big block cyl head question.

1967coronet · Apr 1, 2018

I just picked up a low compression 1976 motor home 440 with low miles, its the 440 -2
engine with the car style heads and water pump.
the heads are 452s.
My question to you guys that know tons more than me on these heads is.
Will the better flow of the 452 heads in stock condition preform better that a stock set of 516s with the small exhaust valve with the 516s slight bump up in compression.

Im working with what I have on hand and just wonder if the bump in compression of the 516s is worth the loss of the better flow 452s or is it a wash ?
I know new pistons and a port job on the heads is the best for this deal but I am going to leave the bottom end as is for now.
going with a dual plane intake , 750 eddy, RV style Hyd cam and headers, electronic ignition , pan & pickup swap, ethire set of heads will just get a standard trip through the local machine shop, crack check, check guides, grind the valves and new seals
Thanks.

cryplydog · Apr 1, 2018

I would stay with the 452s tested-resurfaced-and a performance valve job and the dual plane. you can call comp cams and get a mild grind with valve timing that will bring up cylinder pressure/compression for the style of driving that you intend to do. For a street car I wouldn't look for a power band any over 5300/5500. Solid lifters and factory style adjustable rocker arms would be the ticket for me. you need a good distributor etc. and a reasonable stall converter about 2500/2800 would help. good luck 67, I like these projects, reminds me of when I was a younger feller. Hang on.

BeepBeepRR · Apr 1, 2018

452 heads have hardened seats and will tolerate todays shitty gasoline. 915 heads are closed chamber heads 452's are not. However all of the research I have done tells me there isn't a huge difference in all cast iron BB heads. You can check through my RV 75 440 build.. https://www.forbbodiesonly.com/moparforum/threads/picked-up-a-low-mile-440-today.143842/

Mine was sitting for years in a field. It needed to be bored but the crank was in great shape. The pistons were bad from sitting for a long time. I bought an 800 dollar summit Speed pro piston kit and had the block square decked bored and honed. My pistons are at .005 in the hole. My heads were rebuilt and larger springs were installed. Went with a K6401 cam Should be pushing 10.3:1 compression ratio with .039 head gaskets and 88 cc chambers in the 452 heads.
Engine guy told me 500hp with 650 tq

BSB67 · Apr 1, 2018

BeepBeepRR said:
...My heads were rebuilt and larger springs were installed. Went with a K6401 cam Should be pushing 10.3:1 compression ratio with .039 head gaskets and 88 cc chambers in the 452 heads.
Engine guy told me 500hp with 650 tq

That's a little optimistic.

1967coronet · Apr 1, 2018

Thanks for the replies guys, I read your thread beepbeep, good info and sounds like a nice combo.
I most years put 2 to 3 thousand miles on my old 67, my 65 383 has a rattle down low so its coming out this summer before something lets loose and kills it.
I snagged this 440 worth the $ and just want to put it in so I have my car for summer.
I just want to get it up to 300 hp and build some torque up.
My old 383 has been getting tired and I may redo it next winter. Just need to get this 440 up and going for summer.
Thought about just dropping it in and see what happens, but I figure better at least pull the heads and look things over. Then I start over thinking stuff ,like sticking the 516s off the 383 on it LOL. Bench racing with myself in the shop. If the cyls look good I will just freshen up the 452s and small cam it , put my tri y headers on and get it out for summer.

BeepBeepRR · Apr 1, 2018

BSB67 said:
That's a little optimistic.

Lol thats what he told me. However.. I have no idea hes the engine guy not me. But those are the numbers he gave me. I didnt want to go that big anyhow. So if its not, then I'm ok with that.

I was just hoping for a hone job but it ended up costing me a ton more. Sadly the 350.00 440 ended needing a lot more than I had planned.

mopar 3 B · Apr 2, 2018

A 440-2 thats unusual.

1967coronet · Apr 2, 2018

mopar 3 B said:
A 440-2 thats unusual.

I never new about it myself, From what I can tell its a truck/motor home post 1972 deal.
Just another cast number added. from what I can find the {3} was the truck 440 that had the extra water jackets and different coolant pump.
Keep in mind this is what I am reading on the google ect. So it could be all bs.
When I get to work I will hunt through the Chiltons.

BeepBeepRR · Apr 2, 2018

mine is 440-2 as well here is the block. Late model 440 block info here. Note the cooling holes at the lower side of the cylinder 2 holes per cylinder. And the wider cooling between cylinders up top. 1,7,2 and 8 appear to have 3 cooling holes.

Here is a 70 440 block.

IQ52 · Apr 2, 2018

1967coronet said:
Thanks for the replies guys, I read your thread beepbeep, good info and sounds like a nice combo.
I most years put 2 to 3 thousand miles on my old 67, my 65 383 has a rattle down low so its coming out this summer before something lets loose and kills it.
I snagged this 440 worth the $ and just want to put it in so I have my car for summer.
I just want to get it up to 300 hp and build some torque up.
My old 383 has been getting tired and I may redo it next winter. Just need to get this 440 up and going for summer.
Thought about just dropping it in and see what happens, but I figure better at least pull the heads and look things over. Then I start over thinking stuff ,like sticking the 516s off the 383 on it LOL. Bench racing with myself in the shop. If the cyls look good I will just freshen up the 452s and small cam it , put my tri y headers on and get it out for summer.

Start at the beginning and stop when you are at the horsepower you want.

https://www.forabodiesonly.com/mopar/threads/dyno-testing-a-stock-1972-440.249866/

wyrmrider · Apr 2, 2018

Those extra coolant holes were not unusual in late engines- they match the late heads that also have holes- to cool the sparkplugs
so use the matching heads
BTW you cannot easily drill non late heads for the holes as the castings have some bumps in them
even so the early small combustion chamber, different port heads will have a little more low end and a little less top end
but with some basic porting/ clean up and late larger ex valves it can all even out
however the late heads had induction hardened exhaust seats that's had if they have had a couple of valve jobs
what pistons do you have in that block and what is your deck clearance- looks good

1967coronet · Apr 2, 2018

Thanks again guys for the ideas and replies. I looked over IQ52s link and the results he got with a low comp 440 and bolt on parts is just what I am after.
I pulled the top of 440 apart this eve plugs looked dry but to rich, bores look great , no ring grove or scoring , pistons are the non cut flat tops so far down off the deck I didn't even bother to get the dial gauge out.
Heck you could put corn flakes and milk in them at top dead center and have breakfast. LOL
This project of mine is on the cheap. I will pull a couple rod and main caps and look things over if good they will go right back on.
Im in it for $600 at this point.
I will rob what I can use off my 383. Ive got a rb distributor and 750 edelbrock, I have the headers but will have to get a cam kit chain & gears , aluminum intake and gasket set.
I have a convertor off a 76 400 that should work ok to keep from shaking this apart.
The valves look good in the 452s didn't see any cracks off the seats rocker sets looked nice and clean no sign of heat or non oiling problems , I may just stick a new set of seals on them and go if the quides do not feel to loose and swap in the cam kit springs at that time, this 440 has under 40,000 on it so we may be good.
I should be in this for around $1,500 and be a little north of 300hp and around 400lbs TQ If I get lucky and have the same results IQ52 did.

wyrmrider · Apr 2, 2018

good thoughts
do 400 converters have balance weights?
does your Motor home motor have heavy "6 pack rods" (is there any balance weight on the balancer?)
now those motor home valves are super premium Inconel exhausts and SIL XB intakes (check the prices for new ones-They are hard chromed- not just "flash" chromed- flash chrome is actually just to keep them from rusting
Hard chrome takes a copper primer coat, then nickel, then grind to just a fur 10ths under size, the chrome and finish grind- that's one reason they are pricey
Cam selection is critical- intake close point- for a low compression BBM
do check the deck clearance and CC the heads before cam shopping
wrong cam might have a little more top end HP above 4000 rpm but cost many ft lbs of torque below 3500 especially at converter stall speed
cheers
the bigger dog bone holes up top are to get the sand out easier- they work the same
some truck heads had hard insert seats- see if you do but I doubt it

rumblefish360 · Apr 2, 2018

Flow over squeeze every time!

BeepBeepRR · Apr 3, 2018

wyrmrider said:
good thoughts
do 400 converters have balance weights?
does your Motor home motor have heavy "6 pack rods" (is there any balance weight on the balancer?)
now those motor home valves are super premium Inconel exhausts and SIL XB intakes (check the prices for new ones-They are hard chromed- not just "flash" chromed- flash chrome is actually just to keep them from rusting
Hard chrome takes a copper primer coat, then nickel, then grind to just a fur 10ths under size, the chrome and finish grind- that's one reason they are pricey
Cam selection is critical- intake close point- for a low compression BBM
do check the deck clearance and CC the heads before cam shopping
wrong cam might have a little more top end HP above 4000 rpm but cost many ft lbs of torque below 3500 especially at converter stall speed
cheers
the bigger dog bone holes up top are to get the sand out easier- they work the same
some truck heads had hard insert seats- see if you do but I doubt it

My engine guy said my valves cleaned up real easy.. and said they were something I cant remember but I think what you said above is what he was saying. Also My heads had hardened seats. Also this is the cam I have in the 440 SUM-K6401.

dvw · Apr 3, 2018

Just me but bargin basement build. Use the 452's. Clean the valves. A little lapping compound and spin the valve against the seat . ( I use a Makita. Move the valve on/off the seat a few times whole spinning slowly). Does it seal all the way around? Good to go. Check bearings, add a chain cam, lifters, springs, intake and go. Mild cam so you can use existing rockers and pushrods w/o maching the guides for clearance. Or get carried away
Doug

wyrmrider · Apr 3, 2018

agree with rumblefish- go with the flow did you bowl blend/ that's well worth while DIY project
you already own the cam? put it in 4-6 degrees advanced and give it a whirl, report your cranking compression and how it drives
you have to know that the advertised duration is SAE- .006 at the valve or .004 at the cam (same as Crane) so it looks longer than when compared with Comp who use .006 at the cam or way different than Engle or Isky who use .008 +
let's see how it drives b 4 thinking of a cam change
The one I'd use is about - well a lot shorter with about the same lift please post back as you go along

1967coronet · Apr 3, 2018

wyrmrider said:
agree with rumblefish- go with the flow did you bowl blend/ that's well worth while DIY project
you already own the cam? put it in 4-6 degrees advanced and give it a whirl, report your cranking compression and how it drives
you have to know that the advertised duration is SAE- .006 at the valve or .004 at the cam (same as Crane) so it looks longer than when compared with Comp who use .006 at the cam or way different than Engle or Isky who use .008 +
let's see how it drives b 4 thinking of a cam change
The one I'd use is about - well a lot shorter with about the same lift please post back as you go along

I have not yet bought the cam kit. It just has the stock 440 motor home stick in it right now.
Once I get this up and going I will let you guys know how it is.
I will be using the heads as they are, I will do the valve lap and add springs that come with the cam kit and new seals.
It will prob be mid may before the switch out happens with the engines.
Thanks for the advice.

wyrmrider · Apr 4, 2018

I read IQ's links
never ran a Hughes Whiplash but I think I see the design idea
use a Max .904 lobe to keep the seat duration down while still giving lots of area above .200
then use a tight lobe center to get the intake closed early
usually this gives you too much overlap but in this case with the short duration it's not too bad
but that's looking at it backward
start with where you need the intake to close and work out all 4 of the timing events
the lca is a byproduct not an input
BTW- just about the opposite of the Summit cam- no way with low compression IMHO you are giving up maybe 40-50 ft lbs at 2500

wyrmrider · Apr 4, 2018

couple of examples
lift 1.6 1.5 lobe adv .050 .200 lsa IC
.528/536 .495/503 .330/335 NA 216/220 NA 112LSA 0-36/46 -6 -6 overlap 3.0-3.55gear HUG SEH1620BL-12
.552 .518 .345 NA 229/242 NA 107LSA 13-36/54-8 +5 overlap Hughes Whiplash SMC2942BL
While we still can't tell where the intakes actually close these are not lazy cams and both go past 36 degrees ABDC at 36 degrees
overlap changes a some but that's not too much overlap- headers would be nice
but you are getting 229 @.050 instead of 216
466/488 298/304# 224/324 114lca 3 41 56 2 54 overlap Summit 6401 #adv at .004

the summit would have a really late (compared to either of the above with the wide 114 lca and much longer seat duration and not much lift gain over magnum
510 480 .320 268@ 224/230 110lca .842lifter XE268H
comp chevy cam looks better than the Summit chevy cam but look how a MOPAR 216 @50 cam blows it away (other choices for MOPAR cams also but you have to dig)

big block cyl head question.

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