kj280z Posted June 23, 2010 Share Posted June 23, 2010 Hey all, I have a set of the headers pictured below - The website states: The LS1 shorty headers are designed to fit into the 1970-1978 Datsun Z cars using the LS1 engine. These headers will work with the John's Car LS1 mounts. The primary tubes are 1-3/4" and the collectors are 3". The fit on the driver's side is very tight. The header on the driver's side requires trimming one of the bosses on the engine block. The header on the driver's side must be installed from underneath the car. The spark plug wires need to be changed to 90 degree boots. 90 degree boots are used on LS2 engines. My comments: 1. No they do not fit (haven't even tried the passenger side yet because the drivers side isn't even close to fitting) 2. I can't see what they are talking about with the instruction of "The header on the driver's side requires trimming one of the bosses on the engine block. " Maybe its because mine interfere with the motor mount so this has not become apparent yet??? 3. Further on number 2 - the headers interfere significantly with the JCI motor mount near the TC cup - fixing it to make these work will require removing the mount, cutting a larger section of the corner off, making a new section for the portion of the mount that will be weakened and welding it all back together. 4. The header comes way too close for comfort to the steering rod I'd LOVE to hear some suggestions and solutions that any of you have implemented to work around this!! Please enlighten me! http://jagsthatrun.com/Pages/Parts_DAT-Z_LS1-Headers.html Quote Link to comment Share on other sites More sharing options...
Cable Posted June 23, 2010 Share Posted June 23, 2010 You might have the wrong headers. I've done many LSx swaps into S30's using these headers (and JCI's mounting kit), including on my own S30, without a hint of the issues you are describing. Quote Link to comment Share on other sites More sharing options...
kj280z Posted June 23, 2010 Author Share Posted June 23, 2010 You might have the wrong headers. I've done many LSx swaps into S30's using these headers (and JCI's mounting kit), including on my own S30, without a hint of the issues you are describing. Mine are identical to the ones in the picture - What else could it be? Quote Link to comment Share on other sites More sharing options...
jasper Posted June 24, 2010 Share Posted June 24, 2010 Question; Are you using the top, or bottom header (reference picture), for the DRIVER's side? Quote Link to comment Share on other sites More sharing options...
SUNNY Z Posted June 24, 2010 Share Posted June 24, 2010 (edited) Yep, there is no way they'll fit. Sell them to me for $100. Problem solved In all seriousness, make sure you're using the correct header. SIDE NOTE: for $500, don't you think they could use their high and mighty abilities of building headers to produce a long tube! JEEBUS, that kinda coin for shorty headers makes me scream Edited June 24, 2010 by SUNNY Z Quote Link to comment Share on other sites More sharing options...
kj280z Posted June 24, 2010 Author Share Posted June 24, 2010 Question; Are you using the top, or bottom header (reference picture), for the DRIVER's side? The bottom one in the picture is the drivers side - unless you put that on the passenger side and have it point toward the front of the car... I've been out there trying different things for an hour and getting real frustrated... I have a set of stock 2002 Camaro cast iron exhaust manifolds and with a little massaging to the flange I believe it will fit better than these headers!! (I've only looked at the drivers side... no idea on the passenger side yet.... Anyone have some pics of these headers installed in their car? How much clearance do you have at the corner of the drivers side motor mount? Here's some pics: In this pic the section that I marked with a black marker would need to be cut off (the headers are 1/2" away from the head due to the clearance problems I can't get them to mount up close yet) Another pic from the top for reference: Quote Link to comment Share on other sites More sharing options...
emeraldlion Posted June 24, 2010 Share Posted June 24, 2010 I'm not sure if this would cause an issue, but do you know if your z has had any accidents in the past that might have tweaked things? Quote Link to comment Share on other sites More sharing options...
kj280z Posted June 24, 2010 Author Share Posted June 24, 2010 I'm not sure if this would cause an issue, but do you know if your z has had any accidents in the past that might have tweaked things? I know the entire history of the car and have also had all measurement points confirmed on a laser frame machine - it is perfectly on factory spec... I have gained some ground on this problem - I found the the JCI mount wasn't clearing the small hump on top of the TC reinforcement. I had taken an air hammer to it but there was more to go... It still hits, but now it only requires a 1/2" of material to be relieved off of the corner of the mount... I am finished for tonight and will continue tomorrow... If anyone has any pics taken from the top down towards the corner of the JCI bracket with these headers installed, please share! Also, I really appreciate all the responses and suggestions! please keep them coming! I gotta get past this issue so I can finish this project up before the convention!!! Quote Link to comment Share on other sites More sharing options...
Dudeboy Posted June 24, 2010 Share Posted June 24, 2010 (edited) kjones, I am searching on another computer for the picture, but I have this photo for you. I had to remove material off the lower control arm with a grinder and a dremel tool. I had buddy come over weld in a steel plate were we removed the corner of the LCA. What i did not realize was my transmission tunnel needed a couple of more hits with the BFH ! The 4L60E was butted against area a little deeper into the tunnel. We are talking literally a few more whacks in the tunnel would have gave that 3/4 inch to 1 inch clearance for the driver side header to fit. So i did number three in your response. Edited June 24, 2010 by Dudeboy Quote Link to comment Share on other sites More sharing options...
kj280z Posted June 24, 2010 Author Share Posted June 24, 2010 kjones, I am searching on another computer for the picture, but I have this photo for you. I had to remove material off the lower control arm with a grinder and a dremel tool. I had buddy come over weld in a steel plate were we removed the corner of the LCA. What i did not realize was my transmission tunnel needed a couple of more hits with the BFH ! The 4L60E was butted against area a little deeper into the tunnel. We are talking literally a few more whacks in the tunnel would have gave that 3/4 inch to 1 inch clearance for the driver side header to fit. So i did number three in your response. Thanks - I did raise my tranny as well tonight and noticed the same thing on my T56... The pictures were helpful - much appreciated, but I'd love to see some closer detail on how much room is down there... It appears thatyou have about a 1/2" of clearance if I am interpreting the picture correctly. One other thing - Just a comment, but after having taken that header in and out at least 20 times now, it would sure had made life easier for all of us if they had relocated the collector back a little further - there is a TON of room and it appears they still could have achieved equal runner lengths - I'm not a big fan of the design for several other reasons as well... having a flange in that location will make it a total PIA once the exhaust is in... Anyone else have a different style of header that they would like to trade for these? (as long as they are a proven design that will fit with no headaches) - I'm all ears! Until then I will continue on to mold these against their will! <grin> Quote Link to comment Share on other sites More sharing options...
zgeezer Posted June 24, 2010 Share Posted June 24, 2010 I know the entire history of the car and have also had all measurement points confirmed on a laser frame machine - it is perfectly on factory spec... I have gained some ground on this problem - I found the the JCI mount wasn't clearing the small hump on top of the TC reinforcement. I had taken an air hammer to it but there was more to go... It still hits, but now it only requires a 1/2" of material to be relieved off of the corner of the mount... I am finished for tonight and will continue tomorrow... If anyone has any pics taken from the top down towards the corner of the JCI bracket with these headers installed, please share! Also, I really appreciate all the responses and suggestions! please keep them coming! I gotta get past this issue so I can finish this project up before the convention!!! I have the same headers installed with JCI mounts front and back. No interference with mounts: However, the headers would not clear JCI's oil pressure set up. ('70 Z with LM7) Quote Link to comment Share on other sites More sharing options...
Dudeboy Posted June 24, 2010 Share Posted June 24, 2010 It was a challenge getting the engine/transmission in and you are correct, I removed about 1/2 to 3/4 inch of material. Quote Link to comment Share on other sites More sharing options...
rags Posted June 24, 2010 Share Posted June 24, 2010 Here ya go. Quote Link to comment Share on other sites More sharing options...
kj280z Posted June 24, 2010 Author Share Posted June 24, 2010 Joe, In that last picture you posted, it's hard to tell, but it appears the left side of the collector also touches your motor mount... same as mine I have gotten mine to fit but it now just barely touches and I don't see any other choice but to relieve the JCI bracket above the TC cup... I am starting to conclude that the bracket fits higher on the 280Z than the 240Z (I took a look at my 240Z a few minutes ago) and thus with the ZERO amount of room that these headers provide there is no margin for error. With a VERY slight modification to the design of the header it would fit MUCH better... Seems like JTR is trying to hit a broader market with these so they don't care to tweek them to be optimal... I hear the JCI headers fit much better and move the collector back a little bit... FYI JCI is out of their headers and is switching vendors so they will not have any headers available until the new vendor gets rolling Quote Link to comment Share on other sites More sharing options...
kj280z Posted June 25, 2010 Author Share Posted June 25, 2010 (edited) Quick update - I have solved the problem... 1. The motor mount needed to have 3/8 grinded off the corner 2. There was an issue with the tranny mount where it had the motor too far towards the drivers side - had to modify it to correct the alignment 3. There was one spot where the tranny was hitting the tranny tunnel - it was hard to spot but I finally was able to resolve it by trimming a piece off the passenger side of the tranny housing With all this done, the shifter centers PERFECTLY in the stock opening. Note to all those that I have seen with their shifters coming up through the hole with it biased towards the driver side - look for issues with your tranny mount and/or clearance issues on the passenger side of the tranny tunnel... Mine was biased towards the drivers side as measured by the shifter about an inch - I have seen a bunch of you trimming the shifter opening which is not the greatest way to address this issue. One inch of misalignment in the drive line may just be enough to create some minor drive line vibrations (I don't know how many degrees of misalignment this translates to) - I did a search and found at least 5 examples of LS1 Z's having the drive shaft bolts come loose. I suspect in some of these cases you'll find that your shifter comes up through the opening on the drivers side... 1. Fix the tranny mount so it it aligns correctly 2. Relieve the tunnel and/or cut un-needed protrusions off the tranny so that everything clears properly After doing all this, even my steering shaft has much better clearance... Thanks for everyones help! Much appreciated! Edited June 25, 2010 by kjones Quote Link to comment Share on other sites More sharing options...
kj280z Posted June 25, 2010 Author Share Posted June 25, 2010 I have the same headers installed with JCI mounts front and back. No interference with mounts: However, the headers would not clear JCI's oil pressure set up. ('70 Z with LM7) Zgeezer - Mind sharing what you did with your oil pressure setup? I will be working on that next now that I'm past the header clearance challenge Quote Link to comment Share on other sites More sharing options...
zgeezer Posted June 26, 2010 Share Posted June 26, 2010 Zgeezer - Mind sharing what you did with your oil pressure setup? I will be working on that next now that I'm past the header clearance challenge Replace the LM7's stock oil pressure gauge sender [top of engine just behind the intake manifold) with an early Z sender. There is a difference in size and threads between the Chevy block and the Datsun gauge.... but there are a number of adaptors out there (See summit and anyone that sells gauges for foreign cars) . I have the JCI mounts and it appears there is plenty of room between the firewall and sender for clearance. I think JKI mounted the sender off the Gen III pan because it was closer to the stock oil pressure wire from the Z. Not done yet, but I'm 95% certain it will work. G Quote Link to comment Share on other sites More sharing options...
Savage42 Posted June 26, 2010 Share Posted June 26, 2010 FYI JCI is out of their headers and is switching vendors so they will not have any headers available until the new vendor gets rolling Let's hope they make up a set where there aren't spark plug wire interference issues, as well. That's just stupid!! Quote Link to comment Share on other sites More sharing options...
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