first hotrod build

I'm glad you got it from the manufacturer. I wonder how they measure that 20 lbs? Did you find
out about the oil ring expander and how it's supposed to work/adjusted?
 
I have found nothing on adjusting oil ring expanders. It seams they are set at factory, the wavy expander can compress at set rate with top and bottom oil scraper rings in place.
 
I would like to know how well desktop dyno 2000 represents a build and cam interaction, not so much exact numbers but the representative curves on the graph. Within my 6000 rpm redline I am not seeing a lot of difference between two different cams 278/278 howards and recommended crower 286/292. the howards has a bit higher and flatter torque curve but looses about 10 hp at 6000 where I will see but I don't see me using often but I could be wrong. The crower has lots more hp topping at 7000 that I wont use with a large overlap that will sound really great and not so great gas mileage and the howards will have a nice idle and better mpg with a 58 degree overlap. If dd2000 gives a good representation of these two cams and the build its self I am inclined to go with the howards or a comparable duration cam - not set on any particular brand but unsure of comp cams.
 
on the street youll almost always find that the lower duration cam in the choice between two similar cams will in the long term be a slightly more useful choice.
(the simple reason why is that most street cars spend the vast majority of the time operating well below 4500-5000 rpm, and lower and mid rpm torque not peak hp is used far more often) it hardly makes sense to build any engine to produce its peak power in the rpm range you,ll rarely use. and the extra duration will generally reduce the low and mid rpm torque you use the vast majority of the time, in exchange for a bit more peak power you'll rarely access.
 
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Have you tried Rick's DCR program yet?
Play with it, you will see how the IVC point affects (or is it effects) your DCR.
 
I have worked with Wallace calculators and 64 degrees abdc gives me 8-1 dcr I think this should be about ideal for street and pump gas.
 
ok I think my short block is done finally. a clearance question, when looking down the cam bore the rods peek up into the bottom of the bore when sighting along the bottom of the bearings, is this normal or not. Getting ready to buy the cam so I have not checked clearance there, rod to block has plenty as the scat rods say they are clearance for 3.75 stroke and block was machined for stroker clearance.
 
look through these threads

http://garage.grumpysperformance.co...earances-and-journal-surface.9955/#post-38385

http://garage.grumpysperformance.com/index.php?threads/clearance-issues.12072/#post-57822

http://garage.grumpysperformance.co...g-and-installing-connecting-rods-pistons.247/

notice how the rod bolts come close to the cam bearings and cam lobes,as the pistons reach top dead canter in the bores, this clearance must be individually checked and should be no less than about .060 (generally you cam use a LARGE plastic tie-wrap, you must install the timing set and index the cam correctly to get a valid clearance , as the cam lobes rotate and at some point they can be incorrectly indexed too hit the rods, while they would not if correctly timed.
https://www.amazon.com/BuyCableTies...D=41U9CtmwOuL&preST=_SY300_QL70_&dpSrc=detail
12cal.jpg

41owudXrErL.jpg


placed between the cam lobe and connecting rod bolts or connecting rod shoulder areas to check clearances as the soft tie-wrap will not damage the cam lobe while you verify clearances)

block-clearance.jpg

clearancedrod.jpg


rodcaptocamclearance.JPG

rodcaptoblockclearance.JPG




BaseCircleDiacv.jpg


why you need to verify the cam to rod bolt clearance

rod-grinding.jpe

on some stroker applications SOME rods need to have the bolts ground for cam lobe clearance
 
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my rods are scat 3/8 cap bolt and I will probably use a howards 272/278 112 lsa cam with .350 lobe lift with a 2 degree advance. I was hoping to find a way to see if there is a clearance problem before I buy. appreciate the tip with tie wraps to check for clearance. verifying has saved me more than once so yes I am checking everything.
 
I don't think anyone is going to be able to predict the clearances. Maybe Howard's would have some
experience, but that's the only one that might have an opinion. It's also going to depend on which rods
you have and their shape.

I found that solid copper wire that you would use to wire a house with in 12 or 14 gauge works well. You can
bend it and it will retain the shape you want so you can snake your way into the pinch area.

CamToRodClearance1649.jpg

CamToRodClearance1650.JPG
 
ok starting to get it together. Talked to scat and 3/8 cap bolt 6"rods are not stroker clearance so they may or may not clear and will probably need to be clearance ground. Warned not to touch the ARP bolts or they are ruined. Disassemble once more, I have a belt sander to use, any useful links for how to do the rod grinding for clearance.
 
Maybe you could return the rods you have and purchase ones that would clear or at least be closer to clearing. I know it's more money, but it's an option. With rods like the ones below you would not be grinding on the ARP bolt, they don't extend thru the top side of the rod.

DSC00348.jpg

DSC00342.jpg
 
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DEAL IN PROVEN FACTS NEVER GUESS , NEVER ASSUME
first step.

before you start panicking and potentially wasting money and time.
would be to assemble a single piston and rod assembly without rings,
but ideally with some old bearings on the crank and connecting rod and install the cam, in the block
( indexed with a simple,dot to dot timing on the timing gear sets should be ok at this point)
move that connecting rod and piston to all 8 locations and very carefully verify clearances (remember the rod clearance bevel faces the crank counter weight and the piston valve clearances face the outer block)through the full 720 degree rotational cycle, remember the cam spins at 1/2 the crank speed so the cam lobe comes close to the rod every other rotation,
and actually verify you DO, have or DON,T have a potential clearance problem
theres zero sense in runninbg around pulling your hair out and screaming until,
theres actually a PROVEN ISSUE too SOLVE (THERE MAY NOT BE!)
now if you find theres an issue to be solved you proceed using facts
and while your checking the cam lobe to connecting rod clearance check the connecting rod to block clearance ....yes the same minimum .060-.080 clearance is suggested
lobeclear.jpg

http://garage.grumpysperformance.co...earances-and-journal-surface.9955/#post-38385

generally its a minor easily done clearance job
camlcc1.jpg

camlcc3.jpg

camlcc4.jpg

camlcc5.jpg

camlcc6.jpg

camlcc7.jpg

http://www.scatcrankshafts.com/index.htm
don,t forget to verify the cam to connecting rod clearances
a cams VALVE LIFT is determined by the DISTANCE the lifter moves as the cam rotates under the lifter base as it moves from the cam lobe base circle
(the closest the lifter comes to the cams center line)
up to the cam lobes ramp to the lobes peak,
(the furthest the lifter up off or from the cams center line)
don,t forget to carefully check the piston skirt to crank counter weight clearance, it should be a MINIMUM of .080 thousands
heres some pictures taken of an engine assembly that use a crank designed for a MINIMUM of a 6.25" connecting rod that was used with a 6.135" connecting rod


p140811.jpg

piston1.jpg

you can clearly see where the piston pin boss was being hit bye the counter weights, even though the builder checked one piston and found it had .025 clearance during assembly
pistontocrankclearance.jpg


the result was a trashed engine with lots of damage

piston2.jpg


 
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ok I can handle this with the links. I will check and get the right clearances, just another disassembly to do it right. The rods do have more clearance than stock rods so I shall see. Already talked to scat about rod replacement and they would be happy to sell a set of clearanced 7/16 rods to me but I get to keep the rods I have. I would have got them if I knew what I know now when I started. They should still be much better than stock rods. what rpm would you say is a safe limit for 3/8 scat rods, I read 6300 is the limit for stock rods with a 383.
 
Using 12 gauge wire I have loose rattling clearance on all block and piston spots. Placed the old factory cam in the block and hooked up the timing chain with a slow turn and stop, rod hits the cam lobe. So I either grind the rods for clearance or pay $330 for the rods I thought I had bought first time around. On the pics that show clearanced rods [ that look exactly like mine] that are ground across the rod not with the length of the rod as I was told to do and it looks like it is ground into the cap bolt. Now I can see that grinding the head of a bolt would weaken it but grinding the end of the bolt I don't see the same problem, although I am more inclined to listen to arp's reps than my own assumptions.
 
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