ZZ4 upgrades

ZZ71s said:
http://forum.grumpysperformance.com/viewtopic.php?f=50&t=2883&start=0&st=0&sk=t&sd=a&view=viewpoll
I am going to replace the number 7 piston.
So,do I need to also replace the rings and bearing and is there any other thing I should think about when replacing just one piston ?
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any time you have the engine down like that its a good idea to replace ALL the rod and main bearings, but, if its low mileage you could get by with just replacing the defective piston & bearing, and re-using the rings if a close inspection shows they are ok,
its always a very good idea to check bearing clearances, make sure the new piston weights and measures just like it the one its replacing and yes replacing the all the rings is usually at least an option, and while the rods out have a shop verify the rods in good condition, and does not need to be replaced or rebuilt, and when you replace the rod/piston assembly take the time to re-torque all the rods and main caps.
keep in mind the rings should be fine and they should already have lapped into that bore so they should not require you to change rings or re-hone the cylinder, but the rod and bearing have impacted a solid object and tried to compress it, adding a good deal of repeated stress to the rod and bearing, that will require very close inspection and swapping to a new rod bearing is a total no-brainer here in my opinion,due to the repeated impact abuse

deglazing the cylinders probably only a good idea if all the rings get replaced, as you don,t want hone grit in the cylinders, but yes ITs been done thousands of times and careful cleaning with rags and some diesel fuel will remove most of the crud, magnets and your oil filter should get most of the little you miss.
personally Id carefully inspect the rings and re-use them if they looked good, if not then replace as required
 
Grumpy
I just got off the phone with GM pp looking for torque spects for rod bolts they said 20 foot pounds and 55 degrees have you heard of a spect like this?
 
ZZ71s said:
Grumpy
I just got off the phone with GM pp looking for torque spects for rod bolts they said 20 foot pounds and 55 degrees have you heard of a spect like this?
Click to expand...


yes, I have,its a torque/angle spec and without the correct tool, to measure it its useless
BUT ID suggest you use 45 lbs on a torque wrench
after snugging the rod bolts up in there stages (20lbs
35 lbs -45 lbs), and loosening them ,1/2 turn, and re-tightening the 45 lb three times, the cycling seats and equalizes the final reading

viewtopic.php?f=50&t=1222
 
Grumpy
I have a quench question for you.
The stock zz4 pistons are down in the block about .025 and the zz4 stock head gasket is .0501 compressed with a 58 cc chamber dosent this give the zz4 .075ish quench,but the engine has a 10 to 1 compression ratio with this combo.
I have read that a good quench is more close to .045ish so how inportant is the quench in building a good engine?
Heres my combo ZZ4 short block with pistons down in the block .025 and AFR 180 eliminators with 62 cc chambers with a .039 compressed head gasket or should I use http://www.summitracing.com/parts/NAL-10105117
.025 down in the block and .028 give a quench of .053ish or will my compression ratio be to high
feel free to straighten me out on this quench stuff.
 
your finding the pistons .025 below the block deck height is almost routine on an un-milled block.
most factory produced and assembled engines tend to almost ignore effective quench as a factor during their assembly simply because the tolerances need to be tighter, to achieve effective quench, than its cost effective to build, under mass production conditions.
or put a different way, if the tolerances required are kept tight enough to build that true effective quench the production engine cost would be significantly higher.
so production engines basically ignore the potential gains because its simpler to just reduce the effective compression, and loose some of the potential power , with slightly lower effective compression.
you gain about 3% in torque for every point in compression, or put a different way a 400hp engine at 10:1 cpr can reasonably expect to gain 1.5% in torque at 10.5:1 cpr if nothing else changes.
so the more efficient engine with the better quench should produce about 7 ft lbs more or 407-425 hp in that particular case,depending on the torque peak rpms resulting from the 1.5% increase in torque over most of its rpm band.
horse power is the measure of the rate at which torque can be supplied, the formula is torque x rpm/(divided by) 5252=horsepower


swapping from a .039 thick head gasket that gives you a 10:1 static compression and a .065 quench to a .018 head gasket that gives you a much more effective .043 quench would boost your static cpr to about 10.56 , that at least in theory would boost your torque about 1.5%

heres a compression ratio calculator

http://www.kb-silvolite.com/calc.php?action=comp








you might want to read thru these, keep in mind its the small changes that COMBINED make the difference between an average and an EXCEPTIONAL ENGINE COMBO....change the rocker ratio, the cams LSA, the header primary length, the collector design, get the ring gaps correct, the quench right, the ports smother, the valves back cut., the valves un-shrouded,the combustion chambers pollished, the bearing clearances correct, the windage tray, design, and oil pan installed correctly,the cam degreed in vs just dot-to-dot, the valve train geometry right,etc..etc, it all adds up, the small changes can easily stack to give your an extra 30-80-100 hp PLUS OR MORE, more than a similar engine without the tweaks required for it to excel


viewtopic.php?f=52&t=727&p=7096&hilit=quench#p7096

viewtopic.php?f=53&t=726&p=5640&hilit=+quench#p5640

viewtopic.php?f=52&t=1070&p=4829&hilit=+volumetric#p4829

viewtopic.php?f=52&t=322

viewtopic.php?f=56&t=1166
 
So using a thinner head gasket may improve the quench and compression what are the drawbacks of using a thinner head gasket?
 
ZZ71s said:
So using a thinner head gasket may improve the quench and compression what are the drawbacks of using a thinner head gasket?
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the ONLY one IM aware of is that thinner gaskets MIGHT NOT seal as well, and that some aluminum heads tend to brinell, or dent slightly with some gasket designs,making the thicker gaskets almost mandatory, now obviously that assumes the clearances are correct and both the heads and block are correctly machined and have decks that are square to the crank center-line, not warped.
both the block and heads must be dry, grease free and the gasket makers instructions followed, Ive usually torqued the heads down in three or for stages and used the correct outward spiral pattern.
OBVIOUSLY , if your at all in doubt, making a call to the cylinder head manufacturer and head gasket manufacturer is not a bad idea before the install


viewtopic.php?f=50&t=1222
sbchvy_head_seq.gif
 
Grumpy
I think this weekend is going to be engine re assembly.
So i have a few questions on the piston rings the top one 180 to the second one what about the third set?
The torque spect from GM for the rod bolts is 25 lbs and 55 degrees but you and the tect at GM said 45 lbs in three stages should I release the pressure on the bolt and re torque in stages three or four times and then check the plasta gauge.
What kind of sealent do you use on head bolts?
When I check the clearences with the clay in the cylinder will torqueing the new head gasket mess it up?
 
Grumpy
I think this week end is going to be engine re assembly.
So I have a few questions
1. What kind of sealent do you use on head bolts
2. Piston ring gaps the top one 180 degrees from the second one what about the third set?
3. Will torqueing the new head gaskets when I check the clearences with the clay mess them up?
4. The torque spect from GM is 25 lbs and 55 degrees but you and the tect at GM said 45 lbs in three stages but should I release the pressure on the rod bolts 3 or 4 times and re torque before checking the plasta gauge?
 
ZZ71s said:
Grumpy
I think this week end is going to be engine re assembly.
So I have a few questions
1. What kind of sealent do you use on head bolts
hightack.jpg

viewtopic.php?f=44&t=700&p=973&hilit=+sealant+threads#p973

2. Piston ring gaps the top one 180 degrees from the second one what about the third set?

viewtopic.php?f=53&t=2837&p=7342&hilit=ring+gaps#p7342

ringindex.gif


3. Will torqueing the new head gaskets when I check the clearences with the clay mess them up?

you don,t torque the bolts while checking clearances you simply snug them lightly, into place, maybe at 15 ft lbs, and you generally use only 4-6 head bolts

4. The torque spect from GM is 25 lbs and 55 degrees but you and the tect at GM said 45 lbs in three stages but should I release the pressure on the rod bolts 3 or 4 times and re torque before checking the plasta gauge?
Click to expand...

yes, you need the bolts torqued to spec. but be careful to lube the threads, and personally I don,t torque them during clearance checks to the full 45 lbs, 42 lbs will do until final assembly, and if youve got one a rod bolts stretch gauge is always a great cross checker
 
Grumpy
I installed the new rods and pistons today I got some assembly lube on the rod bolt threads do you think this might be a problem
 
ZZ71s said:
Grumpy
I installed the new rods and pistons today I got some assembly lube on the rod bolt threads do you think this might be a problem
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Id doubt its going to be a huge issue simply because you generally use oil on the rod bolt threads before torquing them to specs anyway, but youll want to read thru this ARP POSTED INFO BELOW carefully, being consistant is more important than having the rod bolts torqued to 2-5 percent out of the torque specs in most cases on a street motor

FROM ARP
If the stretch method cannot be used in a particular installation, and the fasteners must be installed by torque alone, there are certain factors that should be taken into account. ARP research has verified the following “rules” pertaining to use of a torque wrench:

1. The friction factor changes from one application to the next. That is, the friction is at its highest value when the fastener is first tightened. Each additional time the fastener is torqued and loosened, this value gets smaller. Eventually the friction levels out and becomes constant for all following repetitions. Therefore, new fasteners should be tightened and loosened through several cycles before applying final torque. The number of times depends on the lubricant. For all situations where ARP lubricants are used, five cycles are required before final torquing.

2. The lubricant used is the main factor in determining friction, and therefore, the torque for a particular installation. Motor oil is a commonly used lubricant because of it’s ready availability. If less friction is desired in order to install the fasteners with less torque, special low friction lubricants are available. With special lubes, the required torque can be reduced as much as 20 to 30 percent. It is important to keep in mind that the reverse is also true. If the torque value has been specified for a particular fastener on the basis of low friction lube, installing the fastener with motor oil will result in insufficient preload; the torque has to be increased to compensate for the extra friction caused by the motor oil.

3. Surface finish is also important. For example, black oxide behaves differently than a polished fastener. It is therefore important to observe the torque recommendations supplied with each fastener.

NOTE: It is possible for even the most expensive of torque wrenches to lose accuracy. We have seen fluctuations of as much as ten (10) foot pounds of torque from wrench to wrench. Please have your torque wrench checked periodically for accuracy.


viewtopic.php?f=53&t=247&p=7191&hilit=torque+wrench#p7191


viewtopic.php?f=50&t=989&p=1744&hilit=+stretch+gauge#p1744

this
is the reason the stretch gauge is superior, and use of ARP ROD BOLTS it much more consistantly measures the tension or clamp force the rod bolt is under
arp-100-9942_w.jpg

We highly recommend using a stretch gauge when installing rod bolts and other fasteners where it is possible to measure the length of the fastener. It is the most accurate way to determine the correct pre-load in the rod bolt.

Simply follow manufacturer’s instructions, or use the chart on page 25 of the ARP catalog for ARP fasteners.

Measure the fastener prior to starting, and monitor overall length during installation. When the bolt has stretched the specified amount, the correct preload, or clamping load, has been applied.

We recommend you maintain a chart of all rod bolts, and copy down the length of the fastener prior to and after installation. If there is a permanent increase of .001˝ in length, or if there is deformation, the bolt should be replaced.
 
don,t worry your taking far more effort than most guys do and theres thousands of engines out there running fine that were assembled with less thought, going in to their assembly, you should be fine!
 
IBob said:
It would appear, or at least the claim is that this (below) ARP lube will eliminate the multi-torquing requirements.


http://www.summitracing.com/parts/ARP-100-9910/
Click to expand...


from long experience , over 35-40 plus years and cross checking the torque wrench readings against the bolt stretch suggested by ARP., I can tell you that even with the correct lubes you need to cycle the bolts thru at least three tighten and relax cycles to get consistency results,, the thread surfaces need to to wear in. , yes I tried that lube, and while its good its not a cure for the need to cycle bolts or use a stretch gauge or a torque wrench

BTW don,t get crazy and think you absolutely can,t build engines without a rod bolt stretch gauge, that's simply not true!, while its a great tool, its use is not mandatory, but use of a good torque wrench and consistently cycling the bolts per the ARP instructions , results in very consistent results

arp-100-9910_w.jpg


heres the stretch chart


http://www.arp-bolts.com/Tech/TechTorque.html
 
I think I might have a lifter problem I got a push rod stuck behind one of my GM stock zz4 roller lifters I think it might have tweeked the lifter when I lashed that valve it was alot harder to turn that poly lock than all the others.
Do you think I should replace that lifter?
 
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