That sounds like a better price.
Posted By: ScottSmith_Harms

Re: Building a 340 - Various Buildup Questions - 05/21/08 07:04 PM

Quote:

I found another set of 340 J heads that have been redone/pocketed/ported/etc for $650 here on Moparts. That sounds like a better price.



Yes, $650.00 for a pocket ported set of fresh J heads with a good set of valves and springs sounds about right.

Keep in mind that your short block is the foundation of your engine, putting money in your short block now is the way to go, you won't see a bigger gain from a street small block than building a stroker. If you ever want step up to
a better flowing set of heads down the road it's an easy bolt on change, nothing as involved as changing the stroke of your engine.

Build the stroker low end now, use whatever the best set of heads and other accessories that you can afford, and make upgrades later as budget allows. Don't forget, a good set of J (or any 915 heads) will make very decent power, they just don't make as much as some other choices that can cost allot more.
Posted By: 69Cuda340S

Re: Building a 340 - Various Buildup Questions - 05/21/08 07:18 PM

The Scat kit I am getting comes with KB745 forged step dish pistons:

http://kb-silvolite.com/forged.php?action=details&P_id=325

If you run them with open chamber J heads your compression will be about 9.4-9.5 to 1 which will work good for pump gas. Get the block machined so the quench pad is at zero deck and the dish portion is below deck. Then later you could switch to Edelbrock closed chamber heads for 10:1 compression pump gas motor.

Like Harms said, if the budget is tight put the money in the short block so that high flow closed chamber heads can be put on later when more funds become available.
Posted By: Erik

Re: Building a 340 - Various Buildup Questions - 05/21/08 07:42 PM

OK - you guys talked me into it & I just got off the phone w/ the machine shop. I will build the 416 stroker and start w/ a set of ported stock heads.

I now need to decide on the kit for my build. I mentioned Scat again and he didn't seem to put up too much of a fight. He talked about having to do pan rail clearance w/ the kits he has used before. Am I correct in that the Scat rods don't need to have the rail cleared?
Posted By: 69Cuda340S

Re: Building a 340 - Various Buildup Questions - 05/21/08 08:06 PM

Quote:

OK - you guys talked me into it & I just got off the phone w/ the machine shop. I will build the 416 stroker and start w/ a set of ported stock heads.

I now need to decide on the kit for my build. I mentioned Scat again and he didn't seem to put up too much of a fight. He talked about having to do pan rail clearance w/ the kits he has used before. Am I correct in that the Scat rods don't need to have the rail cleared?



Its not a chevy or a ford so no pan rail clearance is needed. Typically on a SB mopar you will need to notch the bottom of the cylinders if you use stock rods and some other rods. The Scat I-beam rods, which are forged, use ARP cap screws which are real low profile so no cylinder bore notching is needed. So the answer is no notching is needed anywhere but check it anyway.

I called Scat a few weeks back and they tell me they guaranty the bearing clearances and balance of their kits. I am going pay more to have my engine shop go over all of it and double check it anyway. They have an online catalog:

http://www.scatenterprises.com/
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