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3.1L Project.. looking for recomendations


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OK, so I have been doing lots or research and reading in getting prepared for my upcoming project... but it appears that the thoughts on this site are different and i was going the wrong way...

 

So here's the plan: 72 240z, 3.1L

 

I have access to the diesel crank so that made my decision on this project easy. I know this is not an easy projcect and there is alot involved, and i know its going to take alot of time and money to be done right.

 

so i know i have to start of with the L28 engine, LD28 crank, 240sx pistons, and i have head about boring it 3mm over bore, and getting the 9mm connecting rods from the 240.

 

from what i have seen there are lots of head combo's out there to choose from..

 

so with regards to the starting point.. any recomendations for the base engine to start with.. will any L28 do?

 

thanks

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It sounds like you have done a bit of reasearch and you most likly will do more. What I have found out, is that it is best to have a expert Nissan engine builder at hand. I am not an expert. So my friend that is an expert Nissan engine builder is building mine. Of course the desired outcome needs to be considered, street/race. I can tell you what mine will have; I can't rember the block but I think it is a F-54, Vo7 crank, 240z 9 mm. rods, Nissan Hard Body Truck 89 mm. pistons #12010-86G20 that need to be machined according to compression ratio, Nissan piston rings #12033-86G00, Nissan comp head gasket #11044-91MM1, Head is an E-88 with enlarged seats and valves with port work, custom grind cam, TWM intake with tripple Webers. My understanding of this motor is to find the best machine shop possible, hopfully one that has done work on a 3100cc before. The ballance job is critical.

My parts went to the machine shop 3 days ago.

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It sounds like you have done a bit of reasearch and you most likly will do more. What I have found out, is that it is best to have a expert Nissan engine builder at hand. I am not an expert. So my friend that is an expert Nissan engine builder is building mine. Of course the desired outcome needs to be considered, street/race. I can tell you what mine will have; I can't rember the block but I think it is a F-54, Vo7 crank, 240z 9 mm. rods, Nissan Hard Body Truck 89 mm. pistons #12010-86G20 that need to be machined according to compression ratio, Nissan piston rings #12033-86G00, Nissan comp head gasket #11044-91MM1, Head is an E-88 with enlarged seats and valves with port work, custom grind cam, TWM intake with tripple Webers. My understanding of this motor is to find the best machine shop possible, hopfully one that has done work on a 3100cc before. The ballance job is critical.

My parts went to the machine shop 3 days ago.

 

i have a reputable engine shop that i have used in the past that everyone around here raves about.. Not sure if they have worked on 3.1L before.. i plan to ask around here before i get to that point to see if anyone knows of a good shop on long island.. Is there a difference between the 240sx pistons and the truck pistons?

 

last question is about the intake.. how do the tripple carbs rate agains fuel injection? I always though the tripple carb high reving 3.1L would be great.. but wasn't sure if injection would be a better setup.

 

 

thanks,

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As I stated before I am no expert. I used a large highly recomended speed/race shop in Reno NV about 15 yr. ago and everything that could go wrong with that engine did. They were not Z experts. They were American V-8 experts. I have spent years reasearching what I wanted in a Z and in findeing a builder that has a passion for the Z car. Such a passion that Mr. K himself would occaissional have dinner with him and more reciently Bob Sharp has called attempting to buy classic race parts. The will to want to build a Z motor without short cuts is what is needed.

 

I have been buying parts for a couple years now and do not rember the exact difference in pistons. Although I think the amount above the top ring is greater on the truck piston. Thus allowing more room to machine the piston to adjust compression ratio.

I have chosen to use Webers as I want a classic preformance restoration and to be naturally asperated. I bought the Webers 15 yr. ago and love them. There is nothing like the sound a set of tripples makes. There are some Utube examples of the sound. Type in (3100 Stroker) and a red Z does some excelleration tests. However there are better preformance options, such as injection. I am not intrested in that type of set up so I cant lend any advise.

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yea i could see that being a problem... i have heard a few with the triplets and they do sound great.. BUT.. as of now.. after reading all i have.. and after what people have been saying to me about the cost and time involved in building a 3.1L and finding the reputable shop.. i think i may change my ways for now.. I still love the 72 240Z, but instead of doing the 3.1l, i think i am going to just go L28ET.... and eventually when i have more time and money down the road.. build a second Z w/ the 3.1L.. but for now.. with my budget. i think the car would be better off and more likley to get finished w/ the L28ET.. figure to get a engine/tranny/ecu setup.. have the engine freshened up / strengthened.... exhaust, intercooler.. and a T3/T4..

 

I know its very different then my original choice.. but i don't want to start the car.. and either not finish... or have it sit for a very long time..

 

And with regards to finding a Z enthusiast shop to build and balance the 3.1... i don't think i will be a problem getting a L28 freshened up and strenghtened....

 

 

As I stated before I am no expert. I used a large highly recomended speed/race shop in Reno NV about 15 yr. ago and everything that could go wrong with that engine did. They were not Z experts. They were American V-8 experts. I have spent years reasearching what I wanted in a Z and in findeing a builder that has a passion for the Z car. Such a passion that Mr. K himself would occaissional have dinner with him and more reciently Bob Sharp has called attempting to buy classic race parts. The will to want to build a Z motor without short cuts is what is needed.

 

I have been buying parts for a couple years now and do not rember the exact difference in pistons. Although I think the amount above the top ring is greater on the truck piston. Thus allowing more room to machine the piston to adjust compression ratio.

I have chosen to use Webers as I want a classic preformance restoration and to be naturally asperated. I bought the Webers 15 yr. ago and love them. There is nothing like the sound a set of tripples makes. There are some Utube examples of the sound. Type in (3100 Stroker) and a red Z does some excelleration tests. However there are better preformance options, such as injection. I am not intrested in that type of set up so I cant lend any advise.

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There's a guy in Co. selling one for ridiculously cheap (compared to building one yourself). Had I not been almost done with mine, I would have snatched this up in a heartbeat (assuming everything that the owner claimed was in there was actually in there). It's in the classifieds now under parts for sale. Trust me - it will save you a load of headache and preparation and countless machine shop costs. If the economy wasn't in the tank, I'd sell some stock and buy it myself just to have a spare.

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There's a guy in Co. selling one for ridiculously cheap (compared to building one yourself). Had I not been almost done with mine, I would have snatched this up in a heartbeat (assuming everything that the owner claimed was in there was actually in there). It's in the classifieds now under parts for sale. Trust me - it will save you a load of headache and preparation and countless machine shop costs. If the economy wasn't in the tank, I'd sell some stock and buy it myself just to have a spare.

 

well part of me wanting to get a Z is the fact that i enjoy working on cars...i am looking forward to taking the engine apart and cleaing / freshening up the motor and being able to say that "I built this", not i bought this then droped it in my car..

 

i am just looking forward to spenidng weekends out in my garrage tearing the car apart and the engine and rebuilding / cleaning eveything for both the car and engine..

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