Got my heads off (pics). Shave heads before reinstall? Anything else?

[Wakko]

We got the heads off my 440 and were pleasantly surprised to find out that the previous owner was truthful when he said that the motor was rebuilt recently.  Unfortunately they used low compression pistons ( L2388) which would explain why the car ran on 87 octane without dieseling or pinging.  Car was obviously WAY out of tune (I already knew that though) with the amount of carbon on the pistons.  Cross hatch is good, .030 overbore with a purple shaft, .484. 

Here's my question.  I have to get the heads worked on due to two header bolts being stripped out.  We're also going to clean up the castings a bit and maybe open up the ports a tad, nothing wild.  Should I shave the heads while they're out to pick up some more compression?  We estimated the CR to be at around 8.5:1 right now.   I don't plan on racing the car (maybe once for grins, but that's it) and don't usually drive it crazy.  When I DO get on it, it's from about 30-60 and once in a blue mood past that.  If shaving the heads would give me significant gains, I'm for it...but if it's only 10-20 HP than I doubt it's worth it.   One of my local buddies is trying to convince me to slap a 150 shot on it since the CR is so low, but I'm not seriously considering it at this point.  If I DID do that, it'd mainly be for effect.

Anything else I should do to this engine while it's apart?  We're resealing it, cleaning/repainting it and that's it.  Oil pan is stock and needs the holes undimpled.  Casting plugs are steel, not brass, but they're not leaking...don't want to create a problem.

Engine is at TDC in these pics, BTW.

[firefighter3931]

Looks pretty nice in there Ian !  At this point you might want to check the valve seals while the heads are off and replace if needed. A quick mill to true them up should be fine. Use the steel shim head gaskets and spray them with copper coat before reinstallation.

Honestly, the best thing you could do for performance is to swap out the cam. The 284 at 238*@.050 is way to big for an 8:1 compression engine. A cam with 220*@.050 (or less) would be much better matched.  

If you're dead set on keeping the 284 at least degree it in and advance the cam timing to help with cylinder pressure.


Ron

[Wakko]

Would that explain why the car always stumbled when you hit the gas?  Seemed like no matter what we did, the motor wouldn't tune.  I'd really like to keep the bumpity bump idle it has, how lumpy is a 220 cam?  Would shaving my heads bring the CR up enough to warrant the original (and still new condition) cam?

[firefighter3931]

The reason it sounds lumpy is because of the long duration, tight lsa and low static compression. What sounds good and what performs well are often 2 different things. 

You could machine the heads to increase the static compression but that can lead to other issues such as rocker arm geometry, pushrod length and intake port alignment. You other option is to obtain some closed chamber heads with smaller chambers to increase the static compression. The proper way to do it is to swap out the pistons but that's not practical in this situation because the engine is so fresh.

That leads us back to the camshaft which is the key. You ideally need to spec the grind around a pre-existing build which unfortunately wasn't your making. This is the easiest way to achieve your end goal, inmo without tearing down the shortblock or getting into major head modifications. You can spec a custom cam with a tighter lobe seperation angle to give you that lope but the duration should be shortened for better performance and tunability.

The mistake made with your engine is probably the number one issue with street engines that perform poorly....the wrong cam for the combo.

Ron

[Wakko]

So that could by whe the engine never really ran right?  You can see it was super rich, always stumbled off the line.   Good call on the valvetrain clearances, I didn't think of that...guess I won't be shaving the heads. 

If I put the smaller cam in there it'll just idle normally, correct? 

[firefighter3931]

So that could by whe the engine never really ran right?  You can see it was super rich, always stumbled off the line.   Good call on the valvetrain clearances, I didn't think of that...guess I won't be shaving the heads. 

If I put the smaller cam in there it'll just idle normally, correct? 

Ian, for sure this type of motor is very difficult to tune. Idle vaccum is so low that the carb has to be set up rich in order to get it to idle at all. Low vaccum creates a weak signal at the venturi booster and not enough fuel is pulled down to idle the engine properly. In an attempt to establish some semblance of an idle, the idle speed screw gets cranked down and the transfer slots are completely exposed. At this point the idle mixture adjustment is no longer functional because the engine is now idleing on the main circuit and not the idle circuit. This could very well account for the carbon buildup on the pistons.

A smaller cam will make it easier to tune and a whole lot funner to drive. Your plugs will stay cleaner, longer and the torque/power will come in much sooner. The Engle K54 is ideal for what you're looking for and will make power well into the 5000+ rpm range. With stock heads that haven't been ported, that is where you want to be in terms of the powerband, inmo. 440's are torque monsters so take advantage of that stroke and burn some rubber. This isn't a BB chebby that you have to spin to the moon to get anything out of ! 

If you want it loud, just throw on some chambered mufflers (not my preference) for the desired effect. 


Ron

[Just 6T9 CHGR]

I used the K56 Engle cam (224º @ .050) in my 9.3:1 440 and had them grind it @ 108 for a bit of lumpiness......

PS----if you have 906 (88cc) heads the CR with those pistons would be 7.83:1

[Wakko]

I do have 906 heads, unfortunately.  I emailed the previous owner to find out who made the engine parameter selections and haven't heard back.  I don't know whether to find smaller chamber heads (415 is it?), put new pistons in there or just bolt it back up and deal with it. 

This may seem like an idiotic question, but bear with me.  Considering how fresh the motor is, if I WERE to buy new pistons, what would I need to do to the motor?  Do I need to rehash the bore to use new rings, or can I reuse the rings that are on there?  Bearings?

This motor is just BEGGING for an iron lung or spray with this CR. 

[firefighter3931]

The 2355 six pack slugs will give you approx 9.3:1 compression with the current setup (open chamber 906's). If everything is good (rings/bearings) then they could probably be reused.....but i allways use fresh rings with new pistons.

The 516/915 castings are closed chamber, but most of those are small valve and what you gain in compression, you lose with flow so it's often a tradeoff in terms of power. If the closed chamber heads have the big valve upgrade/bowl porting then you will increase compression while maintaining flow....then you're ahead of the game.

All of those options seem rather complicated & expensive compared to doing a simple cam swap. Any reason you're married to the 284 cam ? There are much better grinds out there. I guess i have a hard time understanding the reluctance to swapping out the cam when it would achieve just about everything  you want with the least amount of hassle and expense.  The reality is that on a combo that is this mild...the 284 might make a few more hp at redline but will give up a lot of torque and bottom end power down low. As you've seen ; it's a bear to tune with the low compression combo. I'm not a fan of the MP purpleshaft hydraulics. The 284 needs at least 9.5:1 compression and 3.91 gears along with a 3000 stall to perform well. It is more suited to a higher powerband from my experience....and yes i have run that cam in the past.

Ron

[Wakko]

No, not married to the cam at all.  Just trying to correct the possible 7.8 : 1 compression ratio.   

[firefighter3931]

Ian, can you get ahold of a dial indicator and magnetic base ? The purpose wuld be to measure the piston to deck clearance and then calculate your compression ratio with all the measurements in hand. Those pistons look like the speedpro 2266's which normally sit .080 below deck and will yield in the mid 8's for compression. The later (74-78) cast pistons sit .140 below deck and typically yield lower static compression results similar to the 7.8:1 you think you have.

It's hard to tell from the pic, but your pistons don't look that far in the hole. A measurement would go a long way to figuring out what you'v got....and the right course of action to get it sorted out.   


Ron

[Wakko]

The pistons say L2388 030 on them, and I'm pretty sure that's a Sealed Power number.  I wonder if he went to Autozone and got them.     I'll ask my LCB if he has those items, if not I'll try to track them down or bring the motor somewhere to check it. 

[greenpigs]

Wakko

I am in the same boat with a low cr 440, mine has a slightly smaller cam 272\280 though.

  My plan WAS to get some close chamber heads and do the larger valves and new bronze guides and some port work. But I can get some edelbrock heads for a few hundred more than what all that work would cost. Now I am trying to figure out if I should bolt on the e heads and go with it or yank the motor and put some higher cr pistons in. If I pull the motor its going to run close to 1500 at least for new pistons and machine work along with the new studs and cam. I think my summit brand cam chewed up a lobe slightly as when I dropped the oil pan a few years ago it had a pile of metal. I want to go with a solid cam but am intimidated by the valve lash settings and possiblly screwing it up.

The idea of a 400+hp 440 is VERY tempting and should be easy to do with firefighter and pyscho here. Oh yeah pleanty of others to help with the combo also. My plan spec wise is something like this as I am just giving general specs.

10.5 actual cr..a ross or diamond piston
.030 overbore - yes with tourqe plates-I have a virgin block
Eldebrock 84 cc heads
Re-use stock steel crank and connecting rods
Solid cam with unknown specs I gotta ask around I guess.
I have a weind action plus but I think a performer rpm intake might be better.
Then some kind of adjustable rockers

After that I will need to get a higher stall convertor, which is more money & I have a 4.10 gear with sure-grip.

Sorry for the high-jack

[Just 6T9 CHGR]

The pistons say L2388 030 on them, and I'm pretty sure that's a Sealed Power number. I wonder if he went to Autozone and got them. I'll ask my LCB if he has those items, if not I'll try to track them down or bring the motor somewhere to check it.

That is the Sealed Power part #

I have the L2266 .030 pistons in mine.  With my 915 closed chambered heads they yeild approx 9.3:1 compression.

When I got my motor, believe it or not, on a fresh rebuild it had the 2388's in there as well!

I went from getting the engine (rebuilt with approx 100 miles on it), pulling the heads to do a "check" to swapping pistons, clean up honing the engine, bearings, rings, seals , cam etc......

[firefighter3931]

The 2388 must be a cast piston ? If it is a sealed power number, i would assume that is the case. 

Ian, if these are cast slugs in your motor i wouldn't advice that you spray it. The cast pistons are brittle and don't tolerate shock loads like a forged piston would. See if you can get some measurements :

(1) piston to deck
(2) Chamber cc"s on your 906's

Chris, any idea how far in the hole the 2388's are ? Compression height ?


Ron

[Just 6T9 CHGR]

Ron, IIRC they were over .120 down.....
Scroll down on this link to see specs......they are forged

http://www.campbellenterprises.com/mopar_speed_pro_trw_forged_pistons.htm


Heres a pic of them in the engine before I yanked them

[firefighter3931]

Ron, IIRC they were over .120 down.....
Scroll down on this link to see specs......they are forged

http://www.campbellenterprises.com/mopar_speed_pro_trw_forged_pistons.htm


Heres a pic of them in the engine before I yanked them

Thanks Chris....that is enlightening. I looked at the specs on the Campbell website to see exactly what those were. The 2288's are even lower (shorter) than the 2266's which is surprising. Using the supplied compression height specs those pistons will yield right at 8:1 with an 88cc chamber and a .020 (compressed) steel shim head gasket. 

Ian, if you decide to keep this engine intact, the cam timing must be kept short to build cylinder pressure and torque ! 


Ron

[is_it_EVER_done?]

As long as you have the heads off, and are going to do work on them anyway, I would get them cut .080 which will help out the compression. You will need to shim the rocker arms the same amount as you cut off the heads, but shim kits are readily available from Mancini, Jegs, and others for dirt cheap. --- You will also need to have the intake surfaces of the heads milled the proper amount, depending on how much the surface is milled. -- I am going to let someone else tell you how much, as I'm not sure/can't remember (getting old SUCKS!), -- but I believe it's .0123 off the intake surface for every .010 off the deck surface --- Can someone provide the correct ratio for certain?

You should measure the deck height of your pistons at TDC. Even a reading from a machists rule would be of help in figuring your compression ratio, but I'm guessing from the pics, that you are at about 8:1. An .080 cut should put you in the high mid 8's, to near 9:1, depending on your head chamber cc's (Stock, they fall in the near 90cc range from my experience).

As others have said, your cam is way wrong for your combo. My suggestion is to contact Scott Brown at Straightline Performance. Give him all your specs, car use, driving style, car weight, gears, etc., and he can come up with a cam that (I personally) would put against anyone else in the industry! The man truly has a gift for calculating specs for a given combo and environment. -- link --> http://www.straightline-perf.com/. If you do decide to go this way, tell him how much the heads were cut so that you don't run into valve to piston clearance problems.

[firefighter3931]

You will also need to have the intake surfaces of the heads milled the proper amount, depending on how much the surface is milled. -- I am going to let someone else tell you how much, as I'm not sure/can't remember (getting old SUCKS!), -- but I believe it's .0123 off the intake surface for every .010 off the deck surface --- Can someone provide the correct ratio for certain?

Yep, that is the correct formula. So, if you took .080 off the deck surface you would need to take .096 off the intake side which would leave them dangerously thin and difficult for sealing up the valvecovers. Shimming up the rocker arm shafts .080 wouldn't be my preference, either.

Basicly it boils down to living with the current shortblock and speccing a cam to make it work....or swapping out the pistons to increase the static compression. The 2355 six-pack replacement slugs would give you ~ 9.3-9.5:1 and allow you to keep the 284 cam...

Straitline could spec ot a cam but i think you'd find that his recommendation would be similar to the Engle k54....something in the mid teens @.050 with a wide 112* lsa. It might be worth a call for a second opinion...


Ron

[Wakko]

You guys have brought up alot of good points, thanks for the all the input.  The engine will definitely not be going back together the way it is.  I'd REALLY like to bring the compression up to mid 9s for performance but I have to see what I can afford.  If I can swap out the slugs inexpensively without getting bit by the "While I'm here..." bug, I'll do it.  For my application, standard rings and cast pistons would be ok I would imagine.  My question is still though, what can I reuse?

FF, who sells Engle cams besides Engle?  I see they're big in the VW world but didnt' see them on Summit's site.

[Just 6T9 CHGR]

I bought mine along with matching springs direct from www.englecams.com

[firefighter3931]

You guys have brought up alot of good points, thanks for the all the input.  The engine will definitely not be going back together the way it is.  I'd REALLY like to bring the compression up to mid 9s for performance but I have to see what I can afford.  If I can swap out the slugs inexpensively without getting bit by the "While I'm here..." bug, I'll do it.  For my application, standard rings and cast pistons would be ok I would imagine.  My question is still though, what can I reuse?

FF, who sells Engle cams besides Engle?  I see they're big in the VW world but didnt' see them on Summit's site.

A forged piston would be preferable....if you ever decide to spray it you won't shatter a slug. The 2355's would fit your combo perfectly and give you enough compression to make the 284 cam work. I would install a new set of "moly" rings and reuse the bearings if they look good.

Like Chris said, Engle cams are sold through the manufacturer direct. I'm not aware of any venders that sell them other than Engle, themselves.


Ron

[Steve P.]

8:1 .........    Put a blower on it......       JK..

Wakko, even if it takes some time to put the bucks together, figure out exactly what you want and do it ONE TIME. It is more costly to do things over and over and not be happy with the way things are at the moment.  BEEN THERE!!!!!  Try not to hurt your build just because you wanted to save a hundred bucks. You are truly better off knowing exactly what you want and building EXACTLY THAT..

[mikepmcs]

 

[Wakko]

You're right Steve, that's for sure.  Unfortunately alot of my total car renovation (not restoration) is going to put me in the red for a while so while I don't want to be a cheapskate that's taking compromises where I shouldn't, I don't want to leave any stone unturned if I can save some cash.  I will NOT be putting this engine together half ass and have to redo it later.  If I can only afford a cam swap and end up with a 300 horsepower motor, that's ok...I'll still have fun with it.  Just would be nice to have a 400 horsepower rumbler.    I tell people constantly that I enjoy my 15 second Charger more than my 12 second GN!  And it's soooo much sexier.      Minus, ahem, a/c...seatbelts..radio..locking doors...