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Building Another Stroker Engine for the Track


inline6

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"I'd like to use my Sunbelt cam which revs to 7700 and that really isn't what the 3.3L is about."

 

Only in America.

 

There is a 3.4 being built right now with full intentions of seeing 8,500.

 

On the street.

 

Hmmm.  For the street?  Will it be "soggy below 6(k)" per another one of your recent posts?  I think you were specifically speaking of use in an L24, but how much different would this 8500 rpm cam be in a 3.4L?  Different enough to be good for "on the street"?  

 

Just trying to understand because I'd really, really, like to use my Sunbelt cam in the 89 mm X 89 mm version with Honda rods for the bottom end (3.3 L). Toward that goal, I recently sourced a factory nos P90A with the bigger combustion chambers...

Edited by inline6
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Any L20A will be soggy with 45mm ITB's, and an rpm potential (demonstrated no-valve float of 12,500+)... The L28 was much more torquey, but we didn't have 5-series gears. I addressed the inability of some to properly select gearing and tire heights for the track they're running.

 

You're convinced and I'm not changing your mind so I'm not even engaging in trying to bust your paradigm.

 

You just grew up on the wrong side of the pond, and you know what you know.

 

The L28 has no practical limitation, and the issues  about 'dwelling' in the region on-track were already adequately addressed by John Coffey in his comments.

 

I continued to take your troll baiting. I'm at an end. Build what you want and I'll snicker when that one blows up, as well.

 

There's nothing like watching someone who knows it all convince themselves of something and then fullfilling their own prophecy.

 

Andy and I once had a guy with a V8 Z lecture us about how the deck was stacked at the SCTA towards Roadsters and how a car like the Z would never become points champion due to the politics involved, and the 'inherent inability of the Z-Car Aerodynamics to exceed 155 mph". We took points champion that year, and in fact were first in points at that point and had just made a 163mph+ pass that day when the guy approached us...

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You're convinced and I'm not changing your mind so I'm not even engaging in trying to bust your paradigm.

 

You just grew up on the wrong side of the pond, and you know what you know.

 

The L28 has no practical limitation, and the issues  about 'dwelling' in the region on-track were already adequately addressed by John Coffey in his comments.

 

I continued to take your troll baiting. I'm at an end. Build what you want and I'll snicker when that one blows up, as well.

 

There's nothing like watching someone who knows it all convince themselves of something and then fullfilling their own prophecy.

 

You are wrong to relegate me to one of those who has grasped onto a paradigm that the L6 can't rev safely beyond X.  I am well aware of your L20 powered car (have commented in the past on such) and others who have revved various displacements of the L6 well beyond the "7200", "7500", "8000", etc. so called "limits".

 

I don't have enough time outside of work, or a staff of minions to do my bidding, or the desire to spend the potentially couple of tens of thousands of dollars (on engines and test equip, further ed., etc.) it would take for me to learn first hand what others (who, to my knowledge, are not competitors BTW) already know.  If I did have those things, I would do/utilize them.  To be clear, it is not an inability to get off my ass, nor is it that I am lacking in brain capacity.

 

Instead, given the constraints I do have, I believe it is wise to seek the commentary/advice of those in this community who are more knowledgeable.

 

This piece of what you had to say was valuable:

 

The L28 has no practical limitation, and the issues  about 'dwelling' in the region on-track were already adequately addressed by John Coffey in his comments.

 

John's comment was read, processed, and stored when he provided it - it was very helpful, specifically because it was a solution backed up via real world experience to an important issue I wanted to learn more about.  
 

I'll add to my knowledge in this subject matter area as I can.  I'll apply it in the most judicious way I can for my particular application and hope it will lead to good results and good fortune.  Along the way, I believe some others will get value from my efforts to share here also.

 

You snicker at other's... because they have inaccurate information, because they have less knowledge in a given subject area, because you have a preference to be acerbic along with your teaching, or because of their misfortune, as you wish.

 

Garrett

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I was just looking at some of your pictures and was quite surprised that for a race engine, the crank had not been dowelled. With the on and off the throttle at high revs there can be some movement of the flywheel under the bolts. As the bolt threads cut into the flywheel the movement will increase. Just a thought.

David.

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Seeing dowels installed in the cranks in the "How to Modify Your Nissan/Datsun OHC Engine" book by Honsowetz years ago, I thought their only purpose was to aid more strength to keep the flywheel from sheering off.  Now I see what else can happen if you don't have them, so I'll be sure to add them to the next build.

Edited by inline6
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Yes, I have been emailing Les quite a bit as of late.  He shared that video with me and I've watched all of the others that his CA customer has put up thus far.  Pretty awesome.  

 

I've been considering building the 3.3L with Les' kit, but I'd like to use my Sunbelt cam which revs to 7700 and that really isn't what the 3.3L is about.  

 

Given the amount of R&D that went into the original engine as a complete package why would you want to mess with it and use a different cam? Seriously I don't understand the reasoning.

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Given the amount of R&D that went into the original engine as a complete package why would you want to mess with it and use a different cam? Seriously I don't understand the reasoning.

 

There is a lot to be said for this... a very well designed package that is backed with success in the real world. That said, here is my reasoning:

 

My personal preference... I like the sound of our venerable L6 when it is revving at 7700 more than when it is revving at 7000.

 

I have the Sunbelt cam, springs and retainers in my possession... which is to say I have a sunk cost of upwards of $1500 USD in camshaft related hardware (cam, springs, retainers, rockers) that if sold would be lucky to fetch 1/2 of that.

 

I like the engine characteristics with the Sunbelt cam.  It was streetable enough... had a lope at idle, and revved easily at the high end, all of which, I like.  Though with the 3.3 L displacement vs. the 2.9 L I had before, my understanding is that those characteristics would be altered a bit.

 

With my current transmission, differential, and rear tire size, the 7700 RPM works well to keep engine operating range in the torque/power making rpm zones for all gears I would use at the track:

 

post-4218-0-36831600-1445038915_thumb.jpg

 

Though again, this transmission will have to be a short term solution as the torque output is too high for it over the long term.

 

However, I have been given a lot of info outside of the forums that I am still processing.  

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There is a lot to be said for this... a very well designed package that is backed with success in the real world. That said, here is my reasoning:

 

My personal preference... I like the sound of our venerable L6 when it is revving at 7700 more than when it is revving at 7000.

 

I have the Sunbelt cam, springs and retainers in my possession... which is to say I have a sunk cost of upwards of $1500 USD in camshaft related hardware (cam, springs, retainers, rockers) that if sold would be lucky to fetch 1/2 of that.

 

I like the engine characteristics with the Sunbelt cam.  It was streetable enough... had a lope at idle, and revved easily at the high end, all of which, I like.  Though with the 3.3 L displacement vs. the 2.9 L I had before, my understanding is that those characteristics would be altered a bit.

 

With my current transmission, differential, and rear tire size, the 7700 RPM works well to keep engine operating range in the torque/power making rpm zones for all gears I would use at the track:

 

attachicon.gifTransmission Ratios.JPG

 

Though again, this transmission will have to be a short term solution as the torque output is too high for it over the long term.

 

However, I have been given a lot of info outside of the forums that I am still processing.  

MJ.gif

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  • 3 weeks later...

One of my two N42 blocks has been disassembled and sonic checked.  Here are the results.  "x"s mark exhaust valve location.  The "T" measurements are top of the bore and "B" are bottom.

 

post-4218-0-17530900-1446912646_thumb.jpg

 

The thinnest measurement was on cylinder 4 where coolant flows between cylinders 3 and 4.  The measurement there was .220".  There is also a spot on cylinder 2 that was .230".  We're looking to bore out the block to 89 mm.  To do so, we have to take .059" out of the cylinder wall all the way around.  So, at the thinnest point, we could be at .220" - .059" = .161".  And at the .230", we'd be at .171".

 

My engine builder recommends going no lower than .180".  My recollection of the guidance from several here on hybridz is for normal aspiration (NA) going no more than .125".  I have read that some have had to check 4 or 5 blocks before finding one that will take an overbore to 89 mm.  If the .125" guidance is acceptable, and our measurements are correct, it seems this block would be good for 90 mm.  It seems that I have gotten lucky with the first of the two blocks.

 

If we offset bore cylinder 4 directly toward cylinder 5, we should be able to end up with .170" (.010" offset) or ,180" (.020" offset), but perhaps that is not necessary?

Edited by inline6
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  • 3 years later...
  • 4 years later...

Nearly 8 years later, I have a replacement engine, which I received today.  Not much to see, but here are some pics:

IMG_20230731_175341.jpg.9c4a4c7b73bc6a1f16c636bf354946c5.jpg  IMG_20230731_175353.jpg.f6439de822cf85a73fff77b09b88e1b4.jpg

 

IMG_20230731_175413.jpg.24557e9fa5bbfbc699e22a3029b447ea.jpg  IMG_20230731_175428.jpg.72fea8e10e9e1823833ff0268f35e01c.jpg

I have a lot of work to do before it can be fired up in the car.  So, it will be a while before that happens.  

This motor is very similar to the one I destroyed.  Changes are 89 mm bore, (now a 3.0 liter vs. 2.9 before), Intake valves are titanium (vs. stainless before), crankshaft this time is not lightened and knife-edged, and this engine will utilize a dry sump oiling system.  

I have shelved plans for a 3.4 liter.  May never get back to that.  

If I had it to do over again, I'd go with something much more "standard" and pay one of the L-series specialists to do it per their recommendation.  If this engine blows up, I will pay one of the well known L-series specialists to build a reliable replacement engine.  

Here's hoping this one doesn't go boom.



 


 

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Thanks Rossman.

Work I plan to do before I start this engine:

  • Installation and hookup of a full set of Speed Hut gauges
  • Installation of a larger capacity aluminum radiator
  • Installation of an electric engine cooling fan to replace the clutch driven cooling fan
  • Installation of a dry sump oil tank
  • Making and installing all of the lines associated with the dry sump system
  • Installation of a smaller battery (perhaps lithium) to facilitate the installation of the dry sump oil tank in the engine compartment

I've kept busy for the last five years with a 240z restoration project which I have been posting about over at www.classiczcars.com.  That one is currently awaiting paint - literally, as in nothing left to do but spray it. 

My Z project cup runneth over.  

 

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I found a few minutes to mock up fitment of the new radiator.  This one is made by Griffin.  It is three inches thick with 2 rows (1.25 wide each I think) in the core.  Size-wise, it is a pretty good fit.  This will be replacing the JTR setup I had in the car previously.  Before the engine blew up in August of 2015, I recall seeing the temperature needle on the stock temp gauge going slightly above its normal position.  This radiator should achieve an improvement with regard to that issue.

 

IMG_20230806_210823.jpg.805a9b3a3755f1d0023c7ef6b2c662ff.jpg  IMG_20230806_210849.jpg.551ed11c852a274dc63e318857f6ead6.jpg

 

IMG_20230806_210837.jpg.221e6ed2e807f9fd31d71ee317a424d5.jpg  IMG_20230806_210907.jpg.f4ee08e00410d1acc64bbb104a6441f7.jpg

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  • 3 weeks later...

As a Nissan/toyota/lexus dealership technician who's seen every possible assembly mistake (mostly by fellow coworkers), I'm wondering if the loose main bolts were the result of hydrolocking of the bolts while torquing the main bearing caps.

   

"Hydrolocking" of RTV or grease or assembly lube will give you those satisfying clicks on the torque wrench and then "bleed down"..........especially when the engine is run.   

Might take minutes or weeks.   

 

I'm not implying you guys are sloppy like the work I witness daily.     Quite the opposite. 

 

I've spent the last 5 years doing what toyota calls "Special service campaigns" on Toyota 86/scion FRS flat four FA20 engine and it seems to be the car that separates the guys who post big hours doing brakes all day from the guys who can assemble an engine correctly.   

I've even seen more than 10 cars where the flat rate guys smear "FIPG" (toyota's RTV) all over the valve cover gaskets and get some into the bolt holes.     Once they tighten down the valve cover bolts or cam housing bolts, enough pressure is generated to blow out where the hole ends leaving quarter sized 10mm wedge shaped chunks of cylinder head that eventually find their way to between the cam and a camfollowing cup. 

 

It only takes a little bit of oil to cause disaster.

    

I've also seen it happen on crank bolts so I'm now off to post this there.

 

Edited by HowlerMonkey
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