360 build questions.

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On the balance question: For 2 grams, I would either not worry about it, or drill a little metal out of the piston pin area and make it the same as the originals. I have raced 6-7-8k RPM 4 bangers, NA and turbo, with simple piston changes with no issues or worries. BUT (and this note is for Bad Sport) make sure you also compare the pin weights if you have not done so already; they can change by many 10's of grams from stock Mopar to aftermarket. It is the total piston+pin+ring+ lock weight you are after for this case.

My point was that when you change piston type, like a big change in CR, or different piston style with the same process and material (forged, cast, etc.) OR change in material like from cast/forged (heavy) to hyper's (lighter), then the balance needs to be revisited 100%.

When you do your home balance for a V8, read up on how to weigh the rod's big end and small end weights. Balance the rod big end+bearing wieghts to each other, and then balance the rod small ends + pistons/rings/pins/locks to each other. The 2 rod end weights are handled differently in the balance process of the crankshaft. It is not that haed at all; it is a 'recipe' process.

A $100 eBay accurate gram scale+calibration weight set is OK to use for this for most engines that will not spend 500 laps at 7-9k RPM, IMO. It would not be adequate for NASCAR or Indy or F1.
 
As far as taper goes - I don't measure for it. I test the lifters for rotation in the block using WD40 for lubricant and rotating the crank by hand (usually before the pistons and rods are mocked up). That way the inconsistencies in the lifter bore angles and lifter bore wear are also "considered" by the process. You could measure the cam and think you're good, but the actual installation and true interaction between the lifter face and lobe face don't instill a rotation because of the block machining that nobody ever checks. It's kind of caveman-ish, but at some point measuring takes moretime than mockup does...lol
They either all turn, or they don't. If they don't, move some around until they all do...
 
The way they were slapped together back in the day it's amazing they ran .
 
nm9stheham said:
When you do your home balance for a V8, read up on how to weigh the rod's big end and small end weights. Balance the rod big end+bearing weights to each other, and then balance the rod small ends + pistons/rings/pins/locks to each other. The 2 rod end weights are handled differently in the balance process of the crankshaft. It is not that hard at all; it is a 'recipe' process.
Click to expand...

Yup, already have the gram scale and weight. I just have to make a jig to do the rods, then I will go through all of the pistons, pins and rings, find the lightest set and make the others match.
 
moper said:
As far as taper goes - I don't measure for it. I test the lifters for rotation in the block using WD40 for lubricant and rotating the crank by hand (usually before the pistons and rods are mocked up). That way the inconsistencies in the lifter bore angles and lifter bore wear are also "considered" by the process. You could measure the cam and think you're good, but the actual installation and true interaction between the lifter face and lobe face don't instill a rotation because of the block machining that nobody ever checks. It's kind of caveman-ish, but at some point measuring takes moretime than mockup does...lol
They either all turn, or they don't. If they don't, move some around until they all do...
Click to expand...


When I spoke with Richard at Bullet he suggested I check the lobe taper on the cam. I did so, and every lobe does have taper so I'm good there. If nothing else, I learned something, lmao.

I will check the bores as you suggest. And I am measuring everything, as I want to learn as much about the intricacies as possible.
 
You can measure the bores, but you cannot measure how far off the bore is in terms of it's relationship to the cam lobe. That is dependant on the acuracy of the cam bore, and each lifter bore. Just like the deck or anything else - the bores can be raised, lowered, or angled in relation to the cam lobe. That's what Hughes ran into when they pushed the fast lift rate to the mathematical limit, and that was why they said some blocks may need the lifter bores addressed after cams were getting eaten.
 
Anything wrong with using a single valve spring as long as it meets seat pressure and open pressure?
 
Also, the heads I have, have been milled.

I understand it might be better to mill the intake side of the head instead of the intake?

I have an LD340 intake, and I don't really want to mill it.

Thoughts?
 
Bad Sport said:
Anything wrong with using a single valve spring as long as it meets seat pressure and open pressure?
Click to expand...
I always understood that the 2nd spring can eliminate some physical resonance issues in the valvetrain related to having just one spring rate. The 2 spring rates can 'fight' each other if the parts are moving/flexing at a rate to try to resonate with the single spring. The closed and open spring pressures are static measurements. Some valve train issues are dynamic problems; i.e, those have to do with the mass and speed associated with the rapid motion of the parts, and flexing in the parts.
 
Bad Sport said:
Also, the heads I have, have been milled.

I understand it might be better to mill the intake side of the head instead of the intake?

I have an LD340 intake, and I don't really want to mill it.

Thoughts?
Click to expand...
Mill the part you value the least, IMO. We decided to mill the Performer intake because that is a lot less valuable than the new Performer heads.
 
Bad Sport said:
I have always understood balancing the rods, balancing the pistons to be equal weight etc. Where I got messed up was balancing the whole rotating assembly.

It sounds as though IT needs balance and one still needs to balance externally.

I do not wish to balance internally where it would require Mallory metal added to the crank. Trying to keep costs down.
Click to expand...

Lets rewind to 'nickel content' of the block...

--- Rock solid Main saddle bores could give a farg less about internal or external
balance ---

Just by way of info Bad Sport,
'Tinfish' developed a low order harmonic knock (3rd short fuse 273/318/340 composite build)
I sent oil & metal samples to the TRW TECH TEAM... remember Thos Guiz?
Got a call back--- wanting a sample from the block..." to properly diag failure".

:D
 
Each spring used has a certain point at which it can no longer control the valve. This has less to do with pressure, and more to do with harmonics and the material, diameter, and number of coils per spring. A single spring will succeptible to anything outside of it's "comfort level". Add a second spring with a different material, number of windings, or wire type and diameter, and they will cancel out parts of the total harmonic, raising the rpm range the "spring team" can reach before the loss of valve control limits it. That's one of the reasons the dampener is in performance single springs. It's very economical, fits with stock seals and retainers, and has a drastically different frequency where it would no longer work. Used in tandem with the single round wire spring the "team" are extrememly effective. So my advice would be use what the cam maker wants you to use. If there is a choice single or double as in some Comp designs, the reason not to use the double is purely financial - singles with dampeners go right in, duals need head work to fit. But the trade off is the single w/dampener designs are maxed out, and in some cases they maynot work as well as duals, and definately will not have the life expectancy of the duals in the same application.

Milling - I cut the intake flange on the heads first. It makes changes later easier and at least at my shop it's cheaper than setting up an intake if the head's already in the fixture.
 
moper said:
Each spring used has a certain point at which it can no longer control the valve. This has less to do with pressure, and more to do with harmonics and the material, diameter, and number of coils per spring. A single spring will succeptible to anything outside of it's "comfort level". Add a second spring with a different material, number of windings, or wire type and diameter, and they will cancel out parts of the total harmonic, raising the rpm range the "spring team" can reach before the loss of valve control limits it. That's one of the reasons the dampener is in performance single springs. It's very economical, fits with stock seals and retainers, and has a drastically different frequency where it would no longer work. Used in tandem with the single round wire spring the "team" are extrememly effective. So my advice would be use what the cam maker wants you to use. If there is a choice single or double as in some Comp designs, the reason not to use the double is purely financial - singles with dampeners go right in, duals need head work to fit. But the trade off is the single w/dampener designs are maxed out, and in some cases they maynot work as well as duals, and definately will not have the life expectancy of the duals in the same application.

Milling - I cut the intake flange on the heads first. It makes changes later easier and at least at my shop it's cheaper than setting up an intake if the head's already in the fixture.
Click to expand...

Thanks, I'll stick with at least a spring with damper.

I haven't mocked up the heads/intake yet, but, I would rather mill the intake flange on the head than to commit an LD340 to those heads.

I do have a Weiand though that i may consider milling.
 
Does anyone know what the crush thickness is on these: Victor Reinz/Clevite #695-3536SG

Thanks
 
We run a single spring (350 open/135 closed) on a dirt mod running 7200 rpm's with a 525 lift cam with 243 duration without issues
 
Who said head porting was easy??

Grrrr..................... what a slow process.
 
Yep.. that is part of why my son and I are bypassing that step in the current build. But it hopefully will give you a real sense of satisfaction when done.
 
nm9stheham said:
Yep.. that is part of why my son and I are bypassing that step in the current build. But it hopefully will give you a real sense of satisfaction when done.
Click to expand...

Well, this whole build is a larnin' experience, lol. I'm not really porting per say, just blending and cleaning the intake side, and cleaning and polishing the exhaust side.

I hope, at the very least, it does make some difference.
 
Bad Sport said:
Well, this whole build is a larnin' experience, lol. I'm not really porting per say, just blending and cleaning the intake side, and cleaning and polishing the exhaust side.

I hope, at the very least, it does make some difference.
Click to expand...

Done halfway right,you're gonna notice it Bruce..
 
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