440 upgrade advice

[aatkinson]

Hi everyone. Wonder if someone can give me some advice.
I have a stock 440 in my Jensen and am looking to improve the performance. nothing too wild just decent off the mark acceleration
The engine was a recon unit from a place called motorworks in Spokane and I'm assuming it has stock compression (8.2 to 1). I have fitted eddy performer plus inlet manifold and have performer plus cam and a pair of eddy performer rpm ally heads (84cc) sitting boxed and ready to fit. I'm keen to keep my stock rockers. Question is will this give me a marked performance improvement? I figured the stock compression may be a limiting factor? I dont really want to fit new pistons. Assumng i have smogged stock heads will the eddy heads improve compression? Also does anyone know if I can run the rpm heads with stock rockers?? The eddy head instructions mention the need for adjustable rockers if fitting aggressive cams. I'm assuming that as the performer plus is a relatively mild cam I'll get away with stock rockers.
Thanks
Alex

[440roadrunner]

Personally for a "mild upgrade" it's my opinion that spending money on expensive aftermarket heads is a waste. The only way to know for sure what you have for compression ratio is to actually measure it, but even with low compression, it would probably benefit from a mild cam and possibly improving your exhaust. I realize that "over there" you are at a huge disadvantage for parts, and I'd guess headers are non-existent for a Jensen, but maybe some of the performance manifolds off the RR/GTX/ etc might fit. Changing the cam timing and optimizing ignition timing could make a huge difference.

Do you know, for example, what you have for a distributor advance curve? What do you have for a carb?

If you decide to raise compression, new pistons would be a heck of a lot cheaper than aftermarket heads

How on EARTH did you end up with an engine clear over here from Spokane?

[340_GTS]

I's a 99% probability that you'll need adjustable rockers, and new pushrods with that combination. With the cam, lifters, and heads changes, there is a 99% chance the stock non-adjustable rockers won't be putting the correct preload on the lifters.

[John Kunkel]

Welcome to the board aatkinson.

You failed to mention the year of your 440, if it's '72 or later and was rebuilt with stock pistons the actual compression ratio will be around 7.8-1. The factory open chamber heads have a volume of around 88-90 cc's so the 84 cc heads will boost the compression but the aluminum heads will nullify that because they absorb more heat.

[DartGT66]

Change the pistons to higher CR, use flat tops at zero deck. The performer cam is really gutless, I would use for example http://www.summitracing.com/parts/CCA-21-227-4/ instead to take advantage of the heads you have.

[cudabob496]

power equals airflow, so from the air filter to the exhaust, it all has to be able to pass the air and exhaust. For your setup, a cold air intake would be very helpful (as the engine compartment is tight and runs hot). ramairbox.com. Also, right now, your exhaust system may be a major power inhibitor. K&N filters help, and synthetic oils free up horsepower too (and make your engine run cooler). Also, make sure to match the cam to the compression ratio, or your cam may bleed more cylinder pressure than you want! For that car, an aluminum radiator helps with the cooling as well.

[440_8bbl]

hello here is my 02 and its just 02,
Jensen nice car btw, ok your 440 it sounds like you would like to get some more go and not get into a total rebuild of the motor.
So go a head bolt the stuff on and you will be fine use the stock rockers adjustable rockers are a total waist of money on a motor that will only see the street and yes take care of the exhaust, clean up the flow if you can.
if you would like to dig a little deeper look up "Old Reliable 440"
yes i have one and yes it kicks ass even with my ported "smog heads"
on my 73 440
you can spend a lot of coin and not go any faster so the stuff that you have got will help.
just make sure the cam will work with the heads in terms of flow, its all about the total package working together.
you do not need a big cam for that motor,
look up 4 seconds flat they use Racer Brown cams if you have any questions.
good luck

[aatkinson]

Guys thanks for the great replies, this 440 amateur really appreciates the advice. When I get back from my vacation I'm going to measure the compression as I'm 99% sure the block is later than '72 (it's not the original block). If it is really low then I might consider new pistons. In terms of exhaust I have a pair of custom 4 branch headers waiting to be fitted (bought and shipped here to england with the heads and cam) and have also gone 2 inch all the way through to the back. I'm also considering a cross over pipe? Im still unsure whether I need adjustable rockers, the cam instructions say use stock but the heads say if using cam with greater than stock lift use adjustable. I'll spk to edelbrock and see what they recommend. Cold air sounds like a good idea. Lastly anyone have any tips or links to sites that explain how to measure compression on a 440 and how to choose pistons if the compression is really low (based on what I've read I'd like to aim for low 9's ratio but have no idea how to work out how to choose the pistons) thanks again. Alex

[440_8bbl]

dude why do you what to do a compression check?
so you do one and you find one or two cylinders are not the same and you will, now what to you do. sit and fret, tell your bud's.
pull the motor apart, or drive the ****'en thing!
you need to make a plan and the way i see it you have 2 choices.
bolt your new shiny parts on and drive it like you stole it!
or pull the motor out and rebuild the thing.
take it from me i am a fng too and a few old timers told me not to take all the fun out of it.
440 are tough sob's and make wayyyyyy more power that you will ever need in that car. and they make it basically really really close to STOCK.
if you are looking for really good advice go to the local drag strip when it warms up and talk to the guys and really hear to what they have to say.
don't believe the parts hype let the chevy guys spend all the money on the fancy stuff it was made for them anyway.

if you really what to dig into your motor contact Don at 4 seconds flat
or 440 source or google 440 old reliable.

remember have fun, make a plan stick to it and drive the ****'en thing!

[aatkinson]

Sorry pal, I meant work out what my compression ratio is. Agree though, as I've bought all the parts probably better to bolt on a see how she goes.

[buckneccid]

You didn't mention what tranny and rear combo you have, and that's pretty important if you want to have a good leave. The stuff you're gonna bolt on is gonna move your HP up in the power curve, so you need something to take advantage of that. I'm pretty sure your Jenson is an automatic, and gonna assume you have something like a 3.08 or 3.23 in it (If I remember right, Jensons got a Chevy 12 bolt). My suggestions? After you bolt that on, get you something like a 2800 stall convertor. You will suffer a little in gas mileage, but when you nail the throttle, it'll be a little like dumping the clutch at about 2400 rpm. The convertor is only gonna stall to where the torque overwhelms the resistance.

And while it's not totally accurate, you can use a rule of thumb trick to get an idea of what your compression ratio is by doing a compression check on one cylinder. You said it's a rebuilt unit, so your compression should be pretty good. Ambient air pressure @ sea level is approximately 15psi. If you assume 100% efficiency, then 10-1 compression @ sea level would be 150 psi. 8.5-1 would be 127.5 psi. If you look up your altitude and see what the ambient air pressure is where you are, you can adjust from there. In reality, you're only gonna have about a 90% efficiency from a fresh engine, so 8.5-1 would be 114.75 and 10-1 would be about 135. This is just rough, it's not totally accurate, but it would give you something better to go by than "I think it's just...."

Using a 10-1, .030, 440 source heads, and old weiand single plane, headers, MSD box, 750 Holley and a Lunati Voodoo cam with the .530 range lift (split) along with a 2800 stall and 3.55 gears, I was getting an adjusted 1/4 mile time of 13 flat (13.08) in a 71 GTX, thru the mufflers, on street tires. I liked it

[bulldog426]

even the smog heads were good especially the 452 casting heads they were alot similar to the older 906s as far as chamber ccs and porting, i'd go with a set of high compression pistons to start with keith black, speed pro, etc but don't do like i did and get the step head dome pistons because i got those and am now really limited on what kind of heads i can run because i can only run open chamber heads with thos pistons and i've already spent alot of money on those pistons far as geting my rotating assembly balanced and everything else and at the time i was planning on using some cast iron ported heads but now i'm wanting better heads

[cudabob496]

A nice MSD ignition setup, with the 6AL box, distributor, and wires, helps a lot too! The distributor comes with several ingnition curves that are easy to install.

[fat 360]

Um...Imma just gonna add my two lil bits...god I hope you have the original engine for that Jensen Interceptor....Those engines in them WERE NOT STOCK!!! I was lucky to see an engine from one disassembled in the mid '90's.When's the last time you saw shiny combustion chambers out of factory cast???Jensen tidied up the motors before they went in kids...

[Moparmatt72]

I just want to add you said you were gonna run 2" pipe out the back???? If you want it to breath go 2.5-3inch on the exhaust. 2" is restrictive. Cross over pipe is a must with mopars, either a X-pipe or H-pipe. Its up to you on this I personally like the H over the X.

[cudabob496]

Originally Posted by Moparmatt72

I just want to add you said you were gonna run 2" pipe out the back???? If you want it to breath go 2.5-3inch on the exhaust. 2" is restrictive. Cross over pipe is a must with mopars, either a X-pipe or H-pipe. Its up to you on this I personally like the H over the X.

I just put on a 3 inch X. Had a 3 inch H. Seem to have more power now!
I'm guessing 15 to 20 hp.

[mhenesian]

Hi attkinson,

If you want to stick with Mopar stuff, I'd swap that very mild Edelbrock performer cam for a the old 383/440 magnum cam, 268/284 degrees with 0.458" lift. I've run this cam many times with stock parts and 3.23 gears. I think Mopar performance still sells then, including lifters (DCC-4452783 $177 Summit Racing online). It will work great with the Perfomer 440 manifold and the new heads. Or for more power, since you have the new heads with the 1.55" diameter "Hemi" springs (good for 0.550" lift), you might try the Lunati 268/276 voodoo cam plus lifters LUN-60303LK with 0.494/0.513" lift (here again Summit Racing online $209). These will work with the stock pushrods and rockers arms, no trouble, and the low compression is actually an advantage since you will not have any piston to valve clearance issues. Just make sure to "recurve" the distibutor to allow around 16 degrees initial advance, and no more than 38 degrees total advance (with the vacuum disconnected). The Mopar cam uses the single bolt timimg gear (like the Edelbrock cam), while the Lunati requires a swap over to the three bolt timing gear,

Mark

[Moparmatt72]

Originally Posted by cudabob496

I just put on a 3 inch X. Had a 3 inch H. Seem to have more power now!
I'm guessing 15 to 20 hp.

The X does make a little more power over the H, I just like the sound of H over X.