i am buildin a 363 (4.06x3.5)sb with ported zz4 heads, lt1 intake and about 10.5:1 compression. i am considering this cam, a solid roller from lunati. the car is going to be moslty race, but occasionally street driven

Advertised Duration IN/EX: 282/290
Duration @.050 IN/EX: 224/232
Gross Valve Lift IN/EX: .502"/.502"
Lobe Sep Angle / Intake Ctr Line: 112/108
Valve Lash IN/EX: .022"/.024"
RPM Range: 2800-6600

 

If you want the car to be mostly race, i would go with higher flowing heads. Instead of the ZZ4, go with the Fast Burn Heads, and then try the LT4 hotcam with 1.6 rockers, with that combo, you should see about 425 horse, with the appropriate intake. Solid lifters are not necessary with that amount of lift.

 

That cam you have would be great for a set of FastBurn heads or something along those lines. That cam should make a bit more power than an LT4 hotcam, albeit a couple hundered RPM higher. Though since its going to be mostly drag, having a higher power band shouldn't hurt anything.

With the heads you have though, I'd say to go with the LT4 Hot Cam, since it has a bit more of a split-pattern design.

 

i plan on upgrading the heads as soon as i can get money for them. i also wanted to try having the external coolant lines exit from the heads instead of rigging them trough the intake. this way i dont ruin an expensive set of heads if it does not work.
thanks for the input

 

By modifying the heads, you'd be possibly ruining a good set of heads if it doesn't work. There is no risk invovled if you stick with the tried and true through-the-intake setup since that's how all standard SBC intakes are set up. If you modify the heads to exit coolant from them and then you end up not using the LT1 intake, you have to buy new heads because your modified ones won't work with a standard intake.

 

Just for ideas here are my modded LT1 heads to work on a SBC with an SBC intake.

 

Another

 

Looks nice, I fired my 355 with LT1 heads/intake up today for the first time. I'd probably be driving it right now if it wasn't for the fuel hose that I found leaking. I'm going to email John Millican in a few minutes and see if he can do anything for me since that was one of the hoses he made.

 

Last one

 

I'm gonna be driving my sucker sunday, as soon as i swap in my new summit th350 tranny and put on a new PS pump..

Hopefully its nuts, its should be a fun ride atleast!

 

the main reason i am planning on routing the hoses through the heads is to clean up the installation, also there is more material in the heads for sealing (im kinda paraniod about leaks).

meleigh, waht size fittings are you using? your engine looks good!

 

How are you going to get the air out of it and keep it out? Or do you figure it'll just pump up on start up? Also, I'd be concerned with one collapasing on decell...

Did you think of hardlines, bent to fit...maybe with a bleeder valve at the high point?

I dunno, maybe you have it all worked out, I'm just curious.

 

LT1 motors don't have coolant running through the intake from the factory, so you just tap into the coolant paths in the head. On a standard SBC, to do that, you'd have to weld and mill the intake mating surface on the heads to block off the coolant ports and then drill to get water outlets. Cleaner? A stock SBC intake would look cleaner with only one hose coming out of the intake instead of a hose from each head.

In fact, now that I think about it, I'm not quite sure why Leigh didn't just use a remote t-stat to eliminate coolant from going through the intake at all. Make the intake a dry setup like my LT1 intake.

 

The fittings are 1/2" NPT to 3/4 hose barb.

I blocked off the water ports on the intake and used it as a manifold for the four hoses. I figured why no just do it easily and run the thermostat in the stock location.

Originally i was planning to make a remote t-stat setup, but thought better off it. It would have been kinda hard to make on and i'm a cheap bastard. I hate to pay for stuff i can do my self.

As for bleeding air from the hoses i don't really think that its that big of a problem. Its really just kinda like a heater hose setup.

I will let you guys know how the whole setup works after i put in my new tranny that i blewup.

 

air in the lines should not be an issue, even if it is, you could bleed it by taking the hoses loose. as soon as i can get some pics of my installation , ill post them. i made a hole in the stock acc. bracket under the alt on driver side, and since i am not running a/c i have plenty of room on the other side with no mods to the bracket. the lt1 intake will be installed without having to plumb it with fittings ( maybe a bleeder). if i decide to go with another intake, i can simply plug the holes in the heads. ill let yall know haw it all turns out, but it wont be until after tax time( refund $$$)

 

Huh, any details on making the LT1 heads work on an SBC (has there been a thread here, I haven’t seen it but I don’t drop into general engine tech often)?

From the pics it looks like you’re basically just connecting to the end water passages like SBC heads are cast. Are any other changes made to the heads? Are the deck surfaces the same or does something need to be changed there?

Is there a reason why you’re drilling and tapping fittings in the end of the head instead of drilling in the stock SBC water crossover locations? Accessory holes?

 

Yes since LT1 heads are reverse cooled the coolant ports on the deck surface are similar but measurably different than SBC heads. Specifically there is a water passage that needs to be welded up.

I choose to go the simpelest route on plumbing the water out of the heads. Instead of boring a hole in the heads and welding in a sleeve or tube to plumb water into the intake like a normal sbc. I chose to just drill, tap and run external lines, instead of blocking the oil drain-back holes in the LT1 heads to internally plumb water to the intake and thermostat.

You can do a and find the 3 page thread on this in the TPI section.

 

Yea, I found that thread last night.

Thanks for the pic. That actually helped quite a bit.

Since if I was going to do it I’d do it with iron heads, I’m not sure how much I’d trust the whole welding thing… I’d probably seriously consider epoxying the plugs in and then in the long run just braze something in there. Does that surface there have to actually be flat for any reason or can it be recessed?

Looks like running the coolant through the stock coolant crossover locations would take a little creativity, but nothing impossible… Huh, interesting, but I’m not sure that in my case it might not just be easier to rebuild the LT1 and use it… eventually instead of scavenging parts from it.

 

i do believe it could be recessed. if you put the plugs in with some good sealer, like locktite, you sould not need to braze them in. you could press in a plug, use locktite to seal it, and get it machined flat if it sticks out.

 

Or just find a good race shop that repairs cylinder heads and have them weld them shut. I paid $160 to weld the 4 sections closed and mill the heads flat. Paid another $20 to drill and tap the two holes in front, and another $35 to get a cylinder flowed/CC'd. Not bad for $215

52cc heads, flow 221/185

 

Nice flow #'s are those stock LT1 #'s?

 

I did a bit of touching up to them. I did quite a bit on the exhaust ports and then half-assedly polished them. They flow better than stock LT4s on the exhaust side. On the intake side I really just removed casting flaws and smoothed out where the valve seats meet the bowl. Tried to grind down all the aluminum around the valve guides but it was a bit hard using a round file and an electric drill Stock valves too.

I'll eventually get them ported to LE2 by Lloyd Eliott.

 

I just have one question for Bowtienick. Why are you going to go to all the work of converting ZZ4 heads to work with a LT1 intake when it would be cheaper and simpler to run an Edelbrock RPM AirGap intake?

 

i am running efi, using lt1 intake with gen 1 sb. you may have me confused with meleigh, who is using lt1 heads on a gen 1 block with a carbureted intake. that is his engine in the pics. i need to get a digital cam and ill post my pics .

 

Let me try this again because I don't think I made what I was trying to say clear. You have a complete ZZ4 crate motor if I'm not mistaken. My question was why not go the carb route. You said you wanted to stick with fuel injection. Now my question is, why accept the lower flowing LT1 heads instead of the higher flowing Vortech's? If it's your desire to run fuel injection, then why not just get an Edelbrock Pro-Flo fuel injection set up instead of doing all this work to use LT1 heads and intake with fuel injection? I realize that it will cost just as much, but you will get a better all around system in my opinion with some tuneability. If it's too pricey then check out F.A.S.T. or Accel's Commander systems. Like I said, I'm just curious, not trying to be a jerk.

 

the heads are what i have now, ill upgrade after i get the rest of the car built. the lt1 intake allows me to use most stock components after it is modified. all together the intake, and an aftermarket controller are putting me out maybe a grand. part of it is curiosity to see how this combo will work, also. race cars are never finished, and this is not going to be the last combo.
also check out lt1 intake.com

 

Okay. I think I finally understand. You want to tinker around a bit. That's cool. I was just curious as to why you were taking that route.