high performance L18?

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510rob
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RE: Re: RE: Re: high performance L18?

Post by 510rob »

I think the largest auxiliary venturi you can put into a 40mm carb is a 32mm diameter piece.

Also, when you say you can get metal head gaskets, are they MLS shim style, or solid copper?
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Rehs
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Re: RE: Re: RE: Re: high performance L18?

Post by Rehs »

510rob wrote:I think the largest auxiliary venturi you can put into a 40mm carb is a 32mm diameter piece.
I know that their completely different, but the DCOM40s we have on the racecar had 34mm in them when we got them.
datzenmike
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Re: RE: Re: high performance L18?

Post by datzenmike »

badgti wrote:[

40dcoe's are not enuf for 9k rpms? currently i am trying to source for the l28e n.a pistons that are supposed to be flat-tops rite?but they're hard to come by .wht kind of compression will i roughly get if i use a thinner headgasket(i can get metal headgaskets) 0.7mm and just shave the head 0.4mm off?
Stock L18 w/flat tops, 45.3cc open head C/R = 9.02
above but overbored 1mm..............................9.17
overbored 2mm..............................................9.3
above with 41cc P-nut head (87mm bore)........10.0
above with .7mm gasket................................10.56
"Nissan 'shit the bed' when they made these, plain and simple." McShagger510 on flattop SUs
banzai510(hainz)
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Post by banzai510(hainz) »

badgti
Contact Baz in Austrailia at Datsport

I think he has flattops piston for a L18/20
or Steward wilkins motorsport in Austrailia
PS You want you motor to go 9K rpm? better have a better ignition system!!!!!!!!
badgti
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Post by badgti »

banzai510(hainz) wrote:badgti
Contact Baz in Austrailia at Datsport

I think he has flattops piston for a L18/20
or Steward wilkins motorsport in Austrailia
PS You want you motor to go 9K rpm? better have a better ignition system!!!!!!!!
i'll try e-mailing them..thanks
recetly i managed to get a a87 head from th wreckers, are these heads better than the other l-series head if i were to use them on my n.a setup?
banzai510(hainz)
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Post by banzai510(hainz) »

Most people want a true SSS head

But a close chamber W53 or Closed chamber A87 is fine Not all A87 are closed.
Enlarge the intake ports to 1.5 inch and you more or less have SSS spec head.
be honest its nothing really special.
Just best to have the head done by someone who has done L series heads. I seen some people matchpoert the head to 1.5 but the casting is getting thin and could crack when slightly overheated or stressed.

also you caN SPEN MONEY ON THE 280Z VALVES BUT NEEDS NEW SEATS ALSO AND THAT INVOLVES ALOT MORE MACHINE WORK AND i SAY NOT REALLY WORTH IT ON MOST MOTORS

sorry for th caps but not rewriting this
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gbean
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Post by gbean »

I have an L18 in my 510 (from 73 610), with about 6k miles on the rebuild, it has been bored .030 over.
I dont think my setup is as potent as it could be. I dont get a lot of low end, but then I am also not sure if it has a stock cam. (Will check reciepts) after about 3500 RPM is when the motor takes off, but with the stock peashooter exhaust, it is limited by back pressure it seems as far as revving very high before losing power.

I will follow this thread to see what you do man...not trying to threadjack...
(Anyone think I should toss my Weber 32/36 DGV for something better?)
banzai510(hainz)
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Post by banzai510(hainz) »

G bean
32/36 is a good daily driver low maint carb.

or a 32/36 with a turbo

if you want to go faster with a Nat Asperated motor ,sidedrafts are to only way to go but you need a cam to enhance the carbs.


let us know the fix on your car,what was wrong
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gbean
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Post by gbean »

see other thread in just a sec.
"Those people who think they know everything are a great annoyance to those of us who do."
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badgti
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Post by badgti »

seriously, are twin 40dcoe's good enough for a worked l18? i was thinking of going for a 288 duration cams...
Also, are the rods from the fj20e similar to the ones on the l18, can they be used on the l18 since fj20e rods are floating pin types...
banzai510(hainz)
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Post by banzai510(hainz) »

yes webers and mikunis can handle a L18/L20 for sure and that cam.
just getting a good pair of them instead of someones junk.

as for the FJ rods Its was in a book somewhere if they work or not.

remember this is a L motor so if you want MORE power maybe start with a newer motor. cause onece you reach a certain point the Price jumps up alot just to get those extra HP
badgti
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Post by badgti »

guys, how similar are the fj20 rods to thel18?
can the rods be fitted on the l16 crank?
datzenmike
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Post by datzenmike »

The L16/18/20B/L24/26/28/Z18/20/22/24 all have the same rod journal diameter. So yes it will 'fit' the L16 crank. BUT you will need a piston with a pin height of 40.8 at the most, to reach the deck height.
"Nissan 'shit the bed' when they made these, plain and simple." McShagger510 on flattop SUs
badgti
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Post by badgti »

how bout vg30de pistons on fj rods with a l16 crank in a l18block
badgti
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Re: high performance L18?

Post by badgti »

wow,
its been a while since i got back to this, well sorry to bring this zombie thread back but i'va had a lot of fun with the 510 and recently during the last track session the engine decided to give way, and took along rod bearings with it, suspected it was a lack of oil pressure coming due to the massive oil cooler i recently fitted so now a rebuild is underway.
specs of the motor i ran:
l18 fully lightened crank and balanced
l16 rods
oversized l18 pistons and shaved them down
lightened flywheel
ported and polished w53 cyl head
weber 45mm dcoe's
msd 6al
do you guys have any recommendation of cams that i could get ? who sells em? i seriously am lacking top end power on circuit , any ideas on this ?
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