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Looking for engine suggestions!


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Guest Anonymous

Pete, thanks for the info, your page and car look great!

 

I am also thinking 327 because of my desire to have a little more room on the top-end rpms. The old-fashion build up seems cheapest and easier than going with an LT1.

 

I will probably go the "fake" 327 route through the 350 4-bolt block and 305 crank route to keep costs down and increase availability of parts. All aluminum is the way to go, do you or anyone else know if there were other SBC blocks that were aluminum from the factory?

 

As for Ford small blocks, my only concern is the modification necessary to get it into the Z. I saw the web page done by a fellow hybrid member that discussed the modifications, but they seemed overly extensive. Further, it may cost more to build the Ford motor up for my purposes than an equivalent 327.

 

Thanks again!

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Roamer, Thanks for the compliments!

 

No AL old style SBC block from the factory ever (that I've ever heard of in 23 years of hotrodding), but there are some aftermarket ones out there that are expensive as hell. Not worth the savings. They are usually beefed up so the weight savings goes down as well. Trick, but pricey. Add the weight savings is less than 100 lbs, I've read.

 

From : http://www.mortec.com/borstrok.htm

302 = 4.000" x 3.00" (5.7" rod)

305 = 3.740" x 3.48" (5.7" rod)

307 = 3.875" x 3.25" (5.7" rod)

325 = 3.780" x 3.62" ('99-later "LM7" 5.3 Liter Vortec)

327 = 4.000" x 3.25" (5.7" rod)

350 = 4.000" x 3.48" (5.7" rod)

 

Note that you'd need a 307 not a 305 crank to do a large journal 327 with a 350 block. Probably not easy to find. There were large journal 327s made in 68 and 69, also rare. (Ross has one!). Anyway, you'd probably want a large journal crank to use large journal rods, although there are some good aftermarket rods made in small journal sizes, and special bearings are available to put the small journal crank into the large journal block. I believe I've seen aftermarket cranks in 3.25" stroke also, but all this aftermarket stuff CAN (not always) be pricey.

 

Don't discount the idea of a light pistoned 350 though. Built with light forged steel rods and light pistons, this motor can rev quickly as well.

 

------------------

Pete Paraska - 73 540Z - Marathon Z Project

pparaska@home.com

Pete's V8 Datsun 240Z Pages

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Guest Anonymous

Pete, thanks for clearing up my misconception about the 327 issue. Given the difficulty of finding a large joural 327 I will stick with a 4-bolt 350 to help keep costs down if I decide to go to Chevy.

 

Given my last sentance doubt is in my mind about a SBC. The weights I have seen put the engine in the 560lb range, VERY heavy. If I go to all aluminum on top I can lose maybe 75 lbs, but it still weighs more than the L28. Further, it looks like I would have to go 6-speed to get a tranny that works with the engine specs I am looking at, requiring further modifications to the tunnel.

 

No one has brought up a 302 conversion, I was wondering why. I know that the 302 is not as standardized as for installation into a z, but fabricating motor mounts and relocating an oil cooler should not be overly difficult (my father-in-law is a tool and die guy for Ford). Furhter, from what I understand the 302 actually weigh's LESS than the L28. I also personally know a nationally recognized Ford motor guy who could build up a 302. What do you guys think of this, rember I am going for road course racing and weight is equally important in gaining speed on the track.

 

Thanks!

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Been a busy thread since I last got in here! I'd heard my ears ringing;^)

 

Nothing wrong with building up an 'older' style sbc. I'd only do it if nothing current suited my needs though. Many on this list have built high $ motors for 425+ hp. Roamer, you didn't say you're looking for that and if you were you'd have to fully reengineer the WHOLE car to roadrace with that anyhow so we're at your ~300hp figure.

 

-sbc built is not VERY heavy as you say, and yes it may be slightly more than others but it's power comes so EASY and CHEAP (2 of my fav. words, right next to bang/buck;^), it's weight is in a nice/low location as well to help your polar moment of inertia (do a search of site if a new term) which is v. beneficial in any autox/roadracing

-I can't tell you what you want but IMO you won't need under any event to hold a sbc at 7k to roadrace it, with flat power/torque from 3k-6.5k (and broader depending on your build) their's just no need to run higher with a decent trans/gear spacing, if 7k makes the difference I"m sure a rev kit can be installed to gain that bit, it's a lot cheaper/easier/more suitable overall IMO to build the trans/diff/tire to meet your gearing needs than build a powerslide type 4k-10k rpm motor (those 2 spd setups..)

-given the ease of getting 3-400hp (400hp comes easily with simple mods) from an Lt1 and their relative availability with T56's which do offer a nice gear spacing that'd be a natural for me if I were starting from scratch and going with a standard as you are (I'm sure you can get an Lt1/T56 for 4k)

-or if you can come across any roller sbc block's (what's your budget/intents? $4k was it? for motor or fully motor/trans) and you want to add some bolt ons to a low mileage shortblock (what I did, easy 400+hp, 50/50 weight..)

-I wouldn't discount a sbc for what you've calculated as a weight gain (so many weight figures that go around), those few pounds you're talking are covered easily with small power increases (~5lbs for 50lbs). The EASY power and cheap/very available parts (whether any piston/intakes/wicked roadracing oilpans etc) more than make up for that IF indeed their is a weight gain (I'd argue that, as my steering effort/etc/weights are less than my car was OE)

 

I don't recall where you were (eastcoast?), I have a '68 327 shortblock that should be put back to use, and a PJ gear drive, and other stuff;^)

 

------------------

Of all the things I've lost, I miss my mind the most.

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Roamer:

-forgot to mention, tranny tunnel mods are minor and no more than an afternoon's work at most (some it was only 10minutes with a hammer), not aftereffects either

-found the URL for Ron Tyler's car (my dad now has his powertrain), good pics and some verbage to go with it, feel free to email Ron with any q's, he took an autox title the year he ran it and just took one this year with a different car I believe http://www.datsuns.com/cars/rontyler.htm

 

HTH

 

------------------

Of all the things I've lost, I miss my mind the most.

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Guest Anonymous

560 lbs isn't that big of a deal.... a l28t complete is 490. Add in an intercooler, oil cooler, and stuff like that and it could approach that figure. That 560 figure is probably a typical SBC without accessories though.... With so much power an extra 100 pounds isn't a big deal, plus done properly, the v8 will sit farther back and put more of its weight on the rear wheels, which will leave better handling.

For the money, I'd go stock lt1 with a t56. 6 speed, fairly lightweight, injected, perfect drivability, and still plenty of options for more power later.

 

 

------------------

Morgan

http://z31.com/~morgan/s30

http://carfiche.com

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Wow, don't read in for a little while and miss all the fun!

 

Coupla' things... Having owned a turbo V8, owning a turbo rotary, and owning a centrififul supercharged V8 - albeit not on the road, I think I can contribue a few things...

 

First - Mike the RAMJET 350 GM is selling is NOT a ZZ4 that's been modified. If you've seen something I haven't please enlighten me (I'll cry). The RamJet I saw had cast pistons - ick!

 

Second - turbo lag is a myth if the silly thing is sized right. My V8 had ZERO lag and made full boost (10lbs) by 3K - note that this was TWO turbos. My RX7 has sequential turbos - comples as hell but lag is pretty much not there in any reasonable driving RPM. It revs like mad too smile.gif Centrifigul blower - yeah full boost USUALLY occurs at peak RPM and there's some "lag" but at normal RPMs on a strong base motor it's no big deal.

 

So, why did I go from turbo to belt driven? Simple - it was complexity and packaging that pushed me. Turbo motors are GREAT but geez the heat and complexity is a bitch! I'll get about 600hp out of my 351W with the blower, do I really need more than that? I know someopne who's seeing 800RWHP on the dyno that drives his ATI blown motor on the street! blowers may not be perfect or super effecient but I'd say they certainly get the job done!

 

Someone stated that blowers are used for competion more often for the drag race scene. Look a little closer - turbos are showing up like mad in the Ford race scene because they make insane power! They don't show up elsewhere primarily because of rules and additional weight penalties. There used to be a 6cyl Buick turbo dragster that kicked many a rear end - it was penalized right off the track by all of the complaints from it's compeitors! Given an unlimited budget a turbo is the way to go. Most of us don't have that prerequisite though smile.gif

 

Lastly - high RPM. Personally I don't see the need for the high RPM here. However not that many OEM type V8s "redline" around 6K. The Ford 302 hits the limiter at 6200RPM but it CAN rev higher if the limiter is bypassed! This likely holds true for other V8s. I've seen "older" style SBCs revved to 6K without special parts, sure sounded nice. Yeah, it probably began floating valves but for an OCCASIONAL rev a well built motor should be okay. I believe someone already ststed that their motor had hit 7K on the dyno (shrug). Keep the rotating assembly light, use good rods and pins, pay attention to the valvetrain. Given a choice I'd try not to build for that high an RPM - 6K is more reasonable (shrug). Hear a V8 at WOT hit that RPM - you'll know what high revving music REALLY sounds like smile.gif V8s don't usually need to be revved real high to make power, if you're used to a GSR or say an RX7 driving a built V8 will be an eye opener I think. Displacement has it's advantages, torque out of the corner will be a really big one.

 

P.S. Why no 6speed? Weight? Rules?

P.P.S. Ever hear a rotary at about 6K? It sounds liek a baby drying under the hood - I have to laugh every time I hammer it, it's damned funny!

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Guest Anonymous

I think to be fair, a twin turbo V8 will have less discernable lag because of the added bottom end torque to start with. A small four with jack for torque to start with would be much more noticeable. Considering its a exhaust driven compressor, there has to be a split second before the exhaust pressure comes up and the turbo gets with it no? Also, although its not been mentioned, isn't the current generation of centrifugal blowers essentially exactly like a turbo on the compressor side? Only difference is its belt/gear multiplied to spool it up instead of exhaust driven?

Only bringing this up for discussion, not being a wiseguy and starting anything.

 

Lone

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Originally posted by Roamer:

Guys, I think you have me going toward the SBC, is there any real power advantage to going to a 327?

 

Roamer,

 

I too am a new member & greatly appreciate a site where we "Gearheads" can exchange our ideas & special interest in cars.

 

The reason anyone would want a SBC302 over the 350 is because of its shorter crank; the shorter crank allows for greater rev's.

 

You appear to be well versed in the supercharger -vs- turbo argument, therefore, I think I'm safe in assuming you are an avid reader of auto performance. Someone earlier mentioned David Vizard's book...it is an excellant book.

 

I have spent many a Saturday, & would suggest to anyone whose interested in increasing their SBC savvy to visit their local Barnes & Nobles Bookstore, Specifically their "Auto" Section. Dont limit yourself to just one of their stores: ask for any of their other locations as I've found some stores have large volumes of SBC info while others are not so large.

 

Extemely helpful books I've found on SBC:

 

1)Hot Rod series

a) Volume 9: How to Build BIG INCH SBC.

B) Volume 11: High Performance Camshafts

 

2)HPBooks: Popular Hot Rodding SBC Performance Trends (for Street & Racing)

 

3)HPBooks: Chevy Power-The Official Factory Pwerformance Guide.

 

4)HPBooks: Auto Math by John Lawlor

 

5)S-A Design's books on SBC Performance Volume 1&2

 

As you can see the list goes on & on regarding the SBC. The most informative books of the list I found were the High Performance Camshaft from the Hotrod series & the Auto Math.

 

The book on Auto Math has all kinds of neat formulas such as: Comp.Ratio, Piston Speed, HP/Torque, Prime Shift Points & loss of Rpms when Shifting, MPH-Rpm-Gears & Tires. I really have a hard time putting these two books down.

 

Hope this helps.

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quote:

Originally posted by Kevin Shasteen:
Originally posted by pparaska:

 

From :

302 = 4.000" x 3.00" (5.7" rod)

305 = 3.740" x 3.48" (5.7" rod)

307 = 3.875" x 3.25" (5.7" rod)

325 = 3.780" x 3.62" ('99-later "LM7" 5.3 Liter Vortec)

327 = 4.000" x 3.25" (5.7" rod)

350 = 4.000" x 3.48" (5.7" rod)

 

My two cents worth again:

 

For argument's sake, GM produced a large journal SBC crank with a stroke of 3.100 in the 262 cu.in. engine from 1975-76 as per the Chevrolet Small Block V8 interchance manual.

 

That stroke of 3.100 is only .100 larger than a 302 strok.

 

I dont know what performance your could obtain-it is a cast nodular iron crank. If you could find one in a bone yard & kept your engine mod's moderate-it shouldnt be a problem.

 

However; good luck finding a 75-76 GM Vehicle that hasnt been crushed w/the 262 still in it. These auto's were high on the crushers food chain as the low perf.cu.in's were not powerful enough to propel anything longer than a 110 inch wheelbase effeciently-thus they were only produces for @ 1 year

 

P.S.

 

Roamer; in my previous entry I forgot to suggest to you a video tape on SBC Hotrodding. It takes you thru the process of Prepping & Deburring a SBC for performance purposses: its produced up in your neck of the woods.

 

"American Muscle Cars Volume2: Hotrodding the SBC. 120 minutes

 

KLK Productions, PO Box 411, holmdel, NJ 07733

 

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Guest Anonymous

WOW!! We are really going here!!

 

Not to in any way discourage this great conversation, but I noticed that the discussion has floated back to turbo/superchargers but again I am looking to keep costs down as well as weight so NA is the way for me.

 

As for the polar intertia issue, I understand the advantage that the v-8 will provide, but if I can build a lighter v-8 motor I will have advantages in braking and cornering, you know those other pedals and parts in your car. wink.gif

 

We seem to be getting to far afield on straight line performance. In most of the SCCA events I will be running they are too short and tight to truly see the advantages that the slightly higher powered sbc might have over the Ford 302. Also, a 5-speed in the stang will most certainly weigh less than the T-56 in the LT1 set-up so again I am losing weight. (and I hate that 1-4 skip feature)

 

Today I will be calling that aforementioned Ford specialist to see what costs and weights will be for a 300+hp 302 (from a 91+ stang) and I will let you guys know what I find out.

 

If anyone has accurate numbers on the LT1+T56 combo, please let me know. I am leaning toward FI because it will be more reliable and provides greater flexibility when making mods.

 

Thanks!

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Sounds like you are taking a path, making a decision.. which is a good thing. However, the T56 1-4 skip shift is not an issue, as you simply just don't put any electrical power to the transmission(i.e. don't connect the solenoide). Weight might be though, as the T56 is about 32# heavier than the Nissan CompT5. It is a heavy sucker. If you plan not to push more than 350#ft of torque through your motor, the T5 will be fine. Also, going with a ford isn't a bad choice, just not well documented. You might want to Make Terry Oxendale your new best friend! Check his ride out in Featured rides and you will see what I mean!

 

As for light weight in SCCA, I'm assuming solo1 & 2? If so, go out to Marsh Racing and check their carbon/ aluminum 3 piece wheels. The weigh less than 10# and it is a known fact that the best thing you can do is reduce rotating mass. Get those wheel and tire combos down as light as possible and you might see more noticable improvement than going through the headaches of putting a V8 in the car (Did I just say that?) and being thrown to the wolves in the modified ranks!

 

Mike

 

------------------

http://hometown.aol.com/dat74z/myhomepage/auto.html

"I will not be a spectator in the sport of life!"

mjk

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Guest Anonymous

Roamer,

 

The 302 Ford is definately a viable alternative. Getting 300 hp will be no big problem. Expect to pay a bit more up front for parts. Its what I intend to swap into mine in a few months. The engine is lighter to start with and with some good aluminum heads (edelbrock or trick flow both are pretty decent out of the box) its a light potent package and its EFI has alot of aftermarket support.

 

Lone

 

[This message has been edited by lonehdrider (edited January 08, 2001).]

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ROAMER, JUST THOUGHT I WOULD LET YOU KNOW IF YOUR INTERESTED. ON EBAY THEY HAVE A DZ/302 SBC IN VERY GOOD SHAPE. BID IS AT 500.00, NOT BAD. JUST THOUGHT I WOULD THROW THAT OUT THERE. ITS UNDER ENGINES, ETC..

PAGE 8. PICTURES OF COMPLETE ENGINE AND NUMBER CODES ARE LISTED AS WELL.

 

GOOD LOOK WHAT EVER YOU DECIDE!

 

Z/FAN...MIKE

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Hey, nuthin' at all wrong with a Ford 302 combo! In fact these days I'd say that with the possible exception of the machine work you could almost put one together for LESS than a SBC. Seriously, there are TONs of 302 parts around. the Mustang has really built up a following - used parts damn near fall out of trees out my way! Parts availability isn't the issue - the lack of documentation on the swap is. That T5 is nice and light too and the stock 302 will take 6500RPM pretty easily - just remember the stock EFI rev limiter kicks in at 6200 RPM (ahem).

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Guest Anonymous

Hey guys this has been fantastic.

 

I think I am going with the Ford 302 option. I talked with the local Ford guy and the costs seem very reasonable, with a set of aluminum heads 300+hp is NO problem, he can build the bottom end and tranny to handle 7k and 500+hp without significant costs and he is intrigued about doing the swap! Not to mention he has FI 302's and trannys to use as donors that he knows the condition of!

 

I have yet to look at the z on ebay, but I am going there now! I did locate a z in Arizona that I might be interested, we will see!

 

I will keep you posted on my progress and thanks again to all for all of your help!!!!!

 

Marc

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quote:

Originally posted by Roamer:

Hey guys this has been fantastic.

 

I think I am going with the Ford 302 option. Marc

 

Marc, great stuff:-) You sparked a v. good thread and now we're all eagerly awaiting updates/pics and eventually driver feedback on your new creation:-) You'll definitely like that one and given your 'modest' power goals the weight savings of the 302 and some other advantages will be enjoyed nicely!

 

keep us updated smile.gif

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Guest Anonymous

I havn't seen anyone touch the idea of a turbocharged SBC 350. there are many kits out there for single or twin turbos. they work with carbureated or efi systems. personally i would go for a mid 60's 350, tear it apart, get lightweight heads, cams, intake manifold, 850cfm carb, twinturbo kit(comes with headers, turbos, ect), and intercoolers. the engine stock would have run 300+hp. after you do all of that, you'd have somewhere in the range of 500-600hp(maybe more depending on boost levels). very streetable. will cost 4-5k if you do most of the work. i've done all of that with the exception of the turbos to a 90 camaro and man what a ride!

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