pparaska

The spline count and diameter of the splined section of the 240Z and 280ZXT stubs are the same, but I don't know if it'd be worth while, especially since there's a diameter DECREASE from the 240 to 280ZXT in that bearing area.

What's the static and mechanical timing like? Also, are you sure you don't have a vacuum leak?

Miles, congrats on the install! One thing troubled me in your write-up. You said "they are within 3 degrees" (the trans and differential). I hope what you meant is that the u-joint angles are both 3 degrees, and the same, or that the trans and diff are both 3 degrees relative to the horizontal plane (both in the same direction). The U-jont angles really need to be within 1 degree or so of each other or you can get some bad vibes, etc. I have an extensive write-up on my site under "Drivetrain Mods". I'm not sure what you meant and posted this for your info/query but also to bring this somewhat neglected topic up to those doing V8 swaps, especially with the JTR or MSA mounts. The Scarab placement, with it's higher and forward engine location, exhibits much less of a problem in this area.

RXO, The 400 balancer has material "missing" from the outer circumference, around only part of the circumference. It's amazing what you can find on google.com's image search engine. I typed in "400 harmonic" and found the following: Notice at the 9:30 position at the back part of the outer circumference. You can see where the material is seemingly "missing". [ October 30, 2001: Message edited by: pparaska ]

Very sad IMO that nothing in that article said they would try to build cars that people want to buy. Ford's market share dwindles and all they can do is worry about finances and other "essentials". If you don't build decent quality autos that excite people, you won't out sell the next guy. Daimler Chrysler seems to have learned this, and it looks like Lutz may have a hand at bringing decent products to fruition at GM. Unless the Ford dude understands what makes people want to buy, he'll not fare well. Let's hope - doesn't seem to be much of a car guy to me - just an evironmentalist/accountant type.

358 rwhp! 422 rw ftlbs! Awesome! What kind of intercooler?

Rebello? Hope you've got lots of time and money! Turbo it and the high end machine work/porting/etc. won't be needed!

I'd love to hear what kind of duration, valve spring seat and open pressures you guys run to rev AND MAKE POWER at 8 and 9000 rpm! That CAN'T be very streetable, but maybe that doesn't matter to some people. I realize that OHC the valve train is lighter, but are the valve spring pressures light enough for a 9000 rpm capable spring such that it doesn't wear the cam out in 5000 miles? If it revs to 8000 or 9000 rpm, AND MAKES POWER THERE, where's the torque peak?

Not the firewall, just a very minor (light swing of a 3 ) on the tunnel in one 4"x4" spot. Very easy and hardly noticeable. This is with an HEI and about 3/4" between it and the firewall. Move it back more and the Lakewood will need more clearancing in the tunnel.

Call me paranoid, but I've always thought it would only call attention to my car by the Constable if I had "50 killr", "IEAT50", etc. on a license plate. Van, what do you think?

OOh. Sorry, I forgot the topic was a roadster. But if you did it, I'd still support the shell well if not on the frame, and matbe some support for the top of the firewall as well.

It could be a 350 block, but a turned down 400 crank, making it a "383". IF the crank was not internally balanced ( a good bit more money to do to a stock crank, and usually not worth it), then it would have a 400 balancer and flexplate. The balancer is hogged out on part of the circumference, so that should be easy to tell.

Jake, I had forgotten that my Lakewood blowproof would rub if I went further back as well. As it was, I had to bump the tunnel near the firewall on the passenger side as it was (but only 1/2" in).

Glad you joined us grumpy! There have been a few tha have done the early Z31 (84-89) 300ZX SBC conversion, on is "Dr. Pete" Bomgard (SP?) that's posted here before - search and it should come up. "scarp" on this site has bought a later model Z32 300ZX with plans for doing a SBC V8. I think it's been done elsewhere as well. Frame strengthening - I put in custom subframe connectors - look at "structural mods" on my site. Others have done this and a few are working on tube frame chassis. Many here do 6 and 8 pt cages, if not more (Mike Kelly is at something like 22 pts, last count.) Of course, strut tower braces front and rear are a benefit. Miata seats are fairly cheap and fit well in the old Z's. Sparco has some race seats that fit and aren't obscene in price. Again, welcome! I'm personally really glad that you've joined!

Any idea what the volume of the dish is? I guessed 12cc as the dish volume, a standard 4.000" bore, 0.025" (typical) deck height (below the deck) and 64cc's and got 9.4:1 with 0.018 compressed thickness steel shim gaskets. Just keep at least 0.035", but not more than 0.060" piston to head clearance and you're in good shape for quench. My calcs don't include crevice volume, but it's typically 1cc, I believe. So 12cc could be 11cc in the dish, 1 in the crevice. Decking those heads that much sounds like alot. Is that safe (is there enough deck thickness in those old heads to allow that?)

Canton has a pan that is (I believe) 6.5" deep. It's very difficult to go shallower than this with a wet sumps system with good results.

Not sure which of those is better of the brands. Yeah, if it's not any extra work, why not, except to access the back area of the engine for one reason or another. Also, it may move the trans back far enough that the JTR trans brace doesn't fit in the tunnel, but you could plan for that when making one up. I'm using the HEI and to tell you the truth, the engine is close enough to the firewall for me. I have some ground wiring going to the tranny to engine bolts, and they are not easy to get to. Plus, working on the oil pressure switch, and other fittings at the back of the manifold is tight as it is. I'm just saying there are a few minor inconveniences for slamming the motor all the way back as far as you can. It's a trade off, only you can decide.

There are alot of loads carried by the firewall, both static and dynamic. The only way to do this is to support the car on a jig prior to cutting it out, and then make darned sure you have adequate thickness to carry the loads and tie it in well. This will be difficult to do with AL, since you need to tie it into the cowl area ate the bottom of the cowl space approx 6 inches below the hood level. I'd just get a piece of AL of stainless that spans the entire area and put it in there for cosmetics.

That's correct. By rim, I mean the highest part that would be closest to the head. And yes, use a piston stop to find TDC accurately and calibrate the harmonic balancer/pointer, or better yet, use a degree wheel. If you just turn the motor over, you'll squish the clay to minimum thickness and not need to do that though.

You should probably invest in a few books: Two I have that are decent: "How to Build the Smallblock Chevrolet" By: Larry Atherton, Larry Schreib "Small-Block Chevy Performance : Modifications and Dyno-Tested Combinations for High Performance Street and Racing Use" By: Dave Emanuel, Jerry Hensley You really need to check the deck height of the pistons before you go with that steel shim gasket. Even a lump of clay on the rim of the dished piston, put the head on and snug the head bolts (no gasket), then measure the clay thickness will give you an estimate. If it's less that say .020", the 0.018 steel shim gasket is too thin. I've heard there's a 0.024" gasket that GM has that may help.

1/2" or 3/4". That's probably equivalent of having 8 vs 10 gallons of gas in the tank. I doubt it's worth worrying about for mor that 1 second.

Kim, I agree that the two drawbacks of the JTR are important and should be spelled out in the manual. 1)oilpan and auto trans pan clearance and, 2)driveline angles issues. I've addressed both of these issues in my conversion. For one, I'm using and old style 6 qt Corvette pan (PN 359942, discontinued). It's about 7" deep, vs 7-5/8" for the standard SB pan of that era. Every little bit helps. Since this pan could be even shallower, is discontinued, and some Z's will be used for hard cornering at speed, I'd suggest anyone doing a JTR swap to consider the Canton 6 qt baffled and trap doord 6.5" pan. Do it before you have your exhaust done too. There's a 5 qt version, PN 360866 for the old corvettes (63-79 also). I wonder if it too is shallow, like the 6 qt pan. 2) The driveline issue is important. I had to leave out the frame-to-crossmember 1/2" spacers, adjust the trans tail height, and raise the back of the R200 by about a 1/2". This got me to 3 degrees of u-joint angle. If I loose 3 hp, I'd never know it. It's within the range of acceptable angles for the power I'm delivering, according to one driveline specialist source. Yes these are issues, and they should be mentioned in the JTR manual, I agree. But they seem to have fairly simple remedies (unless one insists on 1 degree u-joint angles). Since the internal rail manual trans conversions really require a JTR type placement, I think we must keep this all in perspective. Not everyone wants an automatic.

I think we've seen that link before here - great site. One thing I seem to remember is that the flat bottomed , raked approach depends on some pretty low ride heights to get a decent effect - possibly too low for speed bumps, etc.

Kim thanks for that description/analysis. Kinda wish I had a mechanical 750 now. BTW, you can convert the 3310 to have a rear metering block with jets. But you still wouldn't have the accel. pump.

Kim, thanks for that info on vac vs mech. secondary 750 holley's. If you were 98% street, would you pick the vac secondary (3310) or the mechanical (4779)? I guess if you set the tip in for the mechanical at 3/4 pedal or more, and learned how to not tip into it unless you were at 5000+rpm, the 4779 would be fine on the street.