LT1 help

[prairiehotrodder]

I have a 94 buick roadmaster parts car that has the P-code LT1 5.7 engine. I believe its rated at 260 hp. I also have a 80 malibu 4 door that i am considering using to teach my wife how to bracket race and eventually my kids. I have no desire to muck with all the electronics of the LT1 engine. Do you know if the long block from the roadmaster can be dumbed down to a carb and HEI and normal water pump ? right now it is bone stock with the opti-spark and i believe reverse cooling. I'm not looking for power, just to simply drop it in and make it run. Thankyou
Brian

[FC-Pilot]

Yes and no. You can put a carb intake and rear distributor in it and run it. Chevy makes an intake (which uses the LT1 bolt holes which are a little different than standard) and it has the hole in the rear for the distributor. You can't use a normal water pump on it, but I have seen guys with LT1 specific electric pumps on them, so you could put an electric on it as it would still be reverse cooling. If you want to go crazy you can get a regular SBC intake and drill new holes to line up with the LT1 holes and weld up the rest and make it work. If you want a single plane that may be what you have to do. At that point, I would leave the opti spark there and just not use it. In fact I am planning on doing something similar. I plan on keeping mine fuel injected but put a distributor in the rear and just use the opti as a pickup and use the rear distributor like a crank trigger distributor as to keep the opti pickup sensor lasting longer.

Paul

[prairiehotrodder]

what part number is that intake ?

[cardo0]

They are not cheap intakes but all the vendors sell them: https://www.summitracing.com/parts/nal-24502592

I don't know why you can't run the LT1 WP as it's driven by the motor. The usual problem is there is no way to drive a radiator fan. I believe the mechanical fan on the B-body cars won't work - that I'm told but never tried it. Also my '94 GEN II LT1 block has no casting for a mechanical fuel pump so electric fuel pump is required. But the carburated LT1 is a favorite of budget small track racers as the heads flow very well for a sbc head. Not as well as most aftermarket heads but your talking 220cfm @28" WC with higher velocity smallish valves - meaning torquey and good throttle response. Oh and while the B-BODY cars had lower compression with iron heads they outflow the LT1 aluminum heads.

Hope this helps ya.

[grandsport51]

Thanks to LS1 Tech
This is for gen 2 LT-1
The Full Carb Swap Parts List And What It Takes
#1
suicidal racing's Avatarsuicidal racing , 04-10-2010 01:11 PM
This is to help all thoughs out who are wanting to swap over from fuel injection to Carb and for thoughs who are sick of doing the opti 5 nuckle shuffle!


PART 1..ENGINE INFO AND PARTS NEEDED

These are the main engine parts you will need to use to convert over to the carb setup

1. G.m lt1 dual plane intake or you can run some other gen 1 intake.
http://www.summitracing.com/parts/NAL-24502592/

2. G.m vented opti timeing cover because you will need to use the part below and it only fits vented covers
http://paceperformance.com/index.asp...&ProdID=130501

3. You will need this indicater so you can read your timing.
http://www.summitracing.com/parts/NAL-12367600/

Edit #2 an 3 are optional now,after more research ive found out that if you just weld up your water pump drive hole if your running a electric pump and the opti hole you then can just run a cheap gen 1 sbc timing pointer they run about 8$ at autozone.i know for sure they work on the non vented covers..this option right here will save you a nice chunk of change.heres a pic of a spectra 4237 on a motor http://i97.photobucket.com/albums/l2...8/57af2f6f.jpg

4. Now you will have to change your stock balancer to a pinned style with timing marks so you can set your timing
http://www.summitracing.com/parts/PFS-80030/

sfi aproved one
http://www.summitracing.com/parts/PFS-90030/






PART 2..IGNITION SYSTEM INFO AND PARTS NEEDED

These are the routes you can go for your ignition system,their is a couple ways so i will list them all for you guys and girls so you can choose what suits your needs best.


HEI STYLE SETUPS

1. Summit hei distributer
http://www.summitracing.com/parts/SUM-850001R/
Flame thrower module so you have better spark output in the upper rpms
http://www.summitracing.com/parts/PNX-D2000/

2. Msd hei distributer,you dont need the module posted above because it has enough spark output.
http://www.summitracing.com/parts/MSD-8362/

3. Heres the rpm module that you would need on either distr msd or summit to have a rpm rev limter or you can just buy the kit below as #4..if you get this you dont need the pertronix flame thrower one posted under the summit distributer and in all honesty if your going this route just buy the summit distributer
http://www.summitracing.com/parts/MSD-83645/

4. Here is a complete msd hei setup/kit you can use along with the summit distributer that gives you a 6al box
http://www.summitracing.com/parts/MSD-8500/


POINTS STYLE SYSTEM

1. This kit is what you can go with if you do not want to go the hei route an would like to use the older points style system for ignition
http://www.jegs.com/i/MSD+Ignition/121/6421K/10002/-1

Plug wires this is up to you for what you would like to use such as either custom kits or reg kits.You will be using gen 1 style sbc kits though now.

Final part will be a distributer hold down bracket for either route you use for ignition system
http://www.summitracing.com/parts/SUM-400500/







PART 3. FUEL SYSTEM INFO AN PARTS NEEDED

You will need to change your fuel pump maybe,I say this because some get away with there pump they already have and some dont.Im not going to list fuel pumps in here because thats up to you and i do not know your hp output.Im also not going to list fuel lines because thats up to you.

Now depending on your deal,If you use the stock pump you will be running a return style system an i recommend running your return line 1 size larger then your inlet system do to the fi style pumps being high pressure pumps.

If you swap the pump to a non high pressure style of pump you can either run whats called a dead headed system which is a system with no return line or you can run a bypass style regulator and run a return style system.You can run say a holley blue or black with the stock tank and re do all your fuel lines if you want..I then would just take my fuel pump out my stock tank,leave the stock sending unit and put a bulk head fitting into the tank..then just run a line off that into a filter and then my fuel pump after that if i wanted to use the stock tank..i would use the stock return port an do the same if i wasnt running a dead headed system..if running a dead head make sure to cap your return line port..


1. Dead headed system reg
http://www.summitracing.com/parts/HLY-12-803/

2. bypass return reg
http://www.summitracing.com/parts/AEI-13301/

theres cheaper and more costly regs you can pick from,these are 2 ive used.


3. Now if your using the stock tank and rear lines you will need hard line fitting adapters for the fuel line running forward and your return line..you could get away with using stock but its better to swap out to the size you need and upgrade to new lines i feel.
http://www.summitracing.com/search/D...eyword=adapter

4. Fuel pressure gauge so you can set your pressure.You will need an inline adapter or you can get a carb feed line kit that has a npt fitting so you can attach your gauge.
http://www.summitracing.com/parts/AEI-15632/

Link to fittings page for this
http://www.summitracing.com/search/D...=fuel+pressure

5. Carb feed lines,heres the page so you can choose the ones you need depending the carb your using
http://www.summitracing.com/search/?...Lines%20&dds=1

6. Carb,you can go alot of routes this way but heres 2 4160 carbs you can get that will work or you can get a 4150 style double pumper and such,it all will depend on your needs

Eletronic choke
http://www.summitracing.com/parts/HLY-0-80508S/
Manual choke
http://www.summitracing.com/parts/HLY-0-3310C/

7. Carb linkage an throttle brackets will depend on your carb so heres a page
http://www.summitracing.com/search/P...+cable+bracket

If you get 1 of the carbs listed above or a 4150 this will work if your running a manual valve body trans
http://www.summitracing.com/parts/HLY-20-88/



PART 4..OTHER USEFUL INFO


1. When using a 700r4 you can remove the pc completely,if you have a 4l60e you will have to swap over to a 700r4,th350 or th400 if you want to ditch the pc.the 4l60e trans uses the info from the engine from the pc for when to shift i believe.

2. If you want to keep the 4l60e and ditch the ecu you will need something along the lines of this to run the trans(thanks somlt1 for the info)
http://www.summitracing.com/parts/TCI-377500/

3. Now just run your fan off a manual switch

4. If your water pump is a electric one you can just run it on a manual switch also.

5. For the gauges you can just get manual gauges an stuff..lights,wipers and such are not run by the ecu..

6. Your fuel pump you can wire up to either come on when you turn your ignition or you can run it also off a manual switch like the fan,water pump and such.A good saftey trick is run a oil pressure kill switch inline so if your in a wreck and your knocked out and motor is off your pump dont stay on feeding a fire or spitting fuel every where.



I beleive this covers all the info to make a full swap and to give you and idea of the cost of it.If there is any suggestions,tips or other usefull info please post it up to help others out.

Thanks

#2
ADM's AvatarADM , 04-11-2010 12:09 PM
I just checked on the MSD website, it says the MSD 8362 has the 4 pin module included with it. I e-mailed them to confirm if its included or needs to be purchased separately.

Will someone make this a sticky, extremely informative write-up. Thanks suicidal racing for all the effort you put into making this thread.

EDIT: I quote from MSD's Street Fire website :-

Quote:
Inside, the ignition module and coil work together to produce a stout spark to light the fuel mixture for great performance. The high voltage is transferred through a new rotor to the brass terminals of the distributor cap and out to the plugs. The Street Fire Distributor is the first product to come from our new value branded ignition line.
#3
suicidal racing's Avatarsuicidal racing , 04-11-2010 04:46 PM
You are right adm the msd 8362 that i have for #2 on the hei list does not need a 4 pin module like i have under the #1 which is a summit hei distributer that i say to grab a flame thrower 4pin module to use in conjunction with the summit distributer..the msd already has the high output needed for the upper rpms.


Now with that being said #3 on the list is a msd 4 pin module that needs to be used with either hei distributer no matter if it the summit one or the msd one i have posted above..THE MODULE IS AN HIGH OUTPUT ONE WITH A BUILT IN REV LIMITER THAT NITHER THE SUMMIT OR MSD DISTRIBUTERS LISTED ABOVE HAVE UNLESS YOU GO WITH #4 ON THE LIST UNDER HEI.so now if you plan on geting the rev limiter module or the kit that i have as #4 i would just get the summit distributer seeing its 40$ cheaper then the msd one listed.
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#4
Black94Z28's AvatarBlack94Z28 , 07-21-2010 10:44 AM
Bookmarked this, why isnt his a sticky?
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#5
suicidal racing's Avatarsuicidal racing , 07-21-2010 01:35 PM
because carbed guys get no love..lol i dont know though on a the real level..

heres a way to wire in the fuel pressure saftety switch and electronic fuel pump an how to clean a holley fuel pump.
http://holley.com/data/Products/Tech...199R7914-3.pdf



Now lets talk trans seeing if your going to a carb your more then likely on the more hard core side and will be using a th350,th400 or glide...only the th350 will work with stock drive shafts..the 400 and glide will need custom made ones.

If you are going to run a th350 trans you will want one with a 9" tail shaft on it(these where used in 70s/80s vans and trucks)

bmr makes trans mount bracket that lets you either use the stock auto's tq arm or they make one for about 50$ cheaper that is just the trans mount with out the tq arm mount on it..If you got a after market tq arm that mounts to a cross bar then you would want that or if you had a 6spd.

Now also remember th350,400s and glides converters have 2 different bolt spacings meaning some are ment to be used on a flex plate that has 11.50 pattern or some have the other 10.75" pattern..

the stock lt1's flex plates are 153 tooth,externaly balanced 1pc rear main seal and have 10.75 pattern on them..least mine is/was(i learned this the hard way but needed a sfi plate anyways so it wasnt a big deal)

this is the plate i have now and is set up for both bolt patterns
http://www.summitracing.com/parts/QTI-RM-932/





NOW seeing your converting over and now will me running a none electonicaly controled trans an motor you will be looking at the stock wireing and going man i need to trim this up..its easier to just buy a wireing kit and rewire the whole car vs trying to go threw your harness 1 wire at a time not to mention gm was slick and some of them wires are tied into 3 or 4 different things so one bad snip and your done for..

This is the kit im using to do my car(all but my fuel level gauge is mechanical,an my windows are perm up for now)..its very simple and straight forward..you could rewire your whole car in a day really an thats the avg joe..some stuff would take longer like having all electronic gauges,getting your power windows figured out..you know.
http://www.speedwaymotors.com/Econom...ness,2352.html

heres a 20 circuit version say if you have more stuff..
http://www.speedwaymotors.com/Mr-Roa...ess,42872.html

[prairiehotrodder]

Thankyou for all the info, it pretty much helped me to decide not to bother. I also have a 94 chevy halfton with a TBI 350 that i can put in the malibu alot easier. It doesn't need to be fast. I just want my Wife to take it down the track to see if she enjoys it.
Brian