Jump to content
HybridZ

Recommended Posts

the LT1 uses REVERSE coolant flow, if you look closely youll notice the intake and heads on an LT1 DON,T have provisions for a t-stat and radiator hose connection, on an LT1 those are located on the water pump

while the heads swap either way, the engine can,t be made to run without extensive and fairly expensive mods.

aftermarket performance heads that fit an LT1/LT4 don,t generally give any real advantage and cost a good deal more than those aftermarket performance heads for the standard gen 1 block

youll also notice the distributor on the standard engine is missing, replaced by an opti-crap ignition driven by the timing cover/cam assembly on the LT1

theres nothing wrong with an LT1 that prevents you from getting good hp, but the sellection of parts is limited and sticking with MPFI in the LT1/LT4 vs swaping to a carb is USUALLY the best route, with the least problems

 

engine4.jpg

 

the only advantage I see is the basic engine config is lower in over all height (more hood clearance)and can be seated back slightly further in the frame/firewall clearance, and with LT4 heads and intake its got good hp potential compared to most STOCK 350s with STOCK heads, and its a factory roller cam equiped engine

 

http://www.malcams.com/legacy/misc/headflow.htm

Link to post
Share on other sites

Can you comment on the efficiency of the intake/fuel injection/fuel injectors (I guess assuming you're using LT4 components???)? Are they good for a bit of power gain and is the intake free flowing? Or do you find yourself needing bigger fuel injectors and stuck with a low-flow intake once you decide to go bigger. It sounds like you're saying that a cam is really the only upgrade for these engines so I would ASSume stock induction would be sufficient.

Link to post
Share on other sites

the LT1 intake and heads are better than average stock sbc heads and intake BUT the LT4 components are noticable better still (compare)

http://www.malcams.com/legacy/misc/headflow.htm

 

the heads, intake and compression ratio on the LT4 are differant as well as other changes

 

http://www.fierolt1.com/lt1_vs_lt4_2.htm

 

http://www.corvetteactioncenter.com/specs/c4/1996/lt1lt4.html

 

BOTH engines can benefit from port work, a new cam with more durration and a higher stall converter (autos) and a rear gear ratio in the 3.73:1-4.11:1 range

Link to post
Share on other sites

just buy a Gen III/IV motor... you can have a truck 6.0 or 5.3 motor complete for $1000... if you dont want fuel injection you can do a carbed conversion also. swapping in one of the later model motors isnt anymore difficult than doing a gen 1 or 2 motor.. but the newer motors are so much more of a motor. 6 bolt mains, stock heads that flow more than almost all after market SBC heads... etc. and you can use all the older auto transmissions with it also.

Link to post
Share on other sites
Well at least don't mislead him into thinking older transmission will just bolt up. And why would you go to the trouble of using an older transmission?

 

uhhh.. it does just bolt up. you use whatever stall you want with a TH350/400 and then you have a TCI flexplate that goes on the motor..

Link to post
Share on other sites
I figured since you couldn't use an LSx T56 on a traditional sbc (right?) the autos were the same but I didn't know the bolt pattern was the same. I apologize! :cry:

 

If it's that easy and if you were making a lot of power I could see why you would want a th350/400.

 

it is correct that you cant use the LS1 T56 with the older sbcs... but its not because of the bolt pattern. the input shafts are different. i have a friend that had a TH350 in his LS1 car. you just have to get a the TCI flexplate which has provisions for either stall converter pattern

Link to post
Share on other sites
just buy a Gen III/IV motor... you can have a truck 6.0 or 5.3 motor complete for $1000... if you dont want fuel injection you can do a carbed conversion also. swapping in one of the later model motors isnt anymore difficult than doing a gen 1 or 2 motor.. but the newer motors are so much more of a motor. 6 bolt mains, stock heads that flow more than almost all after market SBC heads... etc. and you can use all the older auto transmissions with it also.

 

Please do tell where someone could get these motors for that price. I would gladly swap out my 406 for a newer motor. I can alway put the 406 back in when I am ready to put the car back on the track. Anyways...point me in the right direction of where I can buy those motors at that price COMPLETE.

Link to post
Share on other sites

The bolt pattern isn't identical. There it one missing bolt boss in the block around I think the 1 o'clock position. But, yeah, I am using a traditional SBC bellhousing to bolt the TKO to my LS2 motor.

 

LS1 240Z is talking about getting a complete truck motor for a grand. That is probably reasonable.

 

What he constantly fails to mention is the thousands of dollars of changes that need to be made to the truck motor to get them to work in a Z car. Especially if you want a manual transmission. There is a member currently putting a 5.3 in his Z. Find his recent thread to get a taste for the changes needed to make one fit.

Link to post
Share on other sites
The bolt pattern isn't identical. There it one missing bolt boss in the block around I think the 1 o'clock position. But, yeah, I am using a traditional SBC bellhousing to bolt the TKO to my LS2 motor.

 

LS1 240Z is talking about getting a complete truck motor for a grand. That is probably reasonable.

 

What he constantly fails to mention is the thousands of dollars of changes that need to be made to the truck motor to get them to work in a Z car. Especially if you want a manual transmission. There is a member currently putting a 5.3 in his Z. Find his recent thread to get a taste for the changes needed to make one fit.

 

Well if someone wanted to run an auto, those engines are not that bad of a deal. Would handle boost VERY well too. I forget, which liter sizes are the truck motors?

Link to post
Share on other sites

You can get alot of the advantage of an LT1 in your earlygen sbc by using the 5.7L vortec heads. These were placed on trucks that used the 350 `96+. You'll need vortec style intake with it though, your old manifold won't mate up.

 

These heads have the swirel inducing combustion chamber and the re-positioned sparkplug like the LT1 heads. They don't however allow for that nifty reverse coolant :-(.

 

As far as roller cams, the sbc 350 had those as well in 87+ blocks(atleast the non-truck ones, I'm not sure about truck blocks).

 

Anyone know if any sbc heads came with roller rockers? Or are these strictly aftermarket?(hope I didn't just jack the thread here).

 

I'm sure you guessed, I'm not a chevy engine expert :wink: Just some silly Z owner thats been trying to pick an expensive engine combination. So don't buy on my words, back it with your own research before droping any major $$'s

 

rx

Link to post
Share on other sites

Well the vortec engines had roller cams. If you can get your hands on one they are an excellent start on some mild power. I got one for $350 that I don't even think needed bearings but it had the FI intake on it and just need(ed) wiring harness and computer. Whenever I get around to it I've got megasquirt and a harness and a mild cam for it. The lift restriction of stock vortec heads should be mentioned. Anything above .450-.470 at the valve will cause something to not have enough clearance (I can't remember). This can be fixed with some machine work.

Link to post
Share on other sites

Are all the sbc blocks with roller cams belonging to Vortec heads? IE. all of the 90-95 pn# ch350r2 at this local rebuilder's page http://www.ledfordperformance.org/rebuilt_chevy_engines.html

 

I know the trucks didn't get Vortec heads until 96, but maybe these corvettes and such between 90 and 95 did? Or am I misunderastanding the meaning of the "1PC-SL-RLR-2 BOLT"? It should be 1 piece rear seal, roller cams, 2 bolt mains I believe.

Link to post
Share on other sites
That makes sense but I would email him for sure. You know you can buy the roller lifters and spider tray and stuff off of ebay and even gm performance parts I believe that is if you have a late model block that does not already have a roller cam.

 

I've heard of these high-dollar aftermarket retrokits for fitting a roller cam to the older engines. And I've heard of using some non-SBC GM factory parts for retrofitting as well, using lifters from a V6 and such. I think both of these methods are used for older blocks. I'm not quite sure what you mean though. Are you talking about a direct piece-by-piece swap in from 87+ roller equipped block to 87+ non-roller cam?

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...