here is what scout motors should look like. This is my friend Johann Cox's Scout, it is that really clean yellow one with the black soft top. He is about to spring it over, then it will be a "bad dood"
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here is what scout motors should look like. This is my friend Johann Cox's Scout, it is that really clean yellow one with the black soft top. He is about to spring it over, then it will be a "bad dood"
that is a gm tpi manifold and injectors, right? how did he rig it with the scout block?
***, that is because it is a GM motor. That's one way to put a Scout on a diet.
Looks good Jimmy, is that here in town?
is that the guy that's guiding on the king ranch now?
Sweet truck...I stopped and talked to him a few times...he built that thing on a tight schedule.
NO, that is NOT TPI, that's an LT1. Big difference.Quote:
Originally posted by stinger7401
that is a gm tpi manifold and injectors, right? how did he rig it with the scout block?
LT1 isn't tuned port? I thought if it had a dry TB, runners, and 1 injector/cylinder, then it was TPI?
dittoQuote:
Originally posted by uglyota
LT1 isn't tuned port? I thought if it had a dry TB, runners, and 1 injector/cylinder, then it was TPI?
TPI is just a standard small block chevy w/ a Multi-Port Injection system that Chevy called "Tuned Port Injection", it's just a trade name, kind of like early vettes "Cross Fire injection". TPI moors have long tuned runners, probably hence the name TPI. LT1 motor's are a completely different motor. Different engine blocks, reverse flow heads, gear drive water pump, distributor on the front of the motor. It was the first redesign of the small block and bosted higher output and many improvements over the (at the time) 30+ year old small block. Just as the LS1 is to the LT1, the LT1 is to the small block.
Fred could chime in and tell you more.
close, but no. TPI is batch fire which means when one cylinder fires, that whole bank of injectors on that side of the motor fires. So it's basically firing all the injectors on that side of the motor to fuel one cylinder. Little bit primative, but it works. Some systems use MAF sensors, some are speed density that rely on the MAP sensor and VSS signal.
The only year of LT1 that is TPI is a 93 LT1, they still are controlled by the TPI computer and are batch fire. From 94 to 97 the LT1s were Sequintal Port Fuel Injection which fires one injector for each injector instead of firing a whole side of the motor to fuel one cylinder. Much better tunability and efficiency. LT1s also are neither speed density nor MAF systems alone. They are kind of a hybrid system that uses both a MAF and a MAP along with the VSS to keep everything in check. Big bonus for cammed/big head motors.
Also, TPI motors use a standard small cap HEI ignition system to power it while an LT1 uses a dual pickup system that senses 8 points of contact and also 360* of rotation to power a single coil system that controls timing advance and knock retard extremely accurately.
If you require further explaination between a TPI and SPFI LT1, just ask Doug Bedwetter, he learned all about LT1s the last time I had to explain the differences in chevy motors.
Sweet! So are we talking about the same guy (works on King Ranch)?
The blocks are still the same then, right?
Is the distributor under the TB?
Is my vortec SMPI then?
No, the blocks aren't the same. Real similar, but there are differences in the LT1 block for the distributor and water pump being ran off the timing gearset. The distributor is under the water pump. Very hidden.Quote:
Originally posted by uglyota
Sweet! So are we talking about the same guy (works on King Ranch)?
The blocks are still the same then, right?
Is the distributor under the TB?
Is my vortec SMPI then?
Your vortec is SPFI. The difference there is the injectors are centrally located in a pod with lines running out to the runners of the manifold.
Sounds like a pain...so it's driven directly by the crank?Quote:
Originally posted by Fredo
The distributor is under the water pump. Very hidden.
it's not too big of a pain because there are no adjustments on it. The years that were a pain were the 93-94's with the ventless optisparks that drew in moisture and usually always died when the water pump leaked on them. The 95-97's had the vented opti which is much much better about staying dry and clean.
Yeah this is Jon Cox's scout, he is the one that was the guide out at the King Ranch. He is currently between jobs. He was in town last night, but left today. I can't wait til he gets it sprung over, it will be hella sweet then. I want to see what it would run out at nastysota, I bet it could take butler's old camaro :)
hey jimmy what transmission and tcase did he use?
Dana 300 and 700R4. It all came as a package deal from ebay. He got a fairly good deal when you price out some of the stuff that's on the combo such as the adapter between the T-Case and the 700R4 from AA. 600 bones for that thing by itself.
bump
welcome to the boards John!
Though I'd shed some more light on the subject. I did this in word and pasted it. i got a little carried away, but it shouldn't leave any questions. If so feel free to ask them. This consists of some original text and some copied, but its been on my computer for so long i dont know from whence it came.
Although the LT1 shared many common dimensions, looked much the same and even had a few common parts, it was totally redesigned to provide more power with lower emissions and better fuel economy. Basically, the rotating assembly is pretty much the same and the cam can be used in any roller sbc as long as the dist drive pin doesn’t rub the timing cover. If it does it can easily be ground shorter.
Compared to the 1991 Chevy 350 L98 with TPI which is batch fire as Fred said, the LT1 made 20% more horsepower, got better fuel mileage, and had a much broader torque band with 90% of it’s peak torque available from just over 1,000 rpm all the way up to nearly 6,000 rpm. GM accomplished this by reverse cooling the engine (meaning the coolant directly from the radiator enters the heads before the block) so they could bump the compression ratio up to 10.5 to 1, tweaking the airflow in and out of the engine with a new intake and d-port exhaust runners, and using sophisticated electronic controls for both fuel and ignition. TPI fires two shots per cylinder per revolution. Rather than an injector firing twice per revolution and the half fuel waiting in the intake runner for the intake stroke, the injection is sequential and the corresponding injector only fires on the cylinders intake stroke.
GM had some problems with the early distributor due to both carbon tracking and moisture, so a new sealed distributor with a vacuum port was introduced in 1994 and used on all LT1s in 1995. The distributor is evacuated to the manifold, and stayed dry rather than collecting condensation inside. The new distributor was still located on the front of the engine, but used a pilot shaft in the cam and was driven by a pin on the front face of the camshaft. This pin was simply an extended version of the pin used to orient the cam timing gear on all other small blocks.
The pilot shaft for the distributor extends through the hole in the cam gear and seats in the hole in the cam; the distributor is driven by the long dowel pin that sticks up through the cam gear. In order for me to use the zz4 cam in my LT1, I’ll have to bore the hole out larger and install the longer dowel pin.
The high-resolution encoding is done with a 360-tooth trigger wheel spinning at camshaft speed. An optical sensor (hence the name OPTI-Spark) reads these spinning teeth, and creates a simple 0 or 5 volt signal, depending on whether an opening in the teeth is or is not present. As the trigger wheel spins with the engine, this 0 or 5 volt signal becomes a square wave voltage signal. This signal is then sent to the engine management computer to determine engine speed. On the FSAE racecar, we used a 14 tooth cam gear and a separate crank sensor (don’t recall how many teeth) to establish timing. We spun that engine to 14,000 rpms if this is any indication of how accurate the timing is on the LT1.
Once the computer knows the speed of the engine, it needs to calculate the engine position in order to establish spark timing. To accomplish this task, the low-resolution engine position encoder disk is utilized. The low-resolution sensor itself is essentially identical to the high-resolution sensor. However, the low-resolution encoder disk only contains 8 teeth. Four of the teeth are of the same size, and occur at 90-degree reference intervals (these four teeth help to give quick synchronization during start-up cranking). The other four teeth have varying tooth widths. From these variable-sized teeth, the computer uses a fairly simple algorithm to determine engine position. The ‘96-97 LT1’s had a separate crank sensor. I’m not sure if this eliminated the need for the low-res sensor in the opti. The only difference I’ve ever heard about in the opti is vented (95-97) or non-vented(92-94). Fred may be able to shed some light on this for me.
The data created by the high- and low-resolution sensing system is ultimately used by the engine computer to generate one thing: ignition timing. The timing signal is sent from the computer to the ignition module, which is located next to the coil on LT1 and L99 engines. The ignition module then sends a high current “charge” signal directly to the ignition coil. Once the ignition coil is charged, it fires a high voltage electrical charge to the Opti-Spark distributor cap. The rotor inside the Opti-Spark distributor then distributes the spark to the appropriate cylinder via the distributor cap.
The water pump is driven via the cam timing chain gear. The gear consists of a chain sprocket and a toothed gear in one unit. The water pump driveshaft is driven from the gear on the back of the timing gear and extends over the cam timing gear, through the timing cover and engages the water pump from the rear.
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stay tuned folks, the rest is yet to come, it incudes:
SOA w/ RS, cross-over steering, lockers, zz4 cam which should put the LT1 to some where in the neighborhood of 350+ hp 400lb-ft, power disc brakes, kustom swing out tire carrier, and a/c
holy ****! It's like you hooked up a serial port to Fred's brain, like Matrix or some ****, weird...
Maybe at the crank...but my LT4 hotcam with 1.6 roller rockers and chromoly pushrods only brought 330hp and 345ft.lbs to the rear wheels. That is with headers, exhaust, air intake, electric water pump, and upgraded ignition. Also, it only had to travel through a 6spd and a 10 bolt. Unlike yours that will be traveling through an Auto trans, transfer case, and bigger rear axle. I would say you're looking at about 310-320 hp and 320-330 torque. Still plenty, but it's not going to be as high as you think.Quote:
Originally posted by agjohn02
zz4 cam which should put the LT1 to some where in the neighborhood of 350+ hp 400lb-ft, power disc brakes, kustom swing out tire carrier, and a/c
i just put that in there just for you fredo, to see what you would say. i may be new to posting, but ive been cruising the forum long enough to know you'd spot that and point it out... mr. im-a-nice-guy-in-person-but-i-never-have-anything-positive-to-say-on-this-forum.
anyways, i kind of agree with you, they do sound like optimistic numbers, but check out this site, this is where i got the idea to put it in there. keep in mind the one with the hotcam has the lt4 heads ad well. and, yes, i was referring to crankshaft numbers.
http://www.goautocenter.com/gen_ii_lt1.htm
i kinda split the difference between a zz4 crate motor and this info. maybe i was a little high on the torque but im guessing the hp is pretty close.
380hp 396 lb-ft, thats what you are putting out at the crank if you account for a 15% loss in a manual transmission drivetrain. the hot cam is .525 I/E with about 10 and 7 degree more duration respectively. the zz4 is .474 .510 I/E with less duration. in an unported head, duration isnt necessarily a good thing, it can result in a decrease in dynamic compression ratio. personally i think the zz4 will have higher DC than the hot. that websites spread on hp and torque is 50 and 10, but with different heads. so, to end the discussion at this ill knock off 20 each and say im gonna make 330 hp and 380 lb-ft. ill let ya know what it makes when ed wright in tulsa gets done with it.
This could get interesting! :DQuote:
Originally posted by agjohn02
i just put that in there just for you fredo, to see what you would say. i may be new to posting, but ive been cruising the forum long enough to know you'd spot that and point it out... mr. im-a-nice-guy-in-person-but-i-never-have-anything-positive-to-say-on-this-forum.
What about my previous post was mean?
Also, with the LT4 heads and Intake, you should see quite a bit more power than just the cam. I didn't realize you were talking about doing that with the cam.
no not mean, just not positive. and, no i dont think this will get too interesting, at least between fred and i. we're cool, i was just kidding around with him. do you know anything about what the crank sensor does on the later lt1's, fred? ive got some pics of the drivetrain out and should be getting my cam today. so, ill update when i get home from work.
no, im staying stock with the heads and intake. from what i gather on the goautocenter.com site, the zz4 motor has stock heads. i wish i had the lt4 stuff though. those things flow 240 cfm compared to the 195 cfm of the lt1 head. i do, however, have a red powdercoated intake manifold that looks like an lt4, thats good for at least 20 hp, surely.
If you're reffering to the crank sensor in the bottom of the timing cover on 96-97 LT1's, it is part of the OBDII diagnostics for detecting misfires. It's also a secondary reference point for telling if the OptiSpark is dying or not.
cam came in today. so, now ive got all my parts. im about to go work on the insulation now.
by the way, just wanted to recommend hedman hedders. i called them to see if they had any headers for an LT1 in a 73 Scout (yeah right), but to my surprise they were super helpful. the guy i first talked to, david ext # 203, was as helpful as he could be and never tried to rush me off the phone like most of the tech guys you talk to do. he referred me to one of their senior application guys, jim wical, and this guy wanted pictures of my engine bay to study and called me three days later with some suggestions. said he had a couple engineers look at it too. i was way impressed with their customer support.
I already have enough red X's, thanks though! :flipoff2:Quote:
Originally posted by agjohn02
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everybody needs one of these:
http://us.f1.yahoofs.com/users/4088b...e7BoABGZ0Gvvdw
yeah, red x's are a dime a dozen. .
ok, pics work then they dont, work, then they dont
am i doing something wrong or what?
just upload them to our server...one pic per post....you could have done three posts....
drivetrain in dangle mode:
MILLER TIME BABY!!!
Hmm, lots of good jeep parts.....
...... wasted on a scout. :flipoff2:
hmm, eight, is that name indicative of your desire for more inches or cylinders?
got the firewall insulation cut to fit today. havent glued it down yet though. now i gotta do the tranny tunnel to finish it out. im thinking about putting a snorkel on the scout. i havent seen one made specifically for scouts and there probably is no such thing, but im pretty sure i can find one that will work. i do not plan on doing much high water crossing, only if absolutely neccesary, i just want cold air intake. im planning out a cowl induction system for the scout that would draw air from the cowl vent, but i think a snorkel would be easier. it would be very tomb raiderish. over kill?
ok, only two weeks later and i finally got time to finish up the insulation. cross your fingers and hope it all stays stuck. next, on to the dana 300 rebuild. i got my rebuild kit from advance adapters this week and can finally get started on it. anyone rebuilt one before? do you need a press to get bearings and such off and on? or will a deadblow hammer and a couple 2x4's suffice?
The hammer and 2x4 method should work. I use oak. A few sizes of chisel and some sizes of plate can also be helpful.
And eight is just because that's what my jeep is. I need not more inches or cylinders.
got the t-case apart with the exception of the rear output shaft. ill have to get it pressed out as i havent a press or funky log jawed gear puller. the hammer and 2x4 method worked quite well. i found white pine to meet my needs. however you do need a couple sizes of gear puller for a couple bearings. you can see them in the pic.
here's the culprit. big gear wont come off until bearing is off and big gear wont fit throught hole in case. this is like the mother of all jigsaw puzzles. guess it'll have to wait till next week, cuz i aint got time to get it done on tuesday and ill be outta town the rest of the week for an interview. also, i need 1310 cv yokes for this case front and rear. will atlas yokes work? 29 spline i think but i cant remember for sure. or does anybody know a better place to get em?
more parts and little progress to post. if you wanna see my progress, go to the dana 300 output shaft wanted post. that about sums up my progress, i had to take breather after screwing that pooch. anyways got my shocks and underhood a/c stuff from the big brown truck today. rancho rs 5012 and 5010 long travels and camaro a/c stuff for the lt1. dont really know what my next step is now. whatever i feel like working on next i guess. frame bracing under the steering box, engine gasket kit and completion of tcase rebuild are the options. i decided to forgo the cam swap for now. at least until i get some money for the ecm re-program and gas prices drop.
about a week after my last post i sprained the crap outta my right ankle and have been crippled ever since. ive gotten some work done though. frame is braced under the steering box, sprayed the frame with rubber undercoating except where i have to weld stuff. got the t-case rebuilt with the exception of yokes and endplay settings. got the power booster, painted it and put that stuff together. looking for a new inner fender, mine was held together by rust.
just a little more detail on how i re-enforced the frame under the steering box. 3/16" plate inside, outside, and bottom. there wasnt enough room between the box and frame to do it on top. pics arent the clearest, but they give you the idea.