Will a set of stock springs on a aluminum L98 head run enough lift for a LT1 cam. I don't mean the HOTcam, just the stock GM cam. I don't want to go breaking things as soon as I have them on the engine. Thanks in advance.

 

Probably, but why? Springs are cheap.

 

This is true, but I was just curious.
Another question, do they have roller rockers?

 

No roller rockers ever cam stock.

 

Ok. Thanks. Do you think that a set of roller rockers or 1.6s would help enough to justify the cost?

 

I'd spend the money on a better cam.

 

I know the LT1 isn't that great of a cam. I just want a somewhat cheap intermediary. The LT1 and L98 heads are just something to get me a little more go-go with as little trouble as possible. I just wanted to know if I would have problems from the springs.

 

Uh, I just thought of this. Will the L98s bolt up to the TBI intake manifold? If not, what would be a good replacement? Heck, what would be a good replacement even if they do mate up? Stock intake on better cam and heads....

Oh, and are there any flow differences between the iron and the aluminum heads? Other than the cost and weight.

 

man seriously, the springs might take the lift, they might not. But you can have new springs delivered to your house for less then $33 delivered good for .550 lift and all. they are what the autom otive world refers to as Z28 springs. Basic but plenty enough for what you need.

go here and get these springs, i order a few sets a month from him for my customers, atleast you wont have to constantly ask yourself are my springs gonna take this. You should be asking yourself, are my pockets large enough if they cant and dont. Valve float will cause a bunch of problems and lifters aint cheap.
http://cgi.ebay.com/ebaymotors/SBC-C...temZ8026029901

 

Thanks. That is what I wanted to know. That will really hlp me with the build. I didn't want to overspend or not spend and be worried all the time or break something. I'll have to get a set when I get the heads and cam.

Anyone know about the flow or matching heads to intake?

 

like what?

intake volume and rpm range?

Intake port size compared to intake volume?



Need details, with TPI there really isn't much of a way to compare it to any head flow rates simply becuase the runners are uncapable of flowing the numbers a head can. A set of AFR 195's would flow so much better with a better intake, in that equasion the tpi is the bottleneck.

I personally went from TPI to carb when i did my motor swap. It isn't as hard as its cracked up to be. Fuel pressure regulator and intake/carb/distributor is all thats needed really. I'd recomend carb swaps for any performance application, many on the boards go the other way from carb to tpi, but Fuel injection has too many components to just wait to break and they always do. Plus tuning is so expensive it drags out cost 10 fold.

 

Right now my engine is TBI. I am just trying to get some more go-go from it. I was wondering if there was a flow difference between the iron and aluminim heads and if the TBI intake would bolt on to the L98 (TPI) heads. I think that with the L98 heads, I might need a better intake than the stock TBI one.

 

Iron l98 heads have adecent flow, but the aluminum ones are said to have about 15-20cfm more in the exhaust port.

Depending on the year of your TBI intake it should bolt to the heads. If not, you can always modify bolt patter of those particular bolts to fit.

Stock TBI intake is supposedly fine. I've never heard many complaints. If you get a 1" spacer i've heard it can increase power greatly.

 

My TBI is a factory 91. I am getting the 1 TB spacer and a 1/4 inch injector spacer to get more air into the top of it. I think that I will go aluminum. The extra CFM will make more room for new things to go BOOM. Thing is, the irons I've seen as cheap as $150+ shipping. Aluminums are more like $400 and up. I don't know if the power gains will make up the difference in the price.

 

i aquired my old l98 heads for $50. I ported and polished them, made a very decent amount of power and ran a solid 12.2 1/4 mile time. With much room for traction.

Try local adds before you try to find them on the net. I was lucky because mine had actually never been used. casting number 083 is "l98" heads, and they also came out of many crate motors. A guy i know got a crate motor back in the day with those heads sitting on them. Took them off and installed a set of Dart's and called it a day. The 083's sat for 3 or 4 years before i aquired them.

Try your local junkyardsa as well. Dont call and ask if they have any either, go and look for yourself. Junkyard phone operators dont know crap.

 

I thought about lookin, but it pretty COLD around here now. LOL
I will check around. I know a guy that has a set with an LT1 cam for $450 + shipping.
I know where a 91 TPI Vette is now. Don't know what the plans are for it, but I can see. I want to have this to be reliable, but as cheap as possilbe. My real goals involve a build LS6.
Thanks for all the advice and info. I really hope I can find a good set of heads local.

 

never trust used heads from a distance. If someone ships you a set of heads that "ran" in the preivous car, they could easily be cracked, and a whole bunch of existing problems.

a good saying to go by in life is this,

"if the enemy is judged solely by his appearance, he is sure to succeed."

meaning a person seeming to be nice over the net, could be the biggest thief in real life sending you a set of heads he knows and junk.

 

Just an FYI, it's not the springs themselves that are the impediment of factory lift limits - it's the amount of clearance between the bottom of the retainer and the guide boss. About .480" before things start to get dangerous.

But yes, springs are cheap - replace them, get rid of the stupid factory hardware like the exhaust rotators while you're at it.

 

As said, the springs won't be the problem. Skip the roller rockers, get better heads as you are planning and get a better cam than the LT1. The cost of getting roller rockers and the LT1 cam, just get a better cam and stick with the stock rockers, it's cheaper. Stock heads can't handle much lift anyway. Save the roller rockers for a different setup.

 

As have already said, this is my intermediary engine. I am going for inexpensive and fast. With the L98s, they will bolt right on and I don't have to worry about compression. The LT1 cam is old and pretty common, so getting a mail order tune from PCMforless will be easy and pretty acurate. I'm not going with the 1.6 rockers, just new springs. I want to get the car a litlle faster than its current 16.5s at Bristol Dragway. My end plans involve a LS1 based engine with aftermarket heads and cam.

And what is exhaust rotators, by the way?

 

Heh...that's funny because it's contrarian.

You'll probably want this link.

https://www.thirdgen.org/techbb2/sho...hreadid=262466

Since you're buying a chip that cost is the same, irregardless of your cam, FWIW. There are many old cams out there with plenty of data.

I didn't see where you *weren't* getting 1.6 rockers since you asked about 1.6 rockers and porting and a bunch of other stuff that has nothing to do with springs.

Big stuff on your valve springs. You'll see them when you pop the valve covers. You can't miss it.

 

Aluminum L-98 heads won't take a TBI intake. The aluminum heads use the old 85-down intake bolt pattern where your TBI intake uses the 87-up pattern with the 2 center bolts "stood up" at a different angle. You might be able to modify the intake manifold to work with the older bolt pattern but it won't bolt right on.

Also, those heads don't have an exhaust cross-over port which means your EGR system will not fuction. Will require turning it off inside the chip programming to prevent throwing an EGR code.

LT-1 cam with 1.5 rocker arms should be no problem as far as lift goes. With 1.6s...... don't know. Might be marginal. Agreed, around .470 lift is where you start to run into problems.

 

I didn't mean the car being fast. I mean the swap being fast.

As for buying the chip, I know the cost will be the same. That is why I said pretty accurate. Common cams are easier to tune for, or at least that is what I have read.

I guess I forgot to say that I wasn't getting the 1.6 rockers. Sorry, I thought I did.

Could I get an aftermarket intake (for TBI or carb) that would bolt up without modifications other than a TB adapter plate or something of the like?

 

You're going away from inexpensive real fast.

Just slot the holes, this is temporary right?

If you wanted to stay cheap, get the 083 heads instead of the aluminum 113 castings.

 

How do the 083s flow compared to the 113s?

 

A bit less, mostly on the exhaust side. Do a search on it. The stock flow rates are on the forum, posted multiple times throughout it's existence. The big thing is that it's a ton cheaper than the 113 castings.

If you're good with your hands and have time, you can port the hell out of them too. Do a search on 083 heads and rhuarc I think. That'll give you a general idea of how much you can gain. Most people, myself included, would not be able to achieve that.

 

From what I am reading, the 083s have a 64cc combustio chamber. I need something with 58cc, like my swirl ports. Do the 133s have 58cc? I was thinking that they did. From what I have seen, they do. Thanks.

N/m. I just found this thread. It says the 083s have 64cc and the 113s have 58cc. What would have to be done (other than new pistons) to get the compression ration back up near the stock 9.3:1?

 

Oh 305? Go for the 081 heads then, stock 305 TPI heads. 083 are stock 350 TPI heads. 58cc aluminum will actually be less than 58cc iron in terms of performance. You need to bump compression up about 0.5 to make up for the aluminum heat exchange. The 58cc aluminum is made for the 350s with , the corresponding 350 iron heads which are 64cc on the TPIs.

Man, your handle and actual config is throwing me for a loop.

You should go post in the TBI section...

 

Lol. Sorry. When I signed up I was looking to sell my RS and get a red 91 TPI350 car. Never changed it.
I hadn't thought about the heat exchange. I knrew that aluminum heads could run higher compression than irons, but hadn't thought about problems in going aluminum with the same compression. I'd need to get pistons to run the 133s, and that is running from cheap fast. But, I might have to rebuild the engine soon, so the 133s with new pistons would be nice. IDK. Thanks for warning me, though. I would have been pissed to make a big booboo like that.