large port commando heads

-
D

duster340

street racer
Joined
Mar 13, 2005
Messages
2,045
Reaction score
6
Location
sweden
after lots of thinking and money saving i have decided that the mopar performance largeport comando heads seem to bee the best cylinder heads for my engine but the mopar performance catalog is not realy that good and there webpage dont help me much on some of this stuf

i know i need diferent rockers i almost think i could get away with just buying new intake rockers since i currently have crane goldrace rollerrockers and crane sells the ofset intake rockers individualy but will the shafts need to be replaced?

i know i will need rockershaft stands so i dont realy know if that also will result in new puchrods and lifters do these heads oil thru the head or thru the pushrods? (will change the pushrods anyway)

will my holley stripdominator intake manifold fit ? ( stock smallblock bolt and intake port configuration)

headers will fit because port location and shape is stock as far as i can tell

and how about valve lengths? will i need stock 340 lenght or W2 long valves?

well these are some quesstions i have right know i gues i have forgoten something let mee know if there is anything more i should know about these heads and how to make them work properly on one hot street 340..

thanks

edit: forgot to ask about valve lengths
 
Duster340,
The shafts are different and the rockers are offset .485 on the intake side only, you'll need .180 offset shafts for the spacer blocks. The pushrod lenghts will have to be determine due to the deck heights and head heights, the standard intakes work as the head is based off of a old style steel and has the W-2, W-5 exhaust bolt pattern. The oiling comes through the head as the old style, as for the valve lenght this is up to you and what you want. I would consider this a Race only head as it has 190 ccs from the factory and replaced the W-5 heads with alot better chambers.
If your looking to drive this head on the street than I would suggest the 177 cc head. The 177 cc head has cast in rocker stands and takes the stock shafts and rockers and valve lenghts, they would save you about $1000.00 in extra parts that the 190's would have to have. Keep in mind that the stock iron heads are only 150-153 ccs from the factory, so this is alot larger than stock.
 
BJR Racing,

i thought these heads also had the stock boltpatern on the exhaust, but maybee i where wrong :(
reason i am looking for the bigger heads are that this engine is already so week at low rpm and on the edge of what most people would call a streetengine
its a 11:1 compression engine with a solid rollercam that makes power in the 4500-7500rpm range
for now it looked real good with the smaller chambers to gain some more compresion and i thought dose big ports could help me later when i build this thing into a stroker wish i forgot to write about :( because i thought about buying a real good set of heads first and use for one (the next) summer and then take it all apart the following winter to build it into a stroker
and i dont mind spending money if the endresult will be big power ;)
just 24 years old and realy try to build this already powerfull smallblock into something that makes enoug power to push the car far into the 10second zone without nitrous and as a real streetcar without sacrificing my interior or enlarging my rear wheelwells so it has to be done on big power i gues ...
realy apreciate your help
 
duster340,
They do have a stock pattern on the exhaust but they also have the pattern for the race hedders. The original W-2 heads had a stock pattern and later they went to a spread pattern, the exhaust is double drilled, so either will work. The stock pattern is very close to the ports. Send me your e-mail and I'll send you some pics.
 
BJR Racing thanks! i truly apreciate your knowledge will PM my emailadress!
do you think the largeport comando heads are overkill even on this application now that you have some more facts that i forgot to mention from the start?

and are my goals possible to reach?

now i have e TTI headers and would like to keep them for some more time but if they end up restricting to much power when this is all done i will build my self a new set of bigger headers with W2 flanges on them

thanks agian
 
BJR Racing said:
Duster340,
The shafts are different and the rockers are offset .485 on the intake side only, you'll need .180 offset shafts for the spacer blocks.
Click to expand...
BJR, What are different about the shafts? And what are spacer blocks. Are they the "Stands" like the W-2 heads to adjust the shaft height and such?
 
Rumble,
The shafts are offset drilled .180 so the bolt hole will be off center .180, this is for rocker arm clearence and spring clearence. As for the spacer blocks they are just like the W-2 but aluminum and they are driectonal.
 
Will W-2 rocker stands interchange? Or any gear?

I still want a set of these to kill some people in the street. Come on lotto. LOL
 
The race W-2 rocker gear will interchange as will the W-5 stuff, infact the W-5 spacer blocks are used, and the W-5 offset shafts. The spacer blocks for the W-2 are steel or cast iron and don't mix aluminum with steel as you know which material will win the wear test. Not to say that they will be moving back and forth but the electrolsis of 2 different materials composites. It may work for a while but just beware that the aluminum will be wearing, or deteriating first.
 
you sure know these heads!

but will they realy be that much too big on a 340 with about 12.5:1 compression and a solidrollercam with .650 lift and 268/272 degrees of duration at .050 with a holley strip dominator intake manifold and of course a bottomend that is as bulletprof as a stockblock and crank can bee?
will these heads suport enough power to go some mid 10seconds at the track on a stroker engine? i gues a stockstroke 340 is to small for that
yes its a streetcar but its a very very agresiv engine already i know that and i am used to driving around with a rough idling smallblock with poor low rpm power but i know i forget all about that poor low rpm as soon as the engines screaming..
BTW streetcars over here in sweden are known to push the limmits alitle to the extremes for some reason ;)

thanks alot in advance
 
duster340,
These heads will work great on a stroker engine and they will be high RPM's on a shorter stroke engine like the 340, I would say 7500-8000 on the 340 and 6000-6500 on the stroker with the parts listed, (cam and intake) I'm sure that the stock bottom end parts won't hold up to this, not without a 4340 crank and 4340 rods.
We had a W-5 engine that was a 365 and with the W-5 heads it turned 6500 through the 1/8 real easily with a solid cam that had 255 @ .050 and .540 lift. It ran 10.90's @ 3190 lbs. @ 4400 ft of elevation so the 10 sec. range isn't a problem N/A, we loaned the engine to a guy with a Daytona to try and he ran 10.63 thru the 1/4 at 3000 lbs. so it isn't hard to do.
 
BJR Racing
the block is stock but has fourbolt billet maincaps and have a half fill of blockfiller crank is a forged stock 340 crank and some I beam rods that i cant remember who made hope those rods and the block prepp should be good enough for the stroker iam planing i hope i can get away with putting a revlimmiter in the msdbox for next season then to keep the revs low enough to alove the bottom end to survive one season before i build a better bottom end
looks like i have planed an engine powerfull enouh and with some good machine work and quality parts and lots of patience with asembling it it may last for a while too
i gues a rollercamed stroker with these heads could bee a handfull on the street but i will get used to that:)
 
Sounds like your going to have alot of fun! The block should be sturdy enough as long as the rpm's are kept down, I guess it really depends on how much harmonics the engine is really seeing. The better the blueprinting and balanceing the longer it will last.
 
well this botttom end is very wellballanced for now but i will keep the revs down for sure to make it live safe until i have enough money to build a stroker that wont need any real high rpm 340 blocks are stupidly hard to find over here last one i found whas over 1200$ with one mounting ear cracked and poorly welded and alreedy bored out.040 and with big wearsigns in the bores:( so i realy try to make this block survive!

thanks alot!
 
You must log in or register to reply here.
-

Back
Top