project89

iTrader: (1)

so my current 355 engine has developed a rattle/knock that comes and goes, the car is currently at my friends shop waiting for me to head over this week for a teardown/diagnosis

my friend has donated 3 engines to my go fast for cheap cause , as he has a ton of cars/trucks and just built himself a megasquirt and picked up a few turbos. so he wants to see what i can do with a pile of parts, before he attempts it


anyways the motor in the car is a 4 bolt main 0010 block punched .030 over factory forged crank , recon stock rods with arp bolts , speed pro popup domes forged pistons , mildly ported/cleaned up 882's gasket matched tpi , summit 224/224 cam

few days ago car was running just fine took my wife to work then went to work myself , driving the car like a normal human , didnt beat on it or anything .went to run home for lunch and started the car up , engine fired and knocked a few times them stopped knocking , the knocks were completly random and not constant , drove the car home very easily and when i pulled into the driveway it started to randomly knock again then quit again suddenly

the following day i fired the engine and it didnt knock at all so i made the 5 mile drive to my friends shop about halfway there it started to knock bad and constantly so i kept rpms as low as possible and continued out to the farm knowing any damage to the engine was already done

about 1/2 mile away the knocking stoped so i pull into the shop drive it up on the lift and its running just fine , even reved the motor a few times and couldnt make it knock anymore

on monday im going to pull the valve covers and intake and insect the rockers/rocker studs and cam and if i dont find anything ill yank the heads and pan

the engines he donated to me are as follows

a sbc 400 std bore std crank , needs hone/rings and bearings has a set of unported 882's 2 bolt block

engine #2 is a perfectly running 72 4 bolt main truck engine that he just pulled out of a truck heads are 993 casting

engine #3 is a late model 1 piece rms 350 tbi truck engine block is setup for roller cam but has a hyd flat cam in it from the factory

my best case senario is my current engine is saveable with minimal work in which case ill reuse everything , all new bearings and swap the cam for a comp xe268h and fully port the 882's

i already know with my luck the forged crank is prolly hurt and cant be reused so i end up using the cast crank out of the tbi engine

third option is just just run with the 72 truck engine but ive been told the 993's are worse then my 882's so id prolly swap the heads and then cam that engine

4th option is to use the late model block pick up a decent crank bore the block and reuse my speed pro forged pistons and put a roller cam in it
this is the most expsensive option


thoughts opinions?

AlkyIROC

The both 882 and 993 castings are poor but if I had a choice, I'd go with the 993's since they are a heavier casting and less likely to crack. I'm not sure where the 882's every got a good review but they're the best of the worst heads and everyone seems to think they're a good head to use. The 993's are a heavy casting smog head. Not great for performance (very few if any smog heads are) but cleaning up the ports, installing bigger valves and using a dome piston to increase the compression ratio is a better investment than using a head that's prone to cracking.

Since this is a turbo engine, increasing the compression with pistons isn't required but a good casting should be. A turbo doesn't care if the heads have been worked over or not so just about any stock head will work.

project89

iTrader: (1)

probably because they were required for alot of dirt track racing classes (882's) and the fact they are the better of the smogger heads. i know they arent good heads but were the best of what i had,when i put this thing together there are also 2-3 versions of the 882's with one version being a heavier casting which i believe mine to be

i raised the compression for better off boost driveability and quicker spoolup

i did manage to lookup the 993 heads and seen they were used on 350's and 307's on the 307 they aparenbtly had tiny valves , so if i went to drop in that engine i would pull the heads to make sure they were original heads and not something that somone swaped on the motor from a 307 with the small valves.

then of course i would port and clean them up


right now i guess my best course of action would be to get the 355 torn down and find out exactly what happened and whats useable and whats toast, my first thought was either the cam going flat or a rocker stud pulling out of the head but since the knock comes and goes really has me baffled at this point

only thing ive done to the car recently is an oil change a week ago and put 6 quarts of rottella 15-40 in it which is what i run in all my turbo engines without issues

if i stick with a hyd cam i think im going to switch to royal purple oil since it seems highly recomended for hyd flat tappet cams along with the rottela its prolly going to get to cold here for the 15-40 in late winter

Dakota W.

Do the 993's have hardened valves?

project89

iTrader: (1)

good point im not sure if they have hardened valve seats or not ill have to find out specially if i end up dropping that whole engine into the car

UnstableAviator

Sell it all and use the turbo stuff on a 4.8/5.3/5.7/6.0 (whatever you find) LS.


The Megasquirt and MSD6010 combo will work just fine for boost with the turbo.

It's 2013 man. Sell the SBC stuff and hang on...

Dakota W.

He's being given these parts by a friend. It would be really disrespectful to sell a bunch of stuff that isn't yours, not to mention I'm sure his friend is going to keep whatever he doesn't use for the tt build.

83 Crossfire TA

iTrader: (2)

Um... are you sure it's an internal engine knock? Those don't usually come and go unless they are heat realted, and that doesn't sound like what you have. It sounds like something moving around and tapping on something else, like your balancer ring is loose and occasionally slides around where it rattles against the timing cover...

project89

iTrader: (1)

exactly
besides the fact i have a half finished 427sbc i started builing last year for an x275 car just dont have the funds to finish it and it will make way more power then just droping in an lsx and whatever turbo

it sounds internal , its very loud and sharp sounds like a ball peen hammer hitting cast iron , tommorow im going back over to my friends shop so i can go over the engine top to bottom ,

im going to inspect the converter,flexplate , balancer engine accessory first, then pull the valve covers , and intake to inspect rocker studs valve springs rockers, pushrodsand camshaft.

and at that point if i still dont find anything ill be yanking the heads and pan

project89

iTrader: (1)

ive decided to not even dick with it , its comming out for a full rebuild

goping to have the forged crank remachined ,im replacing the domed pistons and bringing the compression down to around 9.2-1 to make it a lil more nitrous friendly

the summit cam is comming out for a comp xe268

any recomendations on a decent but yet affordable set of h-beam rods

83 Crossfire TA

iTrader: (2)

I've run across 2 that sounded like a very sharp noise like you describe, one showed up and went away, the other seemed to change with temp. One was a slipped outer balancer ring wearing a groove in the timing chain cover, the other was a cracked flexplate.

If it goes away I doubt it's internal

project89

iTrader: (1)

It wasn't internal. Bad engine mount was making the steel charge pipe. Bang against the wonderbar . Stuffed a rag in there and no more knocking. Still using this as an Exscuse. To swap cam positions n heads though. Going to drop on the 210cc pro comps on it

project89

iTrader: (1)

Dakota W.

Well, it sounds cool!

project89

iTrader: (1)

lol had to rev it up a few times and make sure it made no more funny noises, heading back over tommorow to yank the top end off the engine , and pull the block.

going to cut the x-member and weld in a removable piece to make removing the oil pan in the car easy

while the shortblock is out ill check all the mains and rods and see how there holding up , swap out the pistons if i can find a decent set of h-beams , and swap the cam

if i cant find a set of reasonable h-beams and pistons im going to leave what i have in it and drop procomps on and leave the compression alone , maybe just switching to the aluminum head will be enough to run the nitrous on it with the same cr

Dakota W.

I had to use adjustable pushrod guideplates with my procomp heads, and shorter bolts for the 4 middle intake manifold bolts, but other than that they're fairly easy to do heads.

project89

iTrader: (1)

picked up a sb 400 last weekend .020 over with forged 15cc dished pistons
going to freshen the engine drop the procomps on it with the xe268 and let her fly

the 355 is going in my truck

project89

iTrader: (1)

since i put up that lame video heres a better one

2nd to 3rd gear 15/20ish roll to just over 100 , lol real sloppy 2-3 shift as i was juggling the phone sterring wheel and shifter

8 psi of boost on 87 octane 3/4ish throttle

mw66nova

iTrader: (13)

why does this thing sound like it's got a cracked exhaust manifold or something?``

project89

iTrader: (1)

downpipes exit at the bottom of the firewall , and my turbo to downpipe flange was leaking, when i shot the video i wa son my way to my friends farm/shop so i could work on the ex system

edit

i think my downpipe flange on the passenger side is warped, every time i reaseal that with a new gasket it blows out again about 2 weeks later