# Pathy Burnout Video!!



## 89PathSE (Feb 26, 2004)

Hey guys... got a new video of my '89 Pathy doing a 2nd gear burnout... come see!! www.lpperformance.com Go to the pics/video section. VG30I, all motor, flat top pistons, completely ported, port matched, and polished from the fuel injection all the way to the full length headers, reshaped combustion chambers, 11:1 compression, swirl polished valves, radiused valve seats, 242 cams, adjustable cam gears.


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## morepower2 (Apr 19, 2002)

89PathSE said:


> Hey guys... got a new video of my '89 Pathy doing a 2nd gear burnout... come see!! www.lpperformance.com Go to the pics/video section. VG30I, all motor, flat top pistons, completely ported, port matched, and polished from the fuel injection all the way to the full length headers, reshaped combustion chambers, 11:1 compression, swirl polished valves, radiused valve seats, 242 cams, adjustable cam gears.


Ummm. If you have flat tops then your compression is around 9.6-10:1 unless your head is milled or quench welded or something.

I need to talk to you about your center link assembly.

Mike


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## 89PathSE (Feb 26, 2004)

morepower2 said:


> Ummm. If you have flat tops then your compression is around 9.6-10:1 unless your head is milled or quench welded or something.
> 
> I need to talk to you about your center link assembly.
> 
> Mike


Umm... I am a mechanical engineer, and owner of L&P Performance... they ARE 11:1, engine was 9:1 before... hehe... I decked, yes me, the heads 100 thousandths (0.1"). They have a very large quench area as well... got some pics somewhere I think.  

For the centerlink.... you can email us at any time for anything, or feel free to openly ask here.... email addy is [email protected]

Lee McQuinn
89PathSE
Mechanical Design Engineer, L&P Performance


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## morepower2 (Apr 19, 2002)

89PathSE said:


> Umm... I am a mechanical engineer, and owner of L&P Performance... they ARE 11:1, engine was 9:1 before... hehe... I decked, yes me, the heads 100 thousandths (0.1"). They have a very large quench area as well... got some pics somewhere I think.
> 
> For the centerlink.... you can email us at any time for anything, or feel free to openly ask here.... email addy is [email protected]
> 
> ...


The stock VG is 8.8:1, Wow .100" how did you correct your cam timing, especialy on the right bank of the motor? Do you make adjustable timing gears for the VG?

How does you motor run on pump gas? Any detonation problems? What cams are you running?

Mike


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## 89PathSE (Feb 26, 2004)

morepower2 said:


> The stock VG is 8.8:1, Wow .100" how did you correct your cam timing, especialy on the right bank of the motor? Do you make adjustable timing gears for the VG?
> 
> How does you motor run on pump gas? Any detonation problems? What cams are you running?
> 
> Mike


No it wasn't... I cc'ed the heads, and the pistons are perfectly flush with the block deck at TDC... combustion chambers measured right at 62cc.... 87mm bore, 83mm stroke.... thats almost exactly 9:1. I run the stock cams, 242 degrees I believe. We make adjustable cam sprockets... its one of the things we offer at L&P Performance. No detonation.... 93 octane.... 12 degrees BTDC (best as I can tell anyhow). The other thing is... the quench area of the head was made vastly larger due to being decked... helps with detonation a lot.... also, combustion chambers were polished to a near mirror finish.... also helps.... plus.... my O2 sensor and lack of any emissions crap make the engine run a lil extra rich. The intake manifold had to be machined too.... cuz of the heads being decked so drasticly. I am gona buy some NISMO race cams in the very near future and put them in over an evening some night.... but for now it loves the 242 cams with about 5 degrees backed off with the adjustable sprockets.


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## morepower2 (Apr 19, 2002)

89PathSE said:


> No it wasn't... I cc'ed the heads, and the pistons are perfectly flush with the block deck at TDC... combustion chambers measured right at 62cc.... 87mm bore, 83mm stroke.... thats almost exactly 9:1. I run the stock cams, 242 degrees I believe. We make adjustable cam sprockets... its one of the things we offer at L&P Performance. No detonation.... 93 octane.... 12 degrees BTDC (best as I can tell anyhow). The other thing is... the quench area of the head was made vastly larger due to being decked... helps with detonation a lot.... also, combustion chambers were polished to a near mirror finish.... also helps.... plus.... my O2 sensor and lack of any emissions crap make the engine run a lil extra rich. The intake manifold had to be machined too.... cuz of the heads being decked so drasticly. I am gona buy some NISMO race cams in the very near future and put them in over an evening some night.... but for now it loves the 242 cams with about 5 degrees backed off with the adjustable sprockets.


The pistons are about .007 below deck on the stock motor and did you conside the compressed gasket volume? I am wondering because I come up with a lower number after doing the same thing.

Actualy the Pathfinder runs way too rich stock even when things are right, like in the 11:1 range in the high load parts of the map. Getting a JWT ecu leans this out to the still conservative low 12's and gets you more power. Cams make a huge difference. I recomend the Nissan Motorsports 262 cams for towing and off road or the JWT stage 2 cams for best overall power. Nismo does not make VG30E cams.

Did you dyno your engine yet/

Mike


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## 89PathSE (Feb 26, 2004)

morepower2 said:


> The pistons are about .007 below deck on the stock motor and did you conside the compressed gasket volume? I am wondering because I come up with a lower number after doing the same thing.
> 
> Actualy the Pathfinder runs way too rich stock even when things are right, like in the 11:1 range in the high load parts of the map. Getting a JWT ecu leans this out to the still conservative low 12's and gets you more power. Cams make a huge difference. I recomend the Nissan Motorsports 262 cams for towing and off road or the JWT stage 2 cams for best overall power. Nismo does not make VG30E cams.
> 
> ...


Yeah, your right... if you pull a piston to TDC... you can fit about a 5 thousandths feeler guage in there between a straight edge... but it is miniscule. Yes, I compensated for the head gasket... try your math again.... everything included, its ~62cc's (actual measured chamber volume, including a tollerance of .005" for deck height above piston as well as the head gasket's 2/50" thickness comes out to 61.5 cc's of total combustion chamber volume +/- .5cc due to the innacuracy of the OEM castings) for each chamber on the OEM casting. 

Your also right about the mixture.... as I said, it runs a bit rich.... its due to the type of O2 sensor Nissan used.... its either on or off, depending on mixture condition, no in between.... it just happens to activate at arround 11.3 a/f.... so your right on there. 

Its not a VG30E... its a VG30I... obviously only different in the fuel injection system. I am not going to buy a JWT ECU for several reasons... Firstly is price. Secondly... fuel ratio can be easily modded on the VG30I's throttle body injection system... I spent 2 weeks studying every little internal detail of one... its all in manipulation of the mass air sensor.... it does not measure air flow directly, but rather measures a percentage using a series of passageways in the TBI unit which opperate on a sort of venturi effect.... its rather complicated so I am not going into it further than that. The ignition mapping I will do myself on a dyno with an MSD DIS ignition box that I planned on buying anyways. 

NISMO did (I think) offer a cam for the VG30 SOHC motors.... its a 264/262 .392" cam... atleast thats what's claimed, I could be wrong though.... got any info on it? I also been looking at the ISKY cams... and yes, the motorsport ones I had my eye on too. I mapped a bunch of cams on my dyno software.... the motorsport 270 cams do the best in my RPM range.... I smack revlimiter at an unfortunate 6200 rpm (which is the only reason I would get a JWT ecu). I do a lot of offroading, not much towing.... I dont really care about loosing low end. I want max horepower, which as you can see... it runs quite well come rollin' arround 4900 rpm.

I have not had time to dyno the truck yet.... near future. Dyno software (as closely as I can replicate the probable flow of the heads) says arround 230 Bhp @ 235 ft. lbs. closer to 5300 rpm with my current cam setup.


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## Ruben (Oct 15, 2002)

Its official, I am now dizzy.  Nice work.


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## morepower2 (Apr 19, 2002)

89PathSE said:


> Yeah, your right... if you pull a piston to TDC... you can fit about a 5 thousandths feeler guage in there between a straight edge... but it is miniscule. Yes, I compensated for the head gasket... try your math again.... everything included, its ~62cc's (actual measured chamber volume, including a tollerance of .005" for deck height above piston as well as the head gasket's 2/50" thickness comes out to 61.5 cc's of total combustion chamber volume +/- .5cc due to the innacuracy of the OEM castings) for each chamber on the OEM casting.
> 
> Your also right about the mixture.... as I said, it runs a bit rich.... its due to the type of O2 sensor Nissan used.... its either on or off, depending on mixture condition, no in between.... it just happens to activate at arround 11.3 a/f.... so your right on there.
> 
> ...


AH ok you have a TBI engine. I don't know too much about how those work, never messed with one. Nismo does not make VG30 cams. Nissan motorsports makes a 256 and 262 duration cam with about .390 lift. The Motorsports cams make the best low end torque but the JWT cams make the best power above 4500 rpm. The Stage 2 cam makes the most power of all the VG30 cams. If you don't care about bottom end, I recomend that cam. Its good for about 12 hp over the Nissan Motorsports 262. The isky cams are very simular to the Nissan Motorsports. You wont belive how cams will wake up your engine.

I would probably convert to TPI as well, you'll get a bunch of hp and torque as well. The Pathfinder TPI manfold is the best of the VG30 manifolds, the Z guys are all swtiching over to it. Your software is about right when it comes to power estimation.

Mike


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## 89PathSE (Feb 26, 2004)

morepower2 said:


> AH ok you have a TBI engine. I don't know too much about how those work, never messed with one. Nismo does not make VG30 cams. Nissan motorsports makes a 256 and 262 duration cam with about .390 lift. The Motorsports cams make the best low end torque but the JWT cams make the best power above 4500 rpm. The Stage 2 cam makes the most power of all the VG30 cams. If you don't care about bottom end, I recomend that cam. Its good for about 12 hp over the Nissan Motorsports 262. The isky cams are very simular to the Nissan Motorsports. You wont belive how cams will wake up your engine.
> 
> I would probably convert to TPI as well, you'll get a bunch of hp and torque as well. The Pathfinder TPI manfold is the best of the VG30 manifolds, the Z guys are all swtiching over to it. Your software is about right when it comes to power estimation.
> 
> Mike


Actually... I am working on a completely new manifold.... Its all hand fabricated from T6 aluminum.... it will run a 3-pack of TBI units, yes, I said THREE SEPERATE TBI UNITS! (almost 900 cfm of flow). The manifold is much better than any OEM unit, ported or not... its a tunnel-ram style manifold with a large upper plenum.... all runners are individualy velocity-stacked into the upper plenum, as is each TBI unit. In the end... I'll have enough injector flow and cfm to support over 600 horses (for later use with my M90 Eaton Supercharger and air-water intercooler).


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## morepower2 (Apr 19, 2002)

89PathSE said:


> Actually... I am working on a completely new manifold.... Its all hand fabricated from T6 aluminum.... it will run a 3-pack of TBI units, yes, I said THREE SEPERATE TBI UNITS! (almost 900 cfm of flow). The manifold is much better than any OEM unit, ported or not... its a tunnel-ram style manifold with a large upper plenum.... all runners are individualy velocity-stacked into the upper plenum, as is each TBI unit. In the end... I'll have enough injector flow and cfm to support over 600 horses (for later use with my M90 Eaton Supercharger and air-water intercooler).


How about a big box plenum manifold with stacks inside that bolts to the stock base using a Q45 thottle body? That would be easier and cheaper to make and proably work better.

Mike


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## 89PathSE (Feb 26, 2004)

Actually what I am making is by far the best approach.... equal length runners, seperate water passages so as not to heat the rest of the manifold with hot coolant flow, it HAS a large box plenum up top.... mounts all three TBI units on top. Each runner is welded up to the plenum with its own small velocity stack. Each TBI unit bolts to the top side of the plenum with ITS own lil' velocity stack. Each runner is about 4 inches long and points straight into the intake ports on the heads. its quite a work of art if I do say so myself. hehehe


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## morepower2 (Apr 19, 2002)

89PathSE said:


> Actually what I am making is by far the best approach.... equal length runners, seperate water passages so as not to heat the rest of the manifold with hot coolant flow, it HAS a large box plenum up top.... mounts all three TBI units on top. Each runner is welded up to the plenum with its own small velocity stack. Each TBI unit bolts to the top side of the plenum with ITS own lil' velocity stack. Each runner is about 4 inches long and points straight into the intake ports on the heads. its quite a work of art if I do say so myself. hehehe


Post pic's when done!

Mike


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## 89PathSE (Feb 26, 2004)

morepower2 said:


> Post pic's when done!
> 
> Mike


Will do... I already have the base manifold put together (flanges, bolt holes, coolant system).... and most of the rest is already cut and fit... just gotta find the time to sit down with the ol' MIG and get welding.


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## morepower2 (Apr 19, 2002)

89PathSE said:


> Will do... I already have the base manifold put together (flanges, bolt holes, coolant system).... and most of the rest is already cut and fit... just gotta find the time to sit down with the ol' MIG and get welding.


Eagerly awaiting shots and dyno results, heck if it works good, can you make me one, except with a single TB for my TPI setup?

Mike


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## 89PathSE (Feb 26, 2004)

morepower2 said:


> Eagerly awaiting shots and dyno results, heck if it works good, can you make me one, except with a single TB for my TPI setup?
> 
> Mike


Sure!... though for you, might consider just making a new upper plenum to bolt on to the lower plenum (which I'd port and match for you). That way I dont have to screw with making injector ports on all the runners. Your lower manifold aint too bad, its the upper that sucks. I'd make you a large volume upper plenum, short runner length, front mounted single TB of your choise (we can make the TPS sensor work with it too).


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## morepower2 (Apr 19, 2002)

89PathSE said:


> Sure!... though for you, might consider just making a new upper plenum to bolt on to the lower plenum (which I'd port and match for you). That way I dont have to screw with making injector ports on all the runners. Your lower manifold aint too bad, its the upper that sucks. I'd make you a large volume upper plenum, short runner length, front mounted single TB of your choise (we can make the TPS sensor work with it too).


Thats what I had in mind, I wonder if it would loose much torque?

Mike


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## 89PathSE (Feb 26, 2004)

morepower2 said:


> Thats what I had in mind, I wonder if it would loose much torque?
> 
> Mike


It'd probably only help, if anything.... I can make you long runners, thats no problem. I'd just have to go to the muffler shop and have them mandrel bend up 6 aluminum tubes to my specifications.... ie, it'd point straight up, then a sharp right, then to the plenum box..... OR... you could do what I have to do, and fiberglass a cowl hood scoop to a hole in your hood to cover the intake.... that way it can stick straight up for better laminar flow.


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