Disaster...360 Engine blew a connecting rod

[chargerdon]

Ok $75 question.   My original block and the block i bought both have Head Bolts marked with 6 radial lines on the shorter bolts... Im certain that means Grade 8, and the longer bolts are marked with two crossed lines, which i believe mean "AN Standard Steel".   I believe all are stock head bolts.   

They all look in great shape.   the short bolts measure and measure from bottom of head to end between 1.824 to 1.853.   The log bolts measure from under cap to end 3.200 to 3.230.   Are these bolts reusable??????   New Arp bolts cost $74.99

Same question with the main bearing cap bolts...   Are they reusable?   Or do i need to buy a main bolt kit...$48.99 for ARP bolts at summit. 

[Brads70]

Considering where /what they have "been thru" and the costs involved I wouldn't risk it, buy new bolts, block will have to be align honed anyhow.....

[RUNCHARGER]

The bolts are reusable however the 4 head bolt per cylinder is a bit of weak point on an SBD. For the minimal cost I would buy new for both locations.

[jimynick]

It really depends on what use you intend to subject it to. There were lots of engines with 4 bolts per cylinder and unless you're running 12-13:1 compression or revving it to 8000rpm, it shouldn't be an issue if both heads and block are flat and true with a good gasket. Having said that, if you're easily worried, why not just buy a stud kit instead? 

[Chryco Psycho]

Heads studs can be problematic in street cars , often no way to lift the head enough to remove it in the car

[chargerdon]

Machine shop finished my short block and delivered it for me yesterday.   So, what i now have is a 72 360 LA cleaned and bored out to .030, all new frost plugs, new cam bearings, and both block and heads decked to true.   It has Scat forged crank and scat forged connecting rods and ICON dished 20.5 pistons.   (stroker to 408) Deck height of pistons is now .004 below deck.  With the 915 J heads with 2.02 intake valves, i calculated 9.7 compression using Felpro 8553 .051 compressed head gaskets.   My total out of pocket cost so far is $100 for the block and $2800 to machinist for all his work and the parts. 

The machinist internally balanced the rotating assembly so buying a new Scat brand damper and flexplate for internally balanced engine.   There goes another $190. 

I'm Reusing the stock pan from the $100 block as it looks good and i'm going to install a new Melling standard oil pump.   With everything new it should have good oil pressure.   My old oil pickup tube (for the deep 7 qt pan) no longer fits.   Just as well, as it wouldn't have cleared the #6 and #7 journals now that its a stroker...   So putting in a new standard Melling oil pickup tube.  Pump $45 and pickup tube $25.  Im reusing the Lunati Cam as is shows now damage, and the lifters again no damage.   Ill probably have to buy new push rods, as the engine previously was pushing  .080 prelift...   and with the decked heads and block...it might get to be too much.  But will see when i assemble. 

Throw in a Felpro gasket kit for $52, 5 qts of Driven brand break in oil, and 6 qts of Driven brand 10W-40 oil (both have the zddp additive in it and two filters and there goes another $100.

All told it looks like:
     $100 block
   $2800 rotating assembly parts and machinist work
   $   52 GASKET KIT
   $   75 Oil pump and pickup tube
   $  190 Scat new Damper and a new Flex plate.
   $  100 oil and two filters
   $    30 RTV sealants
   $  200 Taxes
Total  $3400     and counting

Starting the assembly Friday (6/21) morning..and will be taking my time..  Buddy of mine will come over to degree in the cam just to make sure...i expect to find it right on! 

[jimynick]

Looks good! Why the thick head gasket? What difference in CR does a normal .039" gasket make? I've read lately some concerning stories about thick head gaskets and sealing (primarily water) issues. Don't forget to check valve to piston clearance as well as rod big end to block clearance. It should be awesome; make sure you post a vid of it running when that day arrives! 

[Chryco Psycho]

i agree , I would use the .039 head gaskets , you will have perfect piston to head clearance
otherwise it looks great 

[1 Wild R/T]

i agree , I would use the .039 head gaskets , you will have perfect piston to head clearance
otherwise it looks great 

He has open chamber heads so not really....

And while on that subject Have you actually CC'ed the heads? Cause typically 915's come in around 70-72 cc range & with a 4.030 bore, 4.0 stroke, .041 gasket, 20cc dish & .004 deck height you will be at about 9.2

Which is pretty decent considering you running iron heads & no quench.... 
A swap to 63cc Edelbrocks or similar will put you right at 10.0  with quench & Aluminum heads so completely safe...

[Chryco Psycho]

well with the piston .004 below deck & .039 gasket you don/t want to gt much closer , understood there are open chambers & I know he cannot step up to alum heads so as good as you can get with the parts he has

[1 Wild R/T]

I agree, but the perfect piston to head clearance comment to me implies quench which unfortunately ain't gonna happen but at 9.2 he shouldn't need it... If he somehow truly has 9.7 then he could sure use it.... 

And if down the road he can swing a set of aluminum heads the 20cc dished piston will work well giving quench & a great C/R....

[chargerdon]

Heads were CC'd before they were decked at 65 cc...  after decking probably at 64.5 cc...   machinist said they were very close so didn't take off much.

The Felpro 8553PT gaskets come with the kit...  So, i don't really want to spend more than i need to, but.. 

Its kinda crazy as different opinions on what their compressed thickness is...It isn't listed in the overview.    I know that on summit Q&A on compressed thickness says three different answers...  high of .051 measured from old gasket, to .039 from Felpro.    I know my blown engine also had the Felpro 8553pt gasket and it measured .051...But i dont know how much they expand when removed versus clamped down.....   the new ones uncompressed measure .059.    With heads at 64.5 cc .051 will give me 9.7 while .039 would give me 9.89.   PS...their inexpensive and came in the gasket kit i bought...The salvage yard block i bought also had those gaskets and they looked rock solid removing them...

i found this on felpro forum:

11-04-2014, 04:56 PM
Ryan
The thickness of this gasket is 039″.
Hope that helps!
Thanks!
John
Fel-Pro Team Member

Felpro also says simply measure the gasket..not on the ring but anywhere on a flat surface...ok...i get .054  they say that it will compress between .004-.006   so using .005 that would give me .049 compressed..  and that would give me 9.7 compression ratio...   With the iron heads i think that is a good number...  maybe next year put on a set of aluminum...   running out of funds and might have to spring a lot for possible surgery on wifes back...just spent $1500 out of pocket for MRI...   

Anyone know for sure?   As i'm about ready to start installation.. 

[Chryco Psycho]

You have them , might as well use them .010 is not a lot of difference

[chargerdon]

Put on one head using the Felpro 8553pt gasket.   Measured my preload on my push rods and its too much...(on the old engine i had measured preload of .080-.085 which is higher than Lunati recommends, but, when i called Lunati they said higher than optimum range of .020-.060 but that they would be ok...that chrysler routinely set their preloads at close to .100 anyways. 

Best measurements i can take on this engine the preload comes out to around .120-.150.   Lets call it .135   The pushrods are 7.600 length 5/16 .080 wall thickness.   and have open ball ends so that it is for "oiling".    So, if my math is right 7.6-.135 = 7.465 with no preload...put in .040 preload and i need 7.5 length pushrod.   For some reason summit is messing up and Jegs doesnt list all that many diffferent brands.   Advance and Autozone only show pushrods with balled ends that would have no oiling.  Can someone help me with a part number for pushrods .1 inch shorter than what i have...   I.3 7.5 5/16 oiling pushrods?  Part number please ? Least expensive if you dont mind.   Thanks..

[Chryco Psycho]

On an LA engine the oiling is through the rocker shaft Not the pushrods , being hollow makes them lighter . You can order them from Smith Bros in Bend Or , they will have them for you overnight as an option or you can use Autozone type