High Compresion EA82T is now in my car

[mdjdc]

Over the past few weeks I built a new turbo engine with na pistons for higher compression. Mind you, the engine came straight from Japan and has zero miles on it. I tore it down to the crank and retorqued every bolt as the engine had been taken down by some kids at a tech school. I replaced all of the gaskets and I'm running stock boost and fuel management. I only have 35 miles on it so far, but it runs very well and I haven't really gotten into the turbo yet. I'm going thru a normal break in period due to the fact that this engine has had no run time until now. In 500 miles I'll let you know how it runs. The main reason for the swap is to increase my mileage and better low end off road. I love to take my kids out and bury the car in mud. They love it too.

 

Just wanted to share my project with everyone.

[Turbone]

Keep us updated. What brand of head gaskets did you use?

[GeneralDisorder]

NA as in? Carb, SPFI, MPFI pistons?

 

EA81 carb pistons are 8.7:1

EA82 carb pistons are 9.0:1

EA82 SPFI/MPFI pistons are 9.5:1

 

EA82 stock turbo pistons are 7.7:1....

 

GD

[[HTi]Johnson]

You know everyone is using higher compression blocks for their turbos...I say just push more air into the turbo block:headbang:. But those damn head gaskets!

[mikeshoup]

You know everyone is using higher compression blocks for their turbos...I say just push more air into the turbo block:headbang:. But those damn head gaskets!

Two things come to mind: Head gaskets, and low end torque.

 

High compression ftw.

[mdjdc]

I used spfi pistons. The low end is much better and with ernesto coming thru here yesterday I may have to go play in the mud on Monday.

[GeneralDisorder]

Watch your guages and such carefully - many have come before you, and none have suceeded. Off the top of my head I can think of at least 4 or 5 members of just this board that have tried it, and the usual result is either cracked heads/blown gaskets, or catostrophic piston failure - ring lands collapse, etc.

 

Good luck!

 

GD

[mdjdc]

I read a thread by someone who had 20,000 on a motor built like mine, but not a brand new motor. I'm hoping that the newer components will help it to hold together and I don't plan on pushing it too hard either. I just wanted better mileage and better low end torque.

 

I may be wrong, but I think I read that others were using additional boost with their high compression engines.

 

I am only using stock boost, but if you think lower boost is better I may think of putting in a boost controller so that I don't blow the engine.

 

I'll let you know how things go as I only have 100 miles on the engine at the moment.

[mikeshoup]

I'm using stock boost on my high comp motor btw. I did blow a headgasket in it. I'm not too sure how many miles had been put on the engine since it was built (I didn't build it). Just, be forewarned.

[mdjdc]

Were you hard on it and how many miles before you blew the HG?

 

Just asking.

[GeneralDisorder]

Being that the *normal* EA82T's blow head gaskets if you so much as look at them cross-eyed, the extra combustion pressures of a 9.5:1 turbo motor are going to be extremely hardcore on the gaskets. I definately wouldn't go over stock boost, and I might reconfigure for 4 or 5 lbs instead of 7. A lot of the aftermarket supercharge kits for various NA engines put out around 4 lbs. I remember my friends Audi was that way - you can get a blower kit for it ($3500 ), and it adds around 75 HP to his engine on 4 lbs boost.

 

Did you use the OEM gaskets or the Fel-Pro's?

 

GD

[TheSubaruJunkie]

I've been running SPFI pistons in my RX for almost 3000 miles now. No problems other than boost problems, maybe thats why its still running. I just fixed my boost problems (thanks to a broken up-pipe) and been driving it pretty hard lately.

 

-Brian

[subiekid]

I have been running EA-82 carbed pistons for over a year now in my 86 wagon. I have only put about eight to ten thousand miles on it, but they have been very punishing. The car has the stock VF7 (for now...), wrx intercooler w/ scoop, blowoff, no cats w/2'' pipe and a magnaflow. Head gaskets are also from napa. I have ran a consistent 12 lbs since I put the motor in and the clutch has been the limiting factor since day one. Other than going through a few turbo's the engine has been doing ok. It still runs fine, but you can tell that I have rodded the crap out of it. The rings were suspect on the block before it was turbo though, I had the block origionally in my 87 carbed wagon and it used a little oil. Anyway, just thought I would share my experience.

 

Scott

[[HTi]Johnson]

I think the IC is a big player in the longevity of a high comp block. Nothing like pushing super heated air into the high comp engine (or any engine). The IC is a good step towards lower combustion temps which means your head gaskets should last a little bit longer.

[Phizinza]

What you need is laser cut copper head gaskets, the type they put in some race cars.. Probably expensive, but very hard to damage.

[daeron]

What you need is laser cut copper head gaskets, the type they put in some race cars.. Probably expensive, but very hard to damage.

that sounds like about the sum and total of a turbo ea-82.. or ANY ea-82 really..

 

i mean, am i right??? ive learnt alot about cars thru this car and this forum and the last four months... really, its been a cementing or maturation of what i already knew (i DID keep a 75 EFI datsun 280Z on the road for 5 years and about 70K miles, before i got my soob, for the record) so, correct me if im wrong... but that seems to sum up the motor.. if we had some really good, solid head gaskets.. then we could make the engine cooling (thru two row rads, and oil coolers even) and the air cooling (for the turbos) to make ALOT of power out of a 300K mile (500K km) engine!!! well, alot for a 2500 lb compact sedan/wagon at least!

[GeneralDisorder]

People have tried copper, and failed. They are notorious for sealing issues.

 

The one thing that no one has tried (that I know of) that seems to be the best option, is to o-ring the block. That along with some serious hardcore pistons, high quality head studs, and fuel management would likely do the trick.

 

Subaru got the EA82T to push 175 HP for the rally spec version. They had all the parts availible to do it. I've seen some scans of the parts listings, and parts of the assembly instructions for them.

 

GD

[NorthWet]

Warning: Sacrelige (sp?) ahead!!!

 

After staring at some blocks, heads, and blown gaskets, I am beginning to believe that the design and quality of the head gaskets aren't the problem. I think that there are head/block mating surface issues and cooling system design issues. I think that if these issues were addressed the HGs would last even under lots of boost.

[daeron]

mating surface issues?? what might exist that a proper milling would not alleviate? again, searching for enlightenment :cool:

 

and what do you think of the cooling system? ive never seen this motor apart at ALL (and ive seen several different datsun, chevy, ford, outboards of all sizes, lawnmower, generator etc.. engines TOTALLY dismantled, and assisted on numerous engine rebuilds... just never been the one "doing" it) so im curious.. your post was a teaser. youre just baiting someone to be like, "Unh uh!! soobs RAWK and u r DUM!!"

 

what do you think of the cooling system? is it related to the high point between the "sides" of the engine you were discussing? that could be routed around, couldnt it? im picturing a retrofit of a different radiator here... maybe a three outlet rad, and retrofit the t-stat housing like one on an RX-7 (all i could think off offhand) that has the radiator cap on it?? that would get rid of having to "burp" the engine...

 

something tells me theres gotta be a fix, between ALL of our ideas....

[GeneralDisorder]

The water jacket in the head is weak, but with proper management and exhuast temperature sensors, and cylinder head temp sensors it wouldn't be a real issue.

 

The mating surfaces are fine - the bolts are the weak part. Can't torque them enough. Need some good studs, but at $700 for a custom ARP set, no one is jumping up to grab them. And the mating surface sealing issues largley go aways if you o-ring the block. Then you can just use standard head gaskets. The block o-rings are like a magic bullet for this whole gasket/sealing issue. But still have to work on the bolts/studs, and decent pistons.

 

GD

[daeron]

yah o ringing is kind of a no-brainer but youre basically saying, that they are basically just a weak point that deserves thorough monitoring... and given a good positive seal, and strong, solid, unstretchable fastening, you should be OK.. you just need to be told sixteen ways to sunday that you arent low on coolant

 

I am having some ideas.. my car has really bad rust, and the worst parts are around the trunk. the rear quarters are flapping around in the wind... being held together with paint. we are talking bad here.. and then theres the holes at the bottom corners of the rear glass. i can reach in them, thru the trunk, and wave thru the speaker holes. SO "fixing" any of this... is an outrageous project, and its gonna be jerry-rigged. now, add to that the desire that I have had since I was 13 to build a car that ran on LPG.. and add to THAT the fact that i just met LPGSuperChargedBrumby here on the board... and that i just learned its *essentially* just adding a venturi to my TB to make my ea-82 do it..... and i am already doing research on exactly how much beyond that it would take. obviously, I would be removing my gas tank.. and i would need a place for my new fuel tank. so the LPG conversion requires a re-engineering of the trunk/rear portion of the car anyhow. in a way, the repair the car needs justifies the LPG conversion, and vice versa. while im at it, im at LEAST looking into supercharging it (the idea occurred to me, i couldnt tell you why.. ) but none of this will be for AT LEAST a year. ive got a datsun to work on. SO anyhow, the soob gets to be the ho hum DD for now, and either get replaced once the datsun project is over... or continue to be my car. if i keep it, it needs to be fixed... but i cant imagine actually doing all that work on this vehicle. more likely ill keep my eyes peeled for another GL/loyale to buy and make one car out of the two.. i like having the sunroof tho, and thats not easy to find..

 

gee, sorry about that.. but my point is, im trying to evaluate what i really think _i_ can do with this engine, so im curious.

[NorthWet]

Although I personally would LOVE some affordable studs, I don't really think that the headbolts are the weak link. Datsun/Nissan uses similar size bolts (and Toyota, probably) and have virtually zero headgasket issues. (Datsun L-series engines use 43 ft-lbs head torque; less than the EA82...) I feel that if there is a weak link with the bolts, it is in the block threads pulling out. Daeron, do you happen to know what the Turbo Datsuns/Nissans use for headbolts, and what tightening torque they get? (Sorry to keep equating EA82s to other engines, but these are contemporary engine designs.)

 

I would REALLY like to know how many disty-side HGS blow out solo (not along with non-disty side). All of the single HG failures that I have seen (not that many, admittedly) are on the non-disty side, which I believe (really need to do a full teardown ) receives its coolant flow through the small port at the TOP of the engine case. Low coolant level means little/no coolant flow to non-disty side. Daeron, yes there are ways around this, but I think that it would entail external coolant lines to the N-D side.

 

So which side blows HGs more would be good to know.

 

Something else that would be good to know is the WAY in which they blow; the ones that I have seen have blown outwards into the adjacent coolant passages. They don't seem to leak inwards (up or down) along the broad area of the mating surfaces near the intake and exhaust passages. This makes me think that this thin width of gasket is just getting pushed out of the way and into the coolant passage; if these gasket sections could be stabilized it would be less prone to fail. I have some ideas for gasket stabilizing/reinforcing, but I think that the first step are freshly milled heads and blocks.

 

Another thing that I have noticed is that the coolant passages don't really match between head, gasket, and block (at least on the MPFI/turbo engines that I have looked at). One glaring mismatch is that the block has a coolant passage that is aimed right at the MPFI's exhaust port divider (common crack point) but the head does not have a passage there; looks like the passage could be drilled, and I have a scrap head that I will use to explore this.

 

*edit* - Daeron, I am not trying to tease or anything. I have some ideas, turning them over in my mind to see if they make sense and are the best way of doing things or if they are likely to really screw things up. "Better to be quiet and thought a fool then to speak and remove all doubt."

[daeron]

So which side blows HGs more would be good to know.

 

Something else that would be good to know is the WAY in which they blow;

 

 

I smell a sticky... SERIOUSLY.. lets get something together. I have a headgasket problem right now, im bubbling into my coolant almost constantly, but its a slow loss of coolant.... and i bet cash money its the non disty side, now. as many headgaskets have blown on EA-82s, its gotta be as important as the ea-81 vin#/hydraulic lifter question.

 

anyhow, i will look up what torque the turbo cars use, but i suspect it is very similar to the NA. there are ALOT of bolts on those motors, thats why i love datsuns so much.. theyre put together. my uncle (uncle buck, ) has been building high comp datsun OHC motors for YEARS and typically goes to about 55 ft lbs on his head bolts.

 

My thoughts on the coolant... what about splitting the output pipe from the water pump... and fabbing a manifold to return the water from the outlet on the dist side over into the tstat housing? im sorta picturing "twice pipes" here.. i think the alternative would be to run external plumbing that simply eliminates the high point in going over the bellhousing... i HAVE to look at my motor tomorrow without the spare in. ive had some interesting ideas here.. alot may not come to fruition in the near future, but i LIKE the ideas and i have time to chew on them. that OFTEN bears fruit in the end. lets keep this talk up, i like it

 

EDIT

heh, i was jokin around.. i hear you on the talkative fool.. (trying to integrate that into my life now, have you noticed i have a tendency to jaw?) i just think better in the midst of discussion. more comes out of my head, and frequently more comes out of the minds im around, too...

[NorthWet]

The EA82 uses more headbolts than the Datsun L-series, and more concentrated around the blowout areas that I have seen. And there is no "waterpump outlet pipe"; it has an inlet pipe, then its outlet is through the case.

[daeron]

heh, i tried to picture it in my head, and i just put the outlet at right angles to the impeller housing like the outlet of a turbo.. its late, im on the east coast, too.. you know how late it is. i need to sleep now, thats what that tells me. and i DID say i needed to look long and hard at my engine tomorrow. once i do my headgasket, i will know this engine much more thoroughly.. tearing something apart and putting it back together is such a great way to see how it works....

 

and i guess its just the iron block then... and at least they put more bolts in the soob than i thought.