340stroker engine combo help

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duster340

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playing some with numbers and parts right now my 340 is in a big need to be rebuilt and i cant realy aford to go as crazy as i would want but this is what i have planned, does it sound like it would run good and what could be impoved?

340 block 0.040 over with a pretty tall fill of hardblock about 1½-2" of waterjacket left
stock 340 rods with Arp bolts (checked out ok) bushed for floating pins
forged eagle 4"strokercrank ballanced rotating asembly
some light forged 11.5:1 compresion pistons
edlbrock performer rpm heads
holley strip dominator intake manifold
crane goldrace roller rockers
lunati rollercam looks like this Advertised Duration IN/EX: 302/310
Duration @.050 IN/EX: 273/281
Gross Valve Lift IN/EX: .640"/.640"
Lobe Sep Angle / Intake Ctr Line: 106/100
heads and bottomend ARP studed
TTI headers and 3"exhaust with straight tru mufllers
800cfm edelbrock carb
complete MSD ignition
3600rpm stall converter
3.90:1 reargears
already have the carb,block,rods,ignition,converter,reargears,roller lifters and rocker arms, headers and intake manifold:) thats basicly the only stuff that survived from the hot street 340....
any input is apreciated :headbang:
 
With a cam like that, you need more head.
 
rumblefish360 said:
With a cam like that, you need more head.
Click to expand...

was afraid that would bee the case, could i get away with these heads ported or would it be a waste? i need to be ahead of time over here since it takes some time to get parts shiped over the atlantic and i need to have the money before ordering :(
i have also looked at a slightly smaller solid roller from lunati one wish is speced out like this it looks great using desktopdyno but experience is worth alot more than a computerprogram
in desktopdyno its all done at 6000rpm but looks strong up to that point

Advertised Duration IN/EX: 285/293
Duration @ .050 IN/EX: 255/263
Gross Valve Lift IN/EX: .600"/.600"
LSA / ICL: 110/106
Valve Lash IN/EX: 016/016
RPM Range: 3200-7200
 
block fill = lack of cooling on a street driven car.
stock rods with the kind of hp you are talking (±550hp) = disaster
too much cam to my liking for a 4" stroker, unless it is strickly for the strip.
Eddys fall off after 550lift - ported maybe .575 . my suggestion is a cam in the range of 245-250*@.050 with 590/575 lift w/1.6 intake and 1.5 exhaust.
on a 108CL.
The 4" strokers don't need to spin up like the 340s to make some big numbers - probably no more than 6300max.
M2CsW - good luck.
 
Also what 388dart said. The Edel. heads are advertise to flow well up to .550 lift with a few cfm gain (2-4 or something like that.) to .575 lift.
Ported heads if done right could do the trick, but with a long duration cam and big, for the head lift, these Edelbrocks may not be up to task.
The second cam you list seems more suited for the cars weight and gear ratio, though a little heavy IMO. I'm a bit heavy with cams myself. It's also easier to get away with a 4spd manual. Which I have.

Also, with strokers, the sheer size of the new displacement, a clear 40 cubes bigger than the biggest stock small block, eats up large cams and makes them a bit more docile than they read on paper. It also shortens the RPM range because of it's size. (Stroke) Thus the reason 388 stated on not spining up high in the rpm range.

At 388 cams suggestion, in a Duster with the engine combo, I would say this would be a great mix of parts. With the heads ported out, but not race ported, will do.

You want a cam with the duration to suite driving cruise RPM or race track needs, as in RPM limit, to work in concert with every other part.
Get as much lift as the head can handle before the port stalls.
Then thats as much cam as the heads and engine combo can handle while makeing the best effort on the engine.
 
Things I'd keep: block, ignition, rockers, lifters.

Things I'd do:
leave max bore at .040 over. If it has to go bigger or be honed, replace the block.
Bush lifter bores if you havent already.
Replace main caps #1-4 with Pro Gram steel and ARP 12pt studs.
No block filler needed
No other oiling mods needed
Square deck and plate hone
Compression would be set at 11:1 with a dished piston and closed chamber head.
Things I'd buy:
Intake-If this is mostly street, I'd run the M1 single plane as first choice, RPM Air Gap as second. If it's a race engine, the 340 Victor gets the nod.
Heads- Edelbrock RPMS will feed up to 600hp with porting. Good porting. Good porting isnt cheap, but the biggest gains will be gotten from the first $500 in porting. The rest will take twice that figure to get.
Cam- Solid roller is the best, but I agree the cam you've spe'd is a little on the large side even with a 4" arm. The duration isnt bad, but you could lose 10° at .050 and the lift should be kept around .590-.600.
Rods- you should not ever consider using factory rods in an application like this. H beam Eagles would be my first choice, with expensive I beams next. SIR rods or similar dont get used in my engines.
Carburetor- 800 dry flowed(meaning about 720cfm wet) CFM is not enough. I'd be looking at a 4150 HP Holley 830 at minimum. for racing I'd bet the Victor 340 and the 950cfm HP would make the most hp.

This parts list and the right porting should yield at least 550hp on pump 93 octane fuel. really closer to 600 would be my guess.
 
i am not worried about the hardblock, it has been in the engine for many years and its actualy never running real hot, but that is with a stock stroke crank.
will drive alot on the street but i am already used to a big cam (lots bigger than the ones i have looked at now, and that was with the stock stroke) and that singleplane manifold, and what realy counts is that it is capable of some sort of idling and it need to run hard:)
realy hope the bores will clean up at .040 they hava some minor scratshes probably from whatever killed my crank:( the block has been squared earlier but i will let the machineshop have a look anyway at it
will those eagle H-beam rods clear everyting or is there alot of grinding to bee done?
thanks alot for the help:) never thougt those edelbrock heads could suport that much power
 
Once there given a kick *** porting, the could. Some companys and private peoples claim 300 cfm. Some a few cfm more. Is it worth purchasing and then porting? Or start with a better head and do minor work by compare.

Just me, I want to do a set of Mopar big port comando heads on a street machine. There 260 cfm ootb, but need to be worked on ootb before you install and run them.
Theres also that very interesting W-8 head for standard blocks. I'd look that way for some over the top street power.
 
for those H-beam rods you'll only have to notch maybe a 1/4 of an inch off the bottom of the sleeve. Its just enough room to clear the rod bolts. But if your doing it yourself, make sure there you leave enough room for heat expansion.

And I agree with what everone else has said about the cam. Strokers don't need to rev up real high. Specially with those I-beam rods. And be careful with piston to valve clearance, that could really ruin a good day.
 
I havent had a set of Commando heads pass me yet. The numbers from reliable sources I have seen are really good. But in terms of $$, a set or bare commandos is $750-800 each. Then the valves, retainers, locks, seals, springs, and cups. Now you're up to $2000, and they havent been touched yet in terms of vale job or porting. At my shop, add $200 for the Serdi valve job, and roughly $500 for a clean up, mild porting, and flow testing, and the offest rocker required (estimating this one) $400. Price after getting it flowing where you need it (290+/- cfm) and bolted on $2700. Now Edelbrock RPMS... Initial cost $1300. May need better springs, $120. Rockers, std LA, he has them. Same porting/clean up/valve job $700. Total to get them to that same 290+/- cfm and bolted on $2120.
In both cases, the heads are close to or maxxed out flow wise at 300cfm. The Commandos seem to have more cfms in the low and mid lifts than the RPMS, which on a street car should be worth some power under the curve, and a much better chamber. Whether that power gain is worth $600 is a matter of debate. I'd rather run RPMS and have decent H beams for that same money. Also, the small chambers on the Commandos will have to be taken into account. You will have serious compression trying to run a tight quench flat top piston with that head. That's an easy fix. Ross has a nice dished design piston for that.
 
Heres what Im running.

340 .030 over
H beam rods
4" eagle forged crank
12to1 Ross pistons
Edelbrock rpm heads ported
comp roller rockers 1.5
570 solid flat tappet comp cam
267/[email protected]
victor 340 intake
750 holley with pro form main body
Mopar performance ignition
TTI headers into 3" exhaust through dynomax bullets

904 trans
griner reverse valve body
8" ptc conv.
8 3/4 with 4.30s
 
Ahhhh, and the best part is in the sig;
"best so far:11.08@122mph with 1.55 60ft "

Moper, you can get more cfm out of the BP Comandos. Also, the chamber needs work, but I suspect you knew that. As a side note in addition, I can get them a kittle cheaper than what you listed them for. Not much, but your right on price vs punch.
 
great advice here, and having a summer dailydriver that will be capable of low 11second 1/4´s sounds just perfect since i dont care about fueleconomy anyway
would love a set of bigport comandos but over here the price of them complete with rockergear will be totaly unreal since i need to be ahead of time and order before i can get the parts shiped and there will be a fairly long wait, thats why i think it will bee more doable to order the edelbrock heads and make the money to port them while waiting for them ;)
that last lunati cam i speced is making power up to about 6000rpm before dropping of acording to my copy of desktopdyno wish i dont know if i can trust but it seams logical that all that extra stroke will eat up alot of the cams rpm range, but iam learning all the time..
btw never thought that this combo could be anywhere near 550-600 horsepower when i started to look at it and when my desktopdyno said so but i do trust your words on it and i want as much power as possible while keeping it fairly reliable :)
 
since it seems i would need a better and even bigger carb, would i bee a total idiot trying to run a dominator on this thing? i like doing things thats not suposed to work and a domintor carb seams like one of those things, and i know of two dominator carbs for sale for pretty nice prices and big holley carbs over here are pretty expensive but a used dominator in good condition is possible to buy for the "right price" :)
will it work on a streetcar? i´m not afraid of puting alot of time into tuning it to work if there is a chance

have a set of H beam rods brand new in a box coming tomorrow so i can give my self a nice xmas present:)
 
"For the most part" the larger the carb the better. That's not always the best idea ona car that runs on the street and at part throttle a bit. I think overall, a Dominator will make the best power and the lowest ET. I dont like DOminators on the street on anything. They are not designed for part throttle or extended idling time. IMO, if you want to run one, call up a professional carb place and have them custom build you one. Otherwise, the std 930cm HP type carbs will work really well.

Rumble, truthfully, I havent seen a set of BP Comandos. I really dont know much about what to do with them. Just looking at others' published numbers. I also tend to take a little off most published numbers, because I've found the bench I use is never as generous with the numbers as many others claim to have...lol.
 
dont think i have ever seen a used 930cfm holley for sale over here but plenty of dominators:( there is basicly no carb shops over here, wish makes it almost imposible to get one set up profesionaly, and a new 930cfm holley will cost me a small fortune..
will se what i can find until the spring! i always apreciate your help and advice but knowing that a dominator is suposed to be imposible to tune in as a street carb makes me realy tempted to try, i can always bolt on my old and reliable 800cfm edelbrock in case it wont work until i can aford one of those big std holleys ;)
 
have another litle problem with this also, cant seem to find any lightweight forged pistons for a 4.08bore 340
cant find them for a stroker and cant find them for stock stroke either, start to feel like i can just trhow this block on the pile of scrap and start colecting stamps or something instead, since i cant afort to buy both a forged stroker crank and custom forged pistons anyway.... could probably afford custom forgings for a stock stroke if i can save my old crank but my luck probably wont give me that happines anyway
 
Ross makes them by special order. Dished or flat top. Give them a shout. As I recall the last set I had were $600 with pins.
 
4.08 is an odd overbore. Thats why it's hard to find pistons.
Nice cam Len. That should put some hustle in your stuff. :tongue9:
 
rumblefish360 said:
4.08 is an odd overbore. Thats why it's hard to find pistons.
Nice cam Len. That should put some hustle in your stuff. :tongue9:
Click to expand...

yeah but it seams like anything bigger than 4.07 bore pistons are oddball pistons for a 340 :(
will have a look at those rosspistons sugested 600$ seems fair
leenweiler that cam should rock in a strokerengine that have enough head to suport it :thumbup:
i think that lunati cam that was my second choise pretty much is the biggest cam that "stocktype" heads can take, but that is just from the look of the curves in desktopdyno
thanks alot for the help so far :thumbup:
 
mikesduster said:
was that BEFORE the .040 or after?? :toothy7:
Click to expand...


Geez Mike, as I recall, it was after the assembly debacle. And after that, with the .520 cam, it pulled around 430hp and close to 500tq at the crank. It was .030 before that mess..lol.

.040 over is as big as I'd go, and I wouldnt do it without sonic testing the block first if it's for a 4" arm.
 
I'd have to agree with the Lunati. Like to dur.@ .050" with stock eddy's.
 
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