Re: Trying to find out about a piston

cobrakid8 January 24th 2018, 2:12 pm

Paul Kane wrote:
cobrakid8 wrote:Well, Arias were finally able to find the card for the pistons and crank as they were custom ordered:

stroke on crank is 4.15
bore is 4.47 with .009 piston to wall built in
rod 6.780
BH 10.295
.990 Pin
CR 13.0

5/64x5/64x3/16 rings

There is a small issue of note here, not necessarily a big red flag but noteworthy of a heads-up:

5/64" ring sets are essentially non-existent as a shelf-stock item in 4.47" bore (on paper anyway), so it may (or may not) be necessary to call a ring manufacturer directly and ask them to put such a set together for you. If you were running a blown gas 1500 hp competition racing engine your routine ring change-outs could get expensive. Fortunately, as a recreational bracket racer with a naturally aspirated engine that won't be the case (although the initial cost of buying into a custom ring set will probably be more than typical). If you special order a 5/64-5/64-3/16 ring set in 4.47" bore then I suggest you by 2 sets and then inspect (leakdown) & replace rings individually on an as-needed basis. 2 ring sets should easily last you several seasons with the racing you describe, and much longer (if not forever) in a street engine.

As an alternative to the above you can consider the following: JE offers a shelf ring set J85008-4468 which is for a 4.468" bore, and is made up of 2.0mm-5/64"-3/16" rings. That 2.0mm top ring is essentially the same thickness as the 5/64" rings (the difference is a few tenths and well inside any piston's ring groove tolerance).

Don't be discouraged as this is not a problem it's just an inconvenience, and one that you will have to address only on rare occasion. By the way, check with Arias first and see if they have any such ring sets on the shelf.

_______________________________________

Paul, for now I only plan on running it one season, hopefully and i know this sounds bad, but hopefully Tyler can make enough rounds to make a little bit of money and if that happens it will be time to go to a A460 or aftermarket block along with 4.5 crank with steel rods. We have never ran aluminum rods in a motor and they kind of scare me, and although they are brand new they are most likely very old new, so one season and hopefully it will be easy enough to switch to a bigger motor and some other changes. My biggest reasoning for trading for this motor was the A460 heads and matching intake, the block being half filled took away a little trepidation I had on the bore being to much and even though its a little smaller 4.470 compared to the 4.500 i was told it should live to see a season or so before I move up towards more like a 572 or 600 inch motor.

So does anyone want to take some guesses on what it should run and maybe HP? I dont really have a chance locally for a motor dyno so not sure if i will ever be able to get it done but below is the specs for the most part:
4.470 bore arias pistons with 6.780 aluminum howard rods with Howards ARP bolt upgrade
4.15 Stock offset ground crank
1.7 steel rockers(always ran aluminum so this will also be different but they look brand new as do the springs)
cam I havent been able to confirm just yet but the cam card i found online looks like duration 304/310 @.050 270/276. gross valve lift .722/.722 LSA/ICL 110/104
pushrods are 9.080 and 9.100
older FMS A460 heads and matching intake(doesnt really look like much porting done except maybe for matching purposes).
Headers are the ones off the dragster chevy exhaust but i havent measure them yet on how big they are, but did put them on the other night and they fit perfect
CR should be 13/1 and the carb a 1050 holley on gas for now, havent decided if i want it on gas or alcohol and if a 1050 is big enough or not

i would say car is 2000 or less with the 150lb driver
powerglide with 1.80 straight cut with pro brake, 5500 stall converter
4.11 rear end gear with 33/16/5/15 Hoosier tires

cobrakid8 January 31st 2018, 6:51 pm

So besides HP estimate would anyone be able to tell me if a 1050 or 1150 would work better on this motor? I have the 1050 gas carb and just wondering if I should sell it and go with a 1150 and not sure if doing gas or alky

Colt Macara February 1st 2018, 1:20 am

cobrakid8 wrote:So besides HP estimate would anyone be able to tell me if a 1050 or 1150 would work better on this motor? I have the 1050 gas carb and just wondering if I should sell it and go with a 1150 and not sure if doing gas or alky

CK8, Just my opinion. I think you should start with the 1050. My thinking is you can always move up after you get a few passes under your belt. If you sell the 1050 for the 1150 and find you lost some velocity or even a little torque, it is harder to go back to find out you made a mistake. Of course one way to limit the assumption is maybe a half day of dyno time. JMO

Colt Macara February 1st 2018, 1:28 am

I still think you are going to be around 725 HP. The big 2.350 valves are there, but without some good port work it is a mute point. I think you would probably gain 60 HP with the "Charlie" port work on the A460's then maybe the 1150 would be more beneficial. Have to remember your pump is still a 521.

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