pparaska

When I had an L24 in my Z, I had Motorsport Auto's 2.5" system on it with a Sonic Turbo muffler in the back. It droned like crazy. I added a 2.5" bullet muffler in the tunnel (it had two pipes in it and was packed with fiberglass, more of a muffler than a glass pack) and it help ONLY a little. Be careful with pipe sizes. If you only need 2" or 2.25" for good flow, stay away from 2.5".

Yeah, we all know it's not a "True Z", but some kind of fake thing not worth having if it doesn't have a Datsun or Nissan engine in it...

Naw, not at all. Engines like a carbed SBC are really simple. You'll get the hang of it!

For a number of reasons, even with the clutch depressed on a properly set up car, there will be some torque transmitted. Viscous transmission of force from the spinning flywheel/PP will make it turn, as well as any contact from a slight bit of wobble in the disk due to fit on the input shaft, etc. Another cause is improper alignment of the inputshaft into the pilot bushing. This can put a side load on the tip of the input shaft, turning the shaft even without a clutch disc present.

Andy, I've been dreaming about using that block as a starting point also. But isn't it siamesed, like a 400? Then you'd need the steam holes, but that's just a few holes to drill in your heads. No biggie. If you got the cash, that sounds like a platform to build on for YEARS. And the fact that you could start out with the STD bore, and have 2 or 3 overbores still available in the future makes it sound like a not entirely crazy-expensive way to go. That thing is supposedly very rigid and you'd not have a worry about strength or longevity. Add me to your "crazy" list .

I have that switch and it works as advertised. I wired it according to their instructions - opposite terminals are closed when you have 7+ psi oil pressure.

- I'll mention that to Jim the next time I talk to him How about the clutch arm is not engaged correctly on the pivot and/or on the release bearing? I've had that happen before, when a retainer spring broke.

Kevin, that was the cam I had initially decided on, but the first Comp Cams Help line guy tried to talk me into the smaller one. Got it today - the driver was all wide eyed as he handed me the box and we were cleaning the engine block on the stand, and then asked if it was going in the Z. If I ever find a pre-77 Volvo 240, I'll be doing a Chevolvo for my DD.

AL, I'm kind of sorry I had suggested doing a compression test in a recent email - very sorry that I lead you to this problem. Or maybe I'm glad you (might?) have found it. Is that difference in compression enough to cause all your problems though? I had an L6 with a bad head gasket that had two cylinders down at 100 psi, while the others were 135ish. It was a dog, but didn't backfire, etc.

If you don't mind a little algebra: Polar moment of inertia = radius*radius*mass Thiss is the effect on total PMOI due to a point mass (all objects are assumed to have all their mass concentrated at their center of mass). So moving a 525 lb engine (rough estimate of a SBC) from 3 ft (my wild ass guess) from the CG of the car to 2 ft 8 inches (a move of 4 inches) means a difference of: PMOI (Scarab) = 36inches * 36inches * 525lbs = 680400 lb*in^2 PMOI (JTR) = 32inches * 32inches *525lbs = 537600 lb*in^2 or a factor of : PMOI (JTR) ----------- = 0.79 PMOI (Scarab) Now, mind you, the moving of the engine will move the CG of the car, but I left that effect out. Interesting though, the contribution of the engines weight on PMOI has a pretty health influence on the PMOI. But my numbers are guesses here. I mainly ran these numbers to show that the distance that an object is from the overall CG is a SQUARED factor, and this is not insignificant. If I only knew what the PMOI of the entire Z was, I could get a feel for what the real effect of the Scarab vs JTR placement was. That oil pan clearance issue is not to be dismissed. For that very reason, I bought a now NO LONGER AVAILABLE 6.5" deep 60's Corvette 6 qt pan to put on my engine, so it would be at the same level as the crossmember. I too dread hitting the oil pan on a speed bump. At least my blowproof bellhousing will hang down lower than the oil pan now! That MIGHT help. [ October 13, 2001: Message edited by: pparaska ]

So, I have no original ideas, huh!? I was trying to think of the name of that company. Are you pulling my leg?

Kevin, the cam is new and not in the 2000 catalog, but on a press release on their web site, and in their online CamSpec database: Comp Cams (XS274S-10, pn 12-677-4) 274/280 deg. adv. duration (236/240 deg @ 0.050") 0.510/0.501" lift, 110 deg. LSA, Extreme Solid Flat Tappet Cam Cam Specs (Note the spring PN is incorrect, should be 986-16) After much discussion with various experienced hotrodders, etc., and calls to the Camhelp line several times, I'm pretty well convinced this will be streetable. Several on the Camhelp line, and notably Jaime (what a sultry voice she has ) supposedly one of their best cam selectors, says this cam should work great with my setup and application (hot street), and not need a vacuum canister. They expect a 2200-6200 power band. (However the first one I talked to said to use a cam lower on the duration/lift.) You need to deduct 6-10 degrees of 0.050" duration from a solid cam's specs to get to comparable hyd. cam specs, so this should be darn near the magic 225@0.050 streetable max duration. Remember, it's really the intake closing point that dictates dynamic compression and low speed throttle response. I feel that the whole "duration@0.050" thing is overblown, because it does not take into account the newer fast opening ramps, and the earlier closings that they afford for similar "0.050" durations. IVC is a much better place to look, IMO. I was assured that a cruise rpm of 2100 in 5th would not lug, which was my primary streetability concern. It should lope at idle (I like that, actually!) but have decent low speed torque in the ranges I need (26" tire, 3.73:1 gears, Tremec TR-3550 5spd). Desktop Dyno is guessing 400+hp with my combo, but I'm guessing it's a bit optimistic. BTW, I never did hear from David Vizard. I had sent my usage info and CC info to him through his web site http://davidvizard.com , but I never heard back. Good thing they didn't process my CC number, as I've made my decision without them! This time, I left nothing to chance and pulled all the water and oil plugs out myself first, and the only parts left in the block were the cam bearings. They even put the easy-to-overlook plug in the vertical oil passage that goes down to the oil filter area, that makes sure oil gets filtered (seen through a hole next to the rear main bearing). This is a reputable performance engine shop. At my request, they left the plugs out, but probably decided to put that one in incase I missed it . I have the brush set and I will be going over the passages, etc. with a very close eye this time! Mike C, thanks for that info. I am starting to lean toward the Vic Jr. first. [ October 12, 2001: Message edited by: pparaska ]

quote: Originally posted by Evan Purple240zt: ...I used to "frown" upon V8 conversions because i was hardcore datsun. Well im still an inliner. I have learned that the badass thing about the z is how versatle is can be. You can fit ANYTHING in that engine compartment!!! I love the z for its lines, and possiblities. Not what it was when it was produced! What we see here is a purist (hardcore brand guy) converted into a hotrodder! This doesn't happen easily! And only thanks to people like we have here at HybridZ does it happen. Certainly, places like that other "site" we visited lately, with idiots like Sheepman, will NOT foster this kind of free thinking and won't open any minds. I just LOVE seeing minds open! Evan, the words you wrote could have been written by any "hot rodder" or "modifier" of any car, starting back in the 30s and 40s with the jallopies they built with old Fords, etc. to the guys who buy a brand spanking new Vette, Camaro, Mustang, Honda, BMW, you-name-it, and say to themselves "Now, no holds barred, how can I make this thing REALLY rock!" When a person takes down the silly idea that a car should have only aftermarket or parts manufactured by the factory that produced the car, then the world of performance is wide open to them. It's almost a religious experience, no? Anyway, I see no problem with a turbo 4, turbo 6, V8, etc. as long as one realizes the strengths and weaknesses of each and factor them into their desires/needs/uses.

Thanks John. For me this is a release, a hobby. If I screw something up (that's happened enough) or decide on a different path, it's more money and more time. Oh well, I could be golfing, I guess, but I have few interests outside of cars and family. I'm really looking forward to preaching to my son how an engine works, how it goes together... nah just kidding! I'm pretty psyched that he's interested and we can do something together that I like as well. Hmm. I just had an idea for a new kid's toy line: Plastic Engine Stand Plastic Engine Blocks, pistons, rods, heads, etc. Plastic Engine Hoist. All simple enough for a 3 year old to work on! Somehow I doubt Playskool will be interested... [ October 12, 2001: Message edited by: pparaska ]

Nice list of cars! Welcome! For chassis mods, a 6 or 8 pt cage is usually suggested, as well as some subframe connectors. I have plans for some on my site (below) under "Structural Mods". Brakes and suspension also need upgrades if you're doing anything other than a very tame V8. There's lots of stuff on this in that forum on this site. But I'd suggest going to the HybridZ store from the main page and checking out scca (Mike Gibson's) brake kits. HTH,

I expect to have the motor together in a few weeks. The shortblock should be together by Monday, but the heads (461's) are with a friend who's doing a mild bowl port to them. He's done many that have been flowed and did well, and he needed some cash, so I said what the hey, another 30 hp or so would be nice. My biggest dilemna with the engine is whether to put the Holley 300-36 Dual plane back on (supposedly good from idle-7000 rpm) or the Victor Jr. I got from Mike Kelly. My gut tells me that if it only gain 10hp at 6000rpm with the Vic Jr, but lose 15 ftlb of torque and some throttle response (especially with a slightly lopey cam) over the dual plane, the Dual plane should go on. But then I keep hearing that the Vic Jr is a great street manifold and works well down low. I guess I could try each, and run them at the track or use a G-tech (need to get one of those) to compare them. This morning, my 8 yr old son, who's NEVER shown any interest in cars or the Z asked when it would be finished. He wants to go to the drag strip with me and watch me run it. I think that was the biggest incentive to get out in the garage I've had in years! I think I'll get him out in the garage with me to show him how an engine goes together this weekend. But I plan on having the drivetrain back in the car in a month or two. I still have glass, interior, latch hardware, trim, bumpers, lights, etc. to install. Barring any unforseen holdups, I think an early Spring launch is easy. Then I'll get to work on my website - it needs a total makeover.

Just thought I'd give you guys an update. Remember my crank and bearings were scored after an hour of running the engine in? I was wondering if the body shop guys ran the engine when I thought there was no oil in it. (I had disabled the starter and ignition and THOUGHT I'd drained the pan so it would not leak on their floor.) I was also wondering if a follow-up machining process left crap in the oil passages that got past the engine shop's cleaning and I never double checked and cleaned. Neither! I pulled the rear galley plugs out of the block and found flakey rust in the back inch or so of the walls of the galleys. What must have happened was either water (condesation) or hot tanking fluid sat in the back of the galleys while it sat on an engine stand for years while I worked on the car. If I had just run oil through the engine and prelubed it after I built it, this wouldn't have happened. So when I finally prelubed the engine after installing it, the flakey rust broke loose and went straight to the cam, main and then rod bearings, even before getting a chance to go through the no-bypass filter setup. Expensive and time consuming lessen. Boy, I feel stupid. I took all the oil plugs out and cleaned things up, and then I just had the cam bearings removed, the block hot tanked, and new cam bearings installed. Got it back Wednesday. Of course, I just ordered a bigger cam - can't leave well enough alone! (The CC 270 Solid Magnum cam was MILD - it will have a 274/280 Xtreme Solid flat tappet cam now). I have all the parts now to put it back together, and will start on it this weekend. Oh, and I ordered the Carter Street (4-6psi) electric pump to replace the old Holley Blue pump that was making WAY too much noise. I also got some isolators that Carter sells for mounting the thing. Oh, and I got a Pro-Comp Indash Speedo to match the rest or the gauges. Anyone interested in a stock 240Z speedo that reads all Zeros on the odometer? The rest of the car has made little headway in the time it's been back from the shop. Family life has kept me busy.

Uh, SpencZ also left HybridZ a while ago. Last I heard he still had the car, but was going with a hopped L6 instead of a V8.

Everything I've read says a bit of tweaking of the L28T will get you in the 12s. Not sure how much or how expensive, but it sounded simple and somewhat low budget. If this is true, this would be a cheaper and easier way to get into the 12s than a V8 conversion. Of course, the V8 has other attributes that might make it enticing to some of us. Like the easy of getting into the low 12s and 11s.

Just remember, that big old clunky V8 can be built low performance and be stone reliable and still move the car with authority. The smaller you go in displacement, the more boost or rpm you will need. Not a bad thing! But you have to know where the trade-offs are. BTW, SB Ford V8s are lighter than the L6. Generalizations will ALWAYS get you in trouble. It's not my cup of tea, but a tweaked 4 cyl turbo motor could be very fun - especially on the track. On the street, I'll take the low end torque and low rpm throttle response any day. Hard to do with a small turbo motor (2.0 liter).

n/m

There is info in the JTR manual about using a GM throttle cable. I used a Lo-kar universal one - looks good, works great. The 280Z seats should bolt right in, AFAIK.

I can't remember the details of all the rest of the circuits, but I DID map out the entire harness of my 73. The headlight circuit was the weirdest part I remember. That and not using relays hardly anywhere they should have!

Jim, You've found out the Datsun Headlight Secret. The dude that designed it was a high school flunky, no doubt! Yes, the headlight on/off switch sends +Battery voltage to the common of each headlight (through each fuse). And the hi/low switch sends the ground to either filament. It's got to be the stupidest wiring of headlights I've ever seen.

Hi Kim, Sounds like a heck of a ride. I can't exactly remember your last name, but I do remember you from the IZCC list from years ago. Can you let us know what your web URL is? The one in your profile is hosed. Cheers, Pete