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Maximum L24 bore


z-spec

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I have an L26 block (83 mms) bored out 100 thou (2.5mm's). I didn't do it but received the block from a friend with it already done.

 

I think that its important to realize that there is a limit to the amount of overbore that still renders the whole thing as reliable. If you're going to build a race engine, cylinder temps and pressures are much higher than stock as well as the redline. The chance of splitting the block as a result are greater and you'll be searching for another block or sleeving that one in a hurry.

 

One or one and a half mm's will give you a capacity increase without the potential headaches associated with extreme overbores.

 

You can if you wanted too add heaps of capacity via a diesel crank to the engine if you must have an L24 block. Fantastic mid range punch would be the benefit of that combination, compared to the standard L24. Even the L26/28 crank will make a bigger engine than the one you already have. So many options!!! Good luck with your project.

 

Cheers.

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Ok, so you wanna race.

 

P30 block has a max factory reccommended overbore of 2mm. SO, here's a combo with L20B pistons, L24 crank, L24 rods and an N42 cylinder head.

 

2.5L with a 7.4:1 compression ratio, boost ready.

 

OR

 

P30 block, Z20S pistons, L28 crank, L24 rods, MN47 cylinder head

 

2.6L 11.1:1 compression ratio, ready for 93 octane or better. Run triples and a BIG CAM for best results :)

 

OR

 

P30 block, LD28 crank, L28 rods, Z20S pistons, P90 cylinder head

 

2.8L 8.4:1 compression, boost at will.

 

Or, same as above with E88 head:

 

2.8L with 9.7:1 compression, run megasquirt and a MONSTOR cam

 

That's my quick answer, your mileage and results will vary.

 

Check out Ozdat's engine calculator, that's where all this came from.

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On my track car i had a L24 block with a modified E88 head and standard bore and stroke , and 45 weber carbs, it use to have 220Hp mesured on the crank .

I swop the crank with a L28 , and compensate the compresion to 10.5-1

like it was .

but I wondering or sombody has expiriece with bore a L24 block or even sleeve a L24 block to a bigger bore ?

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Ad,

In Japan they would use Diesel Wet Liners and sleeve the block on the 1998 cc L20A six cylinder to be able to accomodate L24 internals.

 

I don't see any reason the architecture on the L24 block would preclude that to give you at least 2.8 capacity with an L28 crank, or even more with the LD crank in there.

 

The L28 crank in the L24 bore simply gives you an L26 with std/std components. Bored gets you closer to L28 capacity, and with the aftermarket sleeves, you may be able to make a stroked capacity 3.0 Liter assembly. When in doubt, sleeve! LOL

 

I will likely take this route on the 260Z since it's numbers-matching.

 

How comes the project from the Pig Barn?

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The pig is still sticking his nose in the mud ,

How was your bullfighting adventure in Spain ?

 

My idee is to bore a L24 to max bore even if i go trough the water pockets and put ± 3mm thick sleeves into it , this is what we also do with Turbo Cosworth engine , but what worries me is the strenght and rigidety of the block ,

Tony have ever see a gurdle on the main caps os a L serie like they do with ford and chev v8 .

 

Regards Ad ( Spa 6 Hours is becoming verry close and we have plenty of food and beer )

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My idee is to bore a L24 to max bore even if i go trough the water pockets and put ± 3mm thick sleeves into it , this is what we also do with Turbo Cosworth engine , but what worries me is the strenght and rigidety of the block ,

Tony have ever see a gurdle on the main caps os a L serie like they do with ford and chev v8 .

 

 

Don't you love the way that we're given 'extra' information after half a dozen posts or so!!?

 

Why don't you give everyone a chance to answer your questions properly with everything that you know your going to do to the engine at the beginning!!!!

 

And how much power do you expect to be making? If you had looked around on this forum first, you would see that many people are making more than 400rwhp. I think the L series block is pretty tough...tough enough to be making this sort of power.

 

Sorry if I sound 'narky' but its this type of open ended question with dribbles of information supplied by you that gets under my skin.....get to the point :sour:

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Don't you love the way that we're given 'extra' information after half a dozen posts or so!!?

 

Why don't you give everyone a chance to answer your questions properly with everything that you know your going to do to the engine at the beginning!!!!

 

And how much power do you expect to be making? If you had looked around on this forum first, you would see that many people are making more than 400rwhp. I think the L series block is pretty tough...tough enough to be making this sort of power.

 

Sorry if I sound 'narky' but its this type of open ended question with dribbles of information supplied by you that gets under my skin.....get to the point :sour:

 

We gone race these cars in Europe and we do not need 400Bhp , we stick to FIA regulation with classic racing , classes uptil 1965 , classes uptil 1972 , and for us it searching to get as much benefit out of a L24 block , for sure it is easyer to take a L28 block .

But everybody with a little knowledge about L serie engines can see the differents between a L24 and a L28 by miles away .

We are professional in the busines and had already a lot of succes in classic endurance racing in Europe with v8 cars .

We look to your period cars to challange the porsches in Europe and we are already compete with one 240Z in rallys, circuit racing wil be the next move but not a lot of people understand about FIA regulation , as long you respect these you can drive in beautyfull event like Nurburgring Marathon , Spa 6 Hours and even Le Mans Classic

I do not ask stupid questions i just ask for people with some expiriece with were i ask for . www.va-motorsport.com

Regards Adrian,

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There indeed is a stud girdle available for the L-Series. Japanese, of course.

part_004.jpg

There was debate about it, of course, but the component does exist out of Japan.

http://www.grit-tune.com/part.html (About 3/4 way down the page)

 

This is the thread: http://forums.hybridz.org/showthread.php?t=123513

 

The discussion was about a 'block brace' which the Hondas use. The product exists for some reason, may be a competitive environment is a bit different than short bursts or someting in a club racing environment? Sniping at a man who competitively races GT350 Shelby Mustangs at LeMans (and if you've visited his linked site should reveal a slight bit more knowledge than most here regarding high-end competition in motorsports) should be poor form even in the land of Oz...especially given he's posting in a second language (of several he speaks). Perhaps dribbling is a better way to work up to it---Do you have a comprehensive solution to his query OZ, or are you just standing on form and principle as protector of ettiquette? I'd worry less about form and more on solutions, personally. Just my opinion.

 

I mean, you did see his second post where he refined the question to encompass sleeving right? That's a big clue that 'maximum bore' means 'maximum bore'---the only limitation would be sleeve major diameter impinging on block head stud integrity and desired sleeve wall thickness. If you consdier an 86mm bore of the sleeve, +3mm walls that would give you only 92mm...and there are engines (L28's out there) that are bored to 90.5mm and running on the block's metal, so the real question is when using sleeves, would the extra 0.040" cut to go from 90.5 to 92.5mm impinge upon the stud integrity...there is a possibility that with an L28 block you would still have a dry sleeve situation with a 92mm major diameter sleeve! Meaning, the L24 Architecture would support that as stud spacing did not change between L24/L28 Bores. The real question, as Bryan pointed out, is 'what is the core thickness around the L24 Bore'? That will determine if the sleeve at a 92mm major diameter (and an 86mm Piston Bore) will be wet, or dry. It's been done in Japan on smaller cars to defraud the inspectors to keep a vehicle in the 2 Liter Tax Class while running an L24 internals set. The art died out in practice by the late 80's due to Shaken allowing motor swaps, and the advantages of the larger displacement of the L28 out of the box without any expensive machine work. But if you are required to run an L24 Block for class requirements....

 

Ad, I think the sleeve will work cut as you propose---I believe the bore on the L20A's was cut in similar manner to be able to use the L24 Pistons in the Diesel Liners. The block is really rigid. And the earlier blocks are tougher than most of the very last production models of the L28 anyway---metalurgy changed for cost reductions once they altered the cooling jackets. A stud girdle wouldn't hurt when doing it. Nothing like finding a broken crank to ruin a day at the track!

 

I'm going to have to check with what is on the schedule, the people in Madrid jsut sent an (untranslated) e-mail and from what I can gather, they want hands-on technical assistance again. So I may be 'in the area' sooner than I anticipated. Then it's just a matter of making my wife upset as I 'take vacation' in conjunction with another overseas job! LOL

 

She will be upset, because she finally got her passport re-issued! He he he he he!

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Tony , 6 Hour Spa is 27 sept. , We enter two Shelbys one from the Belgian equipe who crashed heavely last year in practice and the second car I share with the two South Africans , your welkom

I also gone bring the red 240Z to Spa , but we do not race it ( yet )

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Tony, I really look forward to reading your posts on hybridz. You obviously know a great deal about all things automotive and Nissan/Datsun specifically and its this knowledge that I appreciate from you.

 

I cannot provide z-spec with all the answers that he's seeking. I simply do not have that sort of experience. As much as I would like to own several race cars and race them around the world, I am but mere mortal so it remains a pipe dream only. I do enjoy reading and have gathered quite a library of automotive literature that allows me to further investigate some of the thoughts and ideas that people bring up. So when a question is posted, it should be fairly obvious that as much relevant information be provided to allow for a timely, accurate response by the readers and responders. I do not have the time nor interest to be reading what other people did for breakfast last week or even for next week. That's all. Country of origin is irrelevant. Number of languages spoken well that's also irrelevant. Why should that make any difference to anyone?

 

I stand by what I said earlier to Z-car, get to the point.

 

Thanks.

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Country of origin is irrelevant. Number of languages spoken well that's also irrelevant. Why should that make any difference to anyone?

 

I stand by what I said earlier to Z-car, get to the point.

 

Thanks.

 

The relevance in this is fairly easy.... someone that is not a native speaker will have more 'problems'

 

A: translating technical terms

B: maybe has different rules of engagement in a conversation.

You as an Ozzie should know that for instance PC'ness is much more an issue in Japan or the US for that matter than it is 'downunder'

 

You could also see that as translating all the words might lead to a shorter post. leaving just the bare essentials, though i agree more info will lead to better answers .

Anyway the question was fairly thoroughly answered in the post above

 

 

I like those gurdles :)

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Frank I think has addressed the 'relevance'---syntax, speech patterns, and not being a 'native speaker' all contribute to a question that may not meet a 'native speakers' definition of 'full disclosure'.

Your definition of 'all the relevant information' may be considerably different than someone from another country, culture, or even social background.

 

My point was that the important thing is wether the relevant information does get conveyed. Jumping on someone and making cracks about their presentation is poor form IMO, and smacks of ridicule just because someone is not a native speaker.

 

Could you converse in written German and phrase a sentence as completely? Dutch? Malay? Farsi? If not, then consider what it must be like for someone who comes from any of those countries to ask questions in English...written English at that. Not everyone speaks English around the world, and though this board is predicated on a basic English Knowledge---I don't think you are suggesting that people who arent fully conversant in English Bugger Off and not bother us here...but in effect that is what (from what I saw) your post above as doing.

 

Focus on the questions, and the solutions, and far less on the form of the delivery. You seem upset that it took a 'half dozen posts or so' to get what his aims are. Perhaps that's because it took someone actually answering his question to have him refine his aims. You really missed an opportunity to note for him that the L26 Bore is the same as the L24 Bore, but then again the casting for an L26 may be different than an L24 so is it really pertinent information that you provided in the reply to him initially? Your post was probably more relevant to my statement later on overboring my 260Z for L28 Internals to keep it numbers-matching. An L26 shares the same bores, but is it an L24? Do we know that?

He asked about sleeving as an alternative---you hadn't answered that regard. I did, and he further replied what his logic was for asking the question in the first place...after he was informed that indeed people have bored to water jacket and sleeved these engines successfully in the past.

 

I just see it as a bit over the top to get so upset that you post something like you did without any consideration that it's not a native speaker of English posting the query. Maybe its because I do this all the time in my job that I understand the difficulties of conveying highly technical information to people of different languages and clutures, and so have more tolerance than someone who never has had to do that.

 

Would it have been better if he posted the full question in Dutch? German? Would anybody here have been able to give any help?

 

For someone bending over backwards to accomodate our demand that he converse in a language that is easy for us to understand...I think the least we can do is be a bit more understanding that maybe we will have to bear with them as they fight for the words to use to convey what they clearly know in their own language, and translate it into ours for us.

 

As a native English Speaker, I am grateful to find someone at a plantsite that can speak English to assist in my job overseas. I think we should be a bit more grateful that the effort has been made, rather than critical that the effort was not perfect out the gate.

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DeNada, Amigo!

I'm not trying to P.O. anybody, having 'been in his shoes' I kinda have sympathy for the monumental task of communicating what exactly I want to convey to people who don't speak 'my' language. And my attempts at other languages...let's not even go there! "Ice" "Thanks" & "Massage" I have down...after that it gets really sketchy!

 

In the field, technical stuff can some times take (I am not exaggerating) weeks...

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DeNada, Amigo!

I'm not trying to P.O. anybody, having 'been in his shoes' I kinda have sympathy for the monumental task of communicating what exactly I want to convey to people who don't speak 'my' language. And my attempts at other languages...let's not even go there! "Ice" "Thanks" & "Massage" I have down...after that it gets really sketchy!

 

In the field, technical stuff can some times take (I am not exaggerating) weeks...

 

One thing that I can tell your experience has brought about in you, Tony, is a particular regard for the nuances and specific meanings to words in English, as used by english speakers! When speaking in a highly technical forum, nuances and "semantics" are HIGHLY relevant, and it is growing difficult to find native speakers of English with an adequate command over their own thoughts and their own (our own) language to assign the proper words to given thoughts, and the proper thoughts to given words.

 

This issue is the very core of the concept of "shallow" or "superficial." English is a very subtle language, when it comes to precision of intended thought. Why else would the USA be run by a galloping gaggle of lawyers? Without thorough and rigid definition of vocabulary terms, using the language makes it very easy to get mentally lazy and that is the beginning of a VERY slippery slope that ends in senility and adult incontinence products. (Thanks, Oops I Crapped My Pants!)

 

I have no point to make on-topic, or even to OZ.. I simply never fail to applaud the Forces of Semanticism And Specific Definition.

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You want a nuanced language, try negotiating with Japanese, or Chinese.

 

Understaning what they are semantically saying is one thing.

Understanding what they are meaning, culturally and functionally...is something totally different.

 

"Yes" doesn't mean "Yes", they just said it because it's what you wanted to hear. Getting upset with them when the deadline is not met doesn't do anything except reinforce within them their preconceived notion that you aren't in control of 'rational understanding of how things have always been done'!

 

"We Digress..." LOL

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