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Datsun B310 turbo coupe, A15 project


Atomic

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4 minutes ago, slowlearner said:

I just finished an aircooled VW turbo project. They need more oil for a turbo setup. Either with a bigger pan, a cooler or both. I did both because I live where it gets to 100F pretty regularly. I'm a little mystified why you'd need that cooler in Finland. How hot does it get there in the Summer?

 

P.s. I'm enjoying your build though. 🙂

 

I think I have pretty much maxed out the pan size at the moment, unless I would want to widen it and make it really hard to uninstall it, so I'll go with the cooler for the moment. Well, last summer it was 90F most of the time. But usually it's around 60-75F during the summer time. The turbo itself heats the oil quite a lot and turns it really thin, even when I'm just idling the engine. So the main cause for the oil cooler here is not the climate itself, but the turbo instead.

 

And I'm glad you enjoy it!

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There'll be that one time where you lean on your engine a little more than you usually do, like a long stretch, canyon carving or up a long hill. You build for this and you don't have to worry or let off. I switched to electric fans, two of them. They were on a Subaru side by side on a wider rad than mine so I fit one blowing inward on the front and one on the inside wired backwards drawing air in through the rad. They overlap about 4". Surprisingly the engine seems to run slightly hotter on the gauge, probably because the fan isn't on all the time like it was when it was mechanical. An oil cooler removes heat from parts of the engine that coolant never gets near as well as some that it does. I don't drive this in the winter so thick oil on start up isn't a problem and that's a new car problem anyway, not so important on older engines that are more robust built. 

 

It got to 94C once.  Usually in the low 80s on a warm day.

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Hmmm, sorry for my poor photoshop skills, but I was thinking about buffing the front lip a bit:

d_front_lip_by_atomicsickness_ddbyu6i-pr

Lip is taken from 240z for this picture, I wonder if the lip dimensions would suit my needs irl

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Got all the pieces out from the engine:

img_20190720_140212_by_atomicsickness_dd

img_20190720_140221_by_atomicsickness_dd

The Cam bearing surfaces looked a bit odd, some of them had this burnt smutch all over them:

img_20190720_140233_by_atomicsickness_ddimg_20190720_140246_by_atomicsickness_dd

It comes off with finger just nudging it off, the bearings were brand new and they had some installation grease when they came back from the shop that installed them. Should I replace the bearings or?? The first one looked kinda worn in my opinion, but I'm not sure. Quite strange.

 

img_20190720_140350_by_atomicsickness_dd

Main bearings on the other hand were superb and didn't have almost any signs of coating losses from the ceramic side.

img_20190720_140528_by_atomicsickness_dd

img_20190720_140612_by_atomicsickness_dd

And would you look at this ridiculous difference between the old and the new rods that are going in

img_20190720_144454_by_atomicsickness_dd

I should probably get the block surface ground a bit I think? Just to get the old stains out and there were some small ripples that could be felt with a finger tip.

 

Also changed the pistons size from 77 to 76.5 mm. I wanted to avoid thinning out the block too much between cylinders 1-2 and 3-4

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Do you know if the rod bolts were torqued to spec and sized?

When I was building my L block I bought similar piston rod combo....

H beam rods and wiseco pistons....

 

My engine shop torqued the bolts to stretch them and then resized the big end for roundness they also honed the small end for a better finish and to tolerance the wrist pin.... 

Just something to consider with the effort you putting into it....

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2 hours ago, Crashtd420 said:

Do you know if the rod bolts were torqued to spec and sized?

When I was building my L block I bought similar piston rod combo....

H beam rods and wiseco pistons....

 

My engine shop torqued the bolts to stretch them and then resized the big end for roundness they also honed the small end for a better finish and to tolerance the wrist pin.... 

Just something to consider with the effort you putting into it....

Yes, I torqued down to ARP spesifications, which are higher than the original ones. Haven't had the original ones sized, will be checking with the new ones tho

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I was thinking about oil jets to the A15 block. Maybe drilling M4 threads around here to hold the jet nozzle in place.

img_20190720_190819_by_atomicsickness_dd

img_20190720_190828_by_atomicsickness_dd

I would then drill holes from the side of the block and thread them so that I could tighten the oil jet to the block, so now I would have 2 mounting points to avoid it getting caught while engine vibrates etc. Why I'm taking the holes outside of the block? I have a fear that if I probe them from the main oil galleys, then there would be too much oil pressure drop due turbo + jets. So I would want to build a small pickup system from the oil pan with a small 12v pump just for the oil jets.

 

Why I want everything, and things are complicated? I just have a huge urge to try out all the performance modifications with this engine and push it to the limit (queue song) 😄 

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img_20190720_144454_by_atomicsickness_dd

 

Have the block O ringed and save yourself having to change blown HGs.

With all that extra oil fog flying around make a windage tray/crank scraper to separate it out and send down into the pan.

Oil jets will only lower the idle and low speed oil pressure. Once the pump is spinning fast enough to meet the demand the pressure will be the same as without. Definitely an oil cooler now.

 

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11 hours ago, datzenmike said:

 

 

Have the block O ringed and save yourself having to change blown HGs.

With all that extra oil fog flying around make a windage tray/crank scraper to separate it out and send down into the pan.

Oil jets will only lower the idle and low speed oil pressure. Once the pump is spinning fast enough to meet the demand the pressure will be the same as without. Definitely an oil cooler now.

 

I was thinking about O-ringing too, but I'm not sure if that's possible with the small width of the walls between cylinders 1-2 and 3-4. 

The windage tray is a good idea and I might know where I could position it, cheers! 

7 hours ago, datzenmike said:

There's an article in  Club 1200 about modifying an L series oil pump to work on an A series. Massive output.

And yeah, I think i stumbled across this once before in my build too. Doesn't seem to be that bad modification to do at home/machine shop. I have 2 extra bodies from old oil pumps that I could use as a spacer. It all comes down to where I could find a cheap L series oilpump. Most of them are outside of europe and shipping+import taxes make them crazy expensive.

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Got the pump sourced from Finland, it's from L18 motor. Gonna borrow some tooling and make the needed adjustments and modifications for the oil pump. Then I can probably just drill holes to main oil galleys and source the oil jets from there! 🤠

 

My only concern now is that how I will make the threads for the oil pickups so that they don't leak. Is normal threading sufficient or should I just go for some NPT threads. I need to think about also how I'm going to seal the oil path to the jet

Edited by Atomic
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I could use NPT fittings like these: 

s-l1600.jpg

And just run 3/16 brake hardline fitting and hardline near the pistons. And also drill the threaded holes to keep the jet in place near the cylinder.

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When you torqued the rod cap bolts to ARP spec did you have the big end honed to round again?  I've never used arp stuff but i believe they state you must machine the big end after torquing the bolts down to the new spec.

 

Also i believe there are companies who make some kind of "siamese" rings for tight cylinder spacing

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10 hours ago, Lockleaf said:

When you torqued the rod cap bolts to ARP spec did you have the big end honed to round again?  I've never used arp stuff but i believe they state you must machine the big end after torquing the bolts down to the new spec.

 

Also i believe there are companies who make some kind of "siamese" rings for tight cylinder spacing

That's a good point, because I didn't.

 

I will look into those rings later, just got one quotation from Machining company, waiting for couple of others too. 

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Hmm, second thoughts. The O rings only work on copper/titan etc gaskets if I'm not mistaken. Nobody offers 1mm thick gaskets for A15 as copper/titan/etc. And the closest ones that are 0.8mm, will cost over 200 euros? I might as well just try to keep the cylinder temperatures reasonable and avoid detonations so I don't need O-rings yet. Oil jets + E85 

 

edit: or when there is a metal head gasket for A15, they're for 79mm bore? Ach

Edited by Atomic
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atomic, for o ringing the block, use a fly cutter ground a hair thicker then safety wire. Cut grooves in the block where 1 n 2  and 3 n 4 intersect like 8s. Then its a mater of forming the wire to fit the figure 8 groove. when you put the wire in the groove its about .005" or so cant remember above the deck height and just use a stock head gasket. did this on our u20 after everything else failed including yamabond. that sht is hell to remove. I have a l20 block that we did that to but its late in the day to get a pic. Ill post pic when I can. cheers

 

 

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4 hours ago, datzenmike said:

Can you tap into the oil line that feeds the main bearings?

I think the main bearing lines are on the vertical plane and really hard to drill to location. Also the balancer swings really close to those. 

img_20190721_112455_by_atomicsickness_dd

 

Also figured out that the oil left in the cam bearings was still the assembly lube that wasn't worn out yet. Should it dissolve quicker?

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