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Road Race Enduro L28 Engine Build


z-ya

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We triggered the bonny engine from the distributor quill, using the small e-motive wheel.

 

As for the blocked water passage, there has been one guy here (ahem) talking about removing the internal bypasses back to the inlet of the water pump to maximize cooling flow through the block for some time now and (sniff sniff) he's feeling a bit put out that nobody has listened and immediately recognized another "lost performance cooling modification" for the L-Gata! That goes for the -3 AN lines as well. Take a look at the discussions on the #5 Cooling Thread and all will be alluded to, if not outright explained...

 

Some people plug the return in the block with a flushseal plug, but putting aluminum in there does the same thing.

 

Is it the same passage that Nissan plugged on the LD28 in the block itself?

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We triggered the bonny engine from the distributor quill, using the small e-motive wheel.

 

As for the blocked water passage, there has been one guy here (ahem) talking about removing the internal bypasses back to the inlet of the water pump to maximize cooling flow through the block for some time now and (sniff sniff) he's feeling a bit put out that nobody has listened and immediately recognized another "lost performance cooling modification" for the L-Gata! That goes for the -3 AN lines as well. Take a look at the discussions on the #5 Cooling Thread and all will be alluded to, if not outright explained...

 

Some people plug the return in the block with a flushseal plug, but putting aluminum in there does the same thing.

 

I'm listening Tony! I did that mod on the other engine.

 

I guess plugging the hole in the block might be easier. The other thing I noticed last night is that there was no thermostat in the housing, and the outlet from the thermostat cover has an aluminum washer welded to it as a flow restriction:

 

PB290027.jpg

 

Also, if you look closely at this photo you can see that the -8AN welded to the water pump inlet:

 

PB260025.jpg

 

goes to a coolant tank:

 

P1010040.jpg

 

Also note about the -3AN line goingfrom the same coolant tank to the other side of the engine and to the thermostat housing:

 

P1010042.jpg

 

The other side of the -3AN Tee goes to the top passenger side of the radiator:

 

P1010041.jpg

Edited by z-ya
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And all this is to keep the engine from over heating or is it about cooling the rear cylinders?

 

Pete I meant to ask you, what sort of progress rate are you looking at for this build? Sometime soon or a long term thing?

 

The car needs to be back together by May.

 

 

It also looks like it has a diesel water pump as it will not fit in another timing cover I have without the impeller hitting the timing cover.

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Update:

 

Head has been disassembled, checked for flatness, and pressure tested. All tested OK. My machinist is impressed with the level of work done to the head. It is basically ready to go. Titanium valves, bronze guides, each valve spring shimmed for correct pressure. The only thing that needs to be done is the cam towers need to be align honed. I need to decide on pistons before that can be done (need to know HG thickness and shim cam towers).

 

Here are some photos:

 

P9260017.jpg

 

P1010001-1.jpg

P1010013.jpg

 

Now I have a new set of these Cosworth pistons which I may use:

 

P9260023.jpg

 

But Cosworth can't find any information about them, so I need to measure the dome volume. So I blasted and painted the top of a used one, waxed it, and made an impression in fiber filler.

 

P1080015.jpg

P1080014.jpg

 

I'll cc the impression to determine the dome volume. Once I know that, I can:

 

- Decide if I will use them (CR??)

- Determine HG thickness

- Determine how much to shim cam towers

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Nice engine bits and pieces....good luck with the build.

 

Just a observation on that welded thermostat cover. The option of easily changing the restrictor is not there with the restrictor welded in.

 

If there is to be any testing of block coolant pressures after the build and it is determined that the restrictor needs to be larger, then I guess that's not a problem than if the restrictor needs to be made smaller. (This also ties in with coolant temperature, so a balance needs to be found here, harder to achieve with a welded in restrictor.)

 

I would have thought that a machined disc similar to the thermostat itself be used in that original position. A selection of restrictors could be made easily, with a range of hole sizes so that flow, temperature and pressure could be optimised.

 

Another way would be to alter the water pump speed with a variety of water pump pulleys but this would be more work and expensive to set up.

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I haven't decided how I will route the cooling yet. There wasn't a thermostat in the housing with the restriction.

 

Sending the cam, rockers, valve springs, and lash pads out for cryo treatment later this week.

 

Here are more pics of the Bob Sharp prepared E31 head I am using:

 

P1090021.jpg

 

P1090019.jpg

 

P1090018.jpg

 

P1090017.jpg

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And all this is to keep the engine from over heating or is it about cooling the rear cylinders?

 

You haven't been paying close attention... they go hand-in-hand Josh. What starts at the back of the head (read the cooling thread and what we found on the dyno last run) and carries over to the rest of the engine. You have to control heat at the worst part of the engine first, and the rest won't have an issue.

 

What pressure cap was on the radiator in the car Pete, 13, 16, 24, or higher PSI? B)

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You haven't been paying close attention... they go hand-in-hand Josh. What starts at the back of the head (read the cooling thread and what we found on the dyno last run) and carries over to the rest of the engine. You have to control heat at the worst part of the engine first, and the rest won't have an issue.

 

What pressure cap was on the radiator in the car Pete, 13, 16, 24, or higher PSI? B)

 

Didn't get any radiator caps with all this stuff. I know who to ask though :wink: . I'll also find out how all the -3AN lines to connected. I'm not totally sure at this point.

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pete, does this mean the bad dog will be renamed badder dog? if you wanted to make the dampers look pretty sitting on the shelf, send them my way and i'll get them yellow zinc plated for you, my treat.

 

david

 

No, the Bad-a**-Dog :D. Seriously, it will definitely have more power, but a lot of the work we are doing is to make it safer and conform to the vintage safety rules.

 

I may take you up on that offer!

 

Pete

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Very nice project, Pete, some great parts you've amassed. Where did you get all this authentic Bob Sharp stuff?

 

We know the person that purchased many of the cars and parts that Bob Sharp still had a few years back. He has since sold the 240Z that Paul Newman won the 1975 C production championship in. Since this was the only S30 he had, we made an offer to buy all the S30 parts he had. He just sold the Z31 turbo Paul Newman won two GT1 championships in. It's going out to CA in February to its new owner. He still has the 280ZX TT IMSA car and the Z31 Tom Cruise raced in SCCA showroom stock class. Both are for sale if you know of anyone with a big wallet and that likes vintage racing Zs.

Edited by z-ya
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