Seedy Al Posted May 9, 2016 Share Posted May 9, 2016 interested to see what happens here Quote Link to comment Share on other sites More sharing options...
Hemi Posted May 9, 2016 Share Posted May 9, 2016 Iunno , that crack goes a fair damn way down that thread. However id give the rebuilders the benefit of the doubt, unless it means more business for them later. Im still of the opinion that the issue we want to concentrate on is the lack of compression yeah?I want to see the pistons so bad just so we can X or not. Quote Link to comment Share on other sites More sharing options...
BlownCorona Posted May 9, 2016 Author Share Posted May 9, 2016 Yeah it really want to see the crack and pistons in person too. It's probably my aircraft background, but cracks are always a big nope in my book. Quote Link to comment Share on other sites More sharing options...
AllTorque Posted May 9, 2016 Share Posted May 9, 2016 With the crack being both sides of the head bolt hole, could that change the amount of pressure the bolt is pulling on the head? Have you checked the block deck for straightness, as Al suggested? Quote Link to comment Share on other sites More sharing options...
BlownCorona Posted May 9, 2016 Author Share Posted May 9, 2016 it will be checked asap along with the pistons. the engine is at my dads place hence the slow moving of this thread. but the help is greatly appreciated! Quote Link to comment Share on other sites More sharing options...
RUNAMUCK Posted May 10, 2016 Share Posted May 10, 2016 Was the replacement head gasket popped upon removal? Quote Link to comment Share on other sites More sharing options...
BlownCorona Posted May 10, 2016 Author Share Posted May 10, 2016 not that i could see, and the original gasket didnt look too bad, though im not well versed in all the ways a head gasket can blow. Quote Link to comment Share on other sites More sharing options...
BlownCorona Posted May 14, 2016 Author Share Posted May 14, 2016 cracked pistons (ring lands) pictures to follow shortly when they come through Quote Link to comment Share on other sites More sharing options...
Hemi Posted May 14, 2016 Share Posted May 14, 2016 Yus!! Shit news but. Quote Link to comment Share on other sites More sharing options...
kyteler Posted May 14, 2016 Share Posted May 14, 2016 Perfect time to put a good motor in instead of a Z-series. 1 Quote Link to comment Share on other sites More sharing options...
tim13 Posted May 15, 2016 Share Posted May 15, 2016 depends what events you want to run though , that car has run in a few 'classic' events which it could still do with a Z or L or FJ motor but only two of those can be done cheaply ...... if you are not worried about classicness or datsun-ness there are some great options out there too . but for me I would go Z based as best bang for buck , no fabrication , classic option Quote Link to comment Share on other sites More sharing options...
BlownCorona Posted May 15, 2016 Author Share Posted May 15, 2016 pistons 2 and 3 are pretty cracked. didnt get a chance to pull #4. but im expecting it to be alright like #1 is, due to the similar compression readings. the bores still look perfect so no issues there thankfully. the crack in the block goes down roughly 8mm and although im uneasy with the call, the engine shop rekons it would be alright and they see it often. i think dad is going to take some detailed pictures or maybe the whole block in to them to look at. i believe the current plan is to chuck replacement parts at it and get it back on the track running the same gear as it has for years previously. possibly get a checkup on the tune. Quote Link to comment Share on other sites More sharing options...
Grotty Posted May 15, 2016 Share Posted May 15, 2016 pistons 2 and 3 are pretty cracked. didnt get a chance to pull #4. but im expecting it to be alright like #1 is, due to the similar compression readings. the bores still look perfect so no issues there thankfully. the crack in the block goes down roughly 8mm and although im uneasy with the call, the engine shop rekons it would be alright and they see it often. i think dad is going to take some detailed pictures or maybe the whole block in to them to look at. i believe the current plan is to chuck replacement parts at it and get it back on the track running the same gear as it has for years previously. possibly get a checkup on the tune. I would not use that block 5 Quote Link to comment Share on other sites More sharing options...
RUNAMUCK Posted May 15, 2016 Share Posted May 15, 2016 I agree. Since he needs new pistons, if a replacement block needed an overbore it's no biggie. Quote Link to comment Share on other sites More sharing options...
fuel Posted May 15, 2016 Share Posted May 15, 2016 if possible - fit pistons with thinner compression rings and a wider gap between the rings. The older style pistons with thick rings and a narrow ring land gap are more prone to cracking like this. Quote Link to comment Share on other sites More sharing options...
RUNAMUCK Posted May 16, 2016 Share Posted May 16, 2016 Most modern turbo pistons are stronger. Wide rings help transfer heat from the slug into the bores. Super skinny rings areless prudent on a forced induction motor Quote Link to comment Share on other sites More sharing options...
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