348 Tri-Power Build gone wrong / Follow New Rebuild

'37-4D

Well Known Member
One bright side to this fiasco is that you can have the engine rebuilt with quality components (forged) the pictures show that not only were the pistons cast but the low compression version to boot,it appears that the the shop that rebuilt the engine used one of the low cost rebuild kits.While they have their place for the typical low rpm stock grocery getter rebuilds,they're hardly the choice I would make for an engine intended for use in a hot rod.The stocker pistons for a 348 are still half the cost of a set of icon forged so they're not even very economical.It appears your block has the extra metal for the spark plug cooling holes if you should decide to upgrade to aluminum heads later your head gasket even left witness marks as to where you would drill them.I would scrutinize the itemized bill to see just what they charged you for and compare that to what is there if you can find significant discrepancies that may strengthen your court claims if you choose to pursue that route.For example if they charged you for chemical cleaning or bake and blast cleaning of the block you can easily show that neither one of those were performed.Even if the bill doesn't specify what type of cleaning was done if the charge is comparable to what other shops charge for that type of cleaning the standard has been set.
I will absolutely scrutinize the invoices. And make sure he didn't charge me for something that isn't there. Such as forged pistons when in fact he installed cast. Thank you for the heads up.
 

wristpin

Well Known Member
Does anyone else think the baked carbon buildup looks like many miles of usage not basically fresh? Soot or oil is one thing. Thats baked on buildup !!
 

'37-4D

Well Known Member
Looking back through your pictures you show the rear main cap, there is no rear main seal in it, did you remove it or was it not installed?
It was removed prior to the picture, but it was missing the tabs that go with it. I've heard that these are often omitted and the cause for leaks!
It wasn't mentioned by the new guys as missing.
 

'37-4D

Well Known Member
The crap fuel now days don't take long to do that, and I believe he has been going through some teething stages with the 3x2's
Do you think that with my smaller 971 heads and the 3x2s, it was running rich? did this have anything to do with the carbon?
Perhaps the 333s I just bought will help with that? I wanted 817s as Don mentioned but not easy to come by up here LOL
 

La Hot Rods

Well Seasoned Member
Supporting Member 15
I'm sure a lot of your tuning problems had to do the with the condition of your engine and the improper cam. You were dealt a bad hand of cards face down from the start and had no ideal that you should have folded from the start.
 

Tooth

Well Known Member
Supporting Member 3
Sorry for your situation, I am sure that if somebody asked me to build an engine for them I would’ve checked piston valve clearance and rocker arm geometry also would’ve used all the proper parts to build the engine. I don’t know what kind of a pro shop this was but putting a motor together to where the cam has enough lift that the Pistons hit the valves Is A catastrophic fail! Even if you gave them a budget and they run across this problem they should’ve raised the flag and let you know. And what kind of pro shop engine building apparatus would not clean the block and leave all that sand and grit in the oil galleys to kill your bearings? Just because it’s a W motor is no excuse because no engine build with live under those circumstances! Go get them and Hold them liable!:furious:gaah:mad6hold them liable! Keep us posted. And good luck.
 

Don Jacks

Well Seasoned Member
Supporting Member 3
From the looks of those pistons,sometime early in it's life that engine was run into severe valve float.The cam that I think he's using is close to valve interference,but still works unless over reved into valve float.The amount of carbon on those marks indicates a one time thing,not a constant contact issue.That could have been the start of the crack for number 6 as well.If forged pistons had been used these marks wouldn't have happened because they have valve notches.The bearings appear to be damaged from dirt.
 

'37-4D

Well Known Member
Sorry for your situation, I am sure that if somebody asked me to build an engine for them I would’ve checked piston valve clearance and rocker arm geometry also would’ve used all the proper parts to build the engine. I don’t know what kind of a pro shop this was but putting a motor together to where the cam has enough lift that the Pistons hit the valves Is A catastrophic fail! Even if you gave them a budget and they run across this problem they should’ve raised the flag and let you know. And what kind of pro shop engine building apparatus would not clean the block and leave all that sand and grit in the oil galleys to kill your bearings? Just because it’s a W motor is no excuse because no engine build with live under those circumstances! Go get them and Hold them liable!:furious:gaah:mad6hold them liable! Keep us posted. And good luck.
Thank you for this bit of info! I sure hope the new guys caught this and I'll be sure to relay any and all information I am getting here.
 
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