Worth the trouble?

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THE STEVE

THE STEVE

"part-time wheelman"
Joined
Nov 23, 2009
Messages
322
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15
Location
springville, indiana
hey gang, i got a 77 van 360 engine in my 72 duster. stock bottom end, stock pistons (dished). heads have been ported quite a bit with stock valves.

cam is an erson 4.88lift 292duration i think (been a few years since i built it)

intake is a victor single plane with a holley 650dp. and a proform HEI dist. 2400 stall, 8.25 rear with 3.55s

flowtech headers.


my question is: would it be worth it to tear the engine down (has less than 10k miles since built) and install flat top pistons? also maybe install larger intake and exhaust valves? i know both of these thing will help performance, but will it be worth the trouble? or should i just keep what i got and save for the 440. i got a 440 but that would require a whole drivetrain swap again, and i dont plan on having the money for that in a few years. i work at a machine shop and i can do the labor for free. my boss (cale kern speed shop) has given me his 2 cents i was just wanting a second opinion. id like to also swap 4.10s in soon.
 
this car isnt a cruiser. just on weekends i drive around town but it wont see the hwy much and i plan to race it at the local 1/8th mile track
 
I like those cams.

IMO, yes, install new pistons. The ones mentioned or KB-107's and have the block milled if need be for a zero deck height on the pistons. Use the mentioned cam(s) above to suite the driving needs. (Smaller one is a great choice.)

Keep everything else. The intake is large enuff. A swap would only make me install a RPm for better drivabilty and torque. Everything else stays the same.

I think the 440 swap a cool idea, but a expensive one. And for a street cruiser...honestly, I really do not see the point have having both like set ups.
 
What is it you are trying to do "for now"? Is there a lack of power you're trying to overcome?
 
its simply just not fast enough for me. its probably a mid 14 sec car in the 1/4. im not looking for streetability. im looking for the most power possible with what i have.
 
Might try an Air gsp manifold,bump the mid range very well.
 
the manifold is a lil out of app.imo
the carb is a lil small as well for top end power on a 360 with anything over 274* adv duration.

What do the heads flow now?
bigger valves will only help flow, thats a given....but only if the bowl is blended properly to the larger seat cut.

id have the heads flowed and see where you stand, then either work them more or not, but either way...cam for them...and then carb it for the intended rpm power range etc..

as for pistons...depends where u are now compression wise and how much higher u raise it. it could be worth 8hp or almost 20hp+ if ur at 7.8 and go to 9.5 or more.
mainly, a bigger cam along with more compression and a bigger carb that sits on a dual plane intake which pulls harder on that carb which will in turn mix better...will make a lot more power than what u have now.

could be 35-40 hp more or so...

pick and choose.
the intake swap to dual plane especially if ur under the 7500 rpm range will make more torque up higher too, through out the range, the bigger carb '750' will raise the peak torque and broaden it as well....and thats just bolt on's.
add a good timing curve/tune and who knows....might find that 30hp right there.

if only we could all take it for a spin and check/play with the tune...all depends on where ur starting from i guess.
 
the heads are the stock van heads. not sure on the casting number. but they have been ported and had some bowl work done. i gasket matched them to the intake and exhaust and smoothed them pretty good. not sure what they flow.

the compression ratio is whatever a van motor was stock. probably 7.5 or something close.

the intake i used because i got it brand new at a swap meet for $40. the carb i got for free and rebuilt it.

i was thinking maybe bump the comp up to around 9.5 to 10. and possibly change stall converters. as well as 4.11 gears. it drives fine and has a good launch for what it is. but i know there is alot more there. the timing has been tuned to 36 degrees full advance i think.

the engine i built in highschool when i was flat broke. now im bored of it and want MORE! lol.

my boss told menot to mess with it unless i wat to go throught the whole thing again. its never been bored, the engine had 50k miles on it when i tore it apart. there was still factory cross hatchings on the cylinders so i honed it and left that alone due to money.
my boss told me to leave it alone and just save for aluminum performer heads, as well as carb+intake upgrade and then ill notice a gain.

i just dont know where to start. i hate the thought of buying $1500 set of heads if i can work with what i got.

also i shift it at about 6300rpm. by then its pretty much out of steam.

thanks for all the info guys.
 
3 years ago, before the intake, carb, and stall swap and before setting the timing. it made 205hp at 238 ft torque on the dyno. kinda sad isnt it?

but after what few parts i changed made a day and night difference. the hp and tq is still probably low.
 
You have a heck of a bunch of mismatched stuff there. No compression with big cam and massive intake = real dog.With stock compression on the 360 and stock heads you should be using a little smaller cam and a dual plane intake.The Victor is a 3500 to 8000 rpm design. The carb is probably more than enough but not too large.As a starting point I would just switch to a performer RPM manifold and that should help a lot.If that dont get you where your going I would go with a slightly smaller cam with a little less duration. Duration equals rumpity rump but overlap also bleeds off cylinder pressure which is already low because of your pistons.I would say something in the 270 duration range.. That erson is a 2000 to 4000 rpm cam.If you do decide to take it apart use the KB 107 or a forged equivilant so you can 0 deck it and then you can get by with the erson cam and a performer rpm.
 
Dont put the edelbrock heads on this shortblock or you will have a super dog. Even if you got the small chamber heads the aluminum would still have negative effect on compression ratio. Perhaps pick up another 360 shortblock(usually cheap or free) put in some KB 107's(around $250) and then swap it in with your other stuff but still ditch the Victor because its way out of wack with what your trying to gain.
 
Boost. Add boost.

You have low compression pistons. Add cylinder pressure the old fashioned way.

.
 
yeah, i realized along time ago that everything i had wasnt lining up. but, its what i had. i have a buddy that might sell me his offy dual plane intake cheap. would that fit the bill?

i once thought about a cheap turbo kit. but i dont really want to do that anymore.

ido have a 5.9 magnum block from a 99 truck that has a slight rod knock. i thought about building it since its already a roller motor.but im not sure if the crank is bad. and i dont really have the $$ to build an entire new engine.
 
yeah the A #1 thing you should do is get a good set of pistons that gives you a good compression ratio and good quench.... whichever ones you get read their specs (the KB site has info for their pistons) about what your deck height should be etc. depending on the piston set it would be zero deck or a little below or a little above. choose your pistons before you get the block done so it's matched correctly and you get proper quench

also make sure they are the ones that work for your heads (open chamber / closed chamber / etc. the piston choice depends on the heads and chamber size you are using)
 
if i get new pistons and raise the comp up to lets say 10.5, what intake/ stall / carb should i use then? would what i have be good? or should i still change intakes?

remember, im looking for as much balls out performance i can get. i realize that without spending a ton of money and building some crazy stroked engine that i wont be the fastest ship in the galaxy. but i am looking to squeeze 100% performance out of that 360.

or would it be better to just tear the entire thing apart and change rods, pistons, heads etc etc. and not even dick around with the stock stuff i have now. i know all in all stock stuff wont be lightning fast or reliable but will it be at least respectable?
 
it's all about how far you want to tear down the engine.

the heads in stock form are actually good for 400 hp before porting, that is if you had the rest of the ingredients.

can you do a cranking compression test and report back ?
 
If he goes with kb107s he would get more compression, but they weigh alot less than the factory pistons. The h116cp will get him into the 9 to 1 range but the pistons weigh the same as stock dished pistons (according to my scale). This way being on a budget he doesnt have to have it ballanced, it would be a good idea, but i would think he could get away without it. He is running open chamber heads, 0 decking isnt super important, he could always mill the heads to up the compression or run thin head gaskets.
 
Stick the dual plane manifold on and take it for a drive then get back to us. Boost will cure some of them problems but if you cant afford a short block you surely cant afford a turbo kit.
 
I think you're looking to get cool sounding stuff, but overlooking the problems you've created by doing that with what you have now. Spend the cash you were going to spend on pistons, rings, and gaskets on a used dual plane Performer or Performer RPM, and a used 750 carb. SPend a little on a performance ignition or to curve the distributor you have. You can get much faster without adding more mismatch.
 
thanks. im not looking for "things that sound cool" im looking for all options.

i asked before but what about an offenhauser dual plane intake? its not an airgap but will that work?

i also thought about milling the head as well. itll be a week or two til i get home next. between school and work i dont have a single day off. ive worked a constant 16 days now. but hopefully i can get home to the 72 duster. and as suggested ill get a compression test to report back with. i was thinking about giving sam jones a call. he owns a shop in the washington area and does performance engine work as well as head work for alot of the nextel cup cars.
hes pretty well known around here. maybe he can add more light to what i should/shouldnt do to my heads or block.
 
I think by simply changing the cam, intake, and carb, plus simple tuning you can get huge improvements. I wouldnt touch the lower end at this point. What valve springs were installed with that cam? Can you determine what the ignition curve is?
 
The cheapest way I can see to band-aid the miss matched parts would be to get an Air-gap intake, and a Proform main body for you carb (to make it a 750dp). I think that is less than 400$ for the 2 parts, unless you can find good used stuff.

Beyond that a cam swap would probably help (not knowing the exact cam specs).
 
..call Fank Lupo,give him all your info.
have him build you a 9.5" converter and add a dual plane manifold
..i think you'll be surprised with the change in street performance.
 
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