It's not ,... but I would like to hear what makes you feel it is.

 

Didn't see the small word "adapt" in there. I shall go over to the corner and stick my foot in my mouth now Sorry kids.

 

id like to know whats envolved in getting 15* heads to fit an LT1 block! i realize the intake is gonna take some "southern engineering" in order to work but what about headers and more importantly valvetrain geometery? i dont need any detailed descriptions of all the bs evolved... just a basic list of "parts that needed ajustment" will do just fine

 

For those of you who may not beleive try this..


I crank out 400RWHP with a set of Heads Lloyd ported. Stock short block and shifting at 7,000. peak for me was at 6,800

Only two other guys I know who can do that and one posted in this thread

The Port work was $400 plus parts when I had mine done.

 

Aye, but ellis.. I remember lloyd telling me he fixed yours for free... and then you had Dave at Flow Technics pick them up quite a bit...

I must be mistaken

EDIT: Ahh.. on yer website, Flow Technics Ported LT1 heads 2.055 Int 1.57 Ext... I knew the big intake valve reminded me of someone, lol.

 

unfortunatly people dont understand HOW MUCH time goes into a freaking set of heads. This doesn't change the fact that it is expensive (as a sum of money).

Figure $1500 for a set of heads-
thats $200 in valves
$200 in a spring kit
that leave $1100
figure $150 for a valve job and back cutting valves, $50 for assembly-

thats leaving $900 for the work. I venture to say there is about 1 hr of port work per port so about 16 hrs ?

thats leaving about $50 h/r when you take out tools they use.

concidering you cant do it and it really is an art- i dont see where all the griping and bitching comes from

 

Okie dokie....

First off, the gentlemen who performed the conversion on these heads is our own Chuck Riddeck aka Mr. Horsepower, owner of Progressive Race Engine Development and a guy who doesn't spend much time here anymore.... unfortunately and for reasons I can understand.
The charge was part of a barter agreement. I'm good with computers and Chuck's good with engines so I did a programming favor for him and he returned the favor with a CNC port job and conversion of my GM 15* heads to work on the LT block. BTW, a 15* head is simply an 18* head with a 2* deck cut and 1* valve relocation. For all intents and purposes, the head starts out life as a GM 18* casting.

I'd imagine the conversion itself would cost ~$600 at a race shop but I'm not sure on that. If you're serious about it then all it would take is a visit to an engine builder to find out what he'd charge. Chances are, the builder hasn't done this but anyone familiar with LT1's should know enough to do the "alteration".

A little background......
The heads came of a Comp Elim. race engine of mine so they needed port filling and quite a bit of work to make a good street head. Cost for a set of heads like this is high but if you shop around you will find deals on 18* heads everywhere. Not unusual to find a set of refreshed 18* heads with Jesel shafts, beryllium seats and titanium valves for ~$2500. You do the math and decide if that's a deal or not. Then again you might just start more from scratch with something like this....
http://oval.race-cars.com/partbd/messages/2325.htm

I found that with a search in less than a minute.

As for headers, you'll need a custom set as most are 1-3/4 and don't have the right port spacing. Then again, you might be able to cut the flanges from a set of LT headers, buy a set of 18* head flanges from Headers By Ed and make the deal work with some slight pipe bending/moving. If all else fails... you'll have to go custom like I decided to. You're looking at $1k+ there....

Yes, I am still using the opti along with FAST engine management. The shift points will be right at 7100 rpm and peak power is at ~6700. I'm running a mild solid roller (~240 @.050) with a 110* LSA.

Intakes... there are a few options.
Make a carb intake work with a throttle body. Two ways... use a 4bbl throttle body or use an LS1-type throttle body and a 90* elbow.
2, have a custom built... ~$2500
3, Have an engine builder machine adaptors and end-rails for the LT4 intake.

The advantage of the 15 or 18 degree head is a few things. One, a very straight shot for the intake airflow. Two, relocated valves which put the intake further from the cylinder wall...... less shrouding in a small bore = better low lift and high lift flow. Small and very efficient combustion chambers..... even smaller in the 15* (mine are ~44 ccs), which will require a dish-type piston.

Just some scattered thoughts so I'll come back later to get the stuff I missed.

Did take the car to the track last night but it started to rain about the time we got in line for a run.
My thoughts so far... the car can run low 10's as it sits but I'm gonna need a lot of chassis tweaking to get into the 9's. Which is to say..... I don't think touching the 9's is out of the question. I just hope the T-56 is up to the task.

One other thing....
I didn't necessarily build this car to show off or be the "fastest". There are alot of guys out there with less money in their motors who'd blow my doors off.... and that's ok with me.
I built it for my own personal satisfaction and to be a daily driver. Otherwise I would have thrown a set of Monocoque wheels on, bumped the compression 3 points and would worry a little less about which stereo system I want to go with in this thing right now. I'm thinking Alpine.

-Mindgame

 

thanks for the info mindgame


btw.......i have a barely used Alpine Ai-net 12 Disc changer (model CHA-1214) that im not going to use, its sitting in my living room, with a 10ft (i think) Ai-net cable. the changer is a couple years old, but the model hasnt changed at all, and it works great last i had it hooked up. here is a link to the alpine website specs for it

i already sold the alpine head unit i had with it, so the changer doesnt do me any good.

if youre interested, pm me or email me at ballzdeep@comcast.net

 

Those are iron heads right?

 

That's some good info in the entire post. I think it had a lot of usefull info . It's good to see Lt1's getting even more serious, and doing different things.

If you lived around here, you would be a bank breaker. LOL. Here in "MTI TERRITORY", (Nothing against MTI. I have had good experiences with them.) Many of the Ls1's owners around here and the country though, would drool if they thought they could run an all motor LT1, or LT1 period for money. As "everyone knows Lt1's are slow". wink

I can just see it now , ... an Ls1 owner sets the all motor LT1 out 2 and lets you move. He promises to run you motor to motor, but he still sprays his hidden kit. His low 11 second stage 2 heads and cam car runs 10.70's at 127 plus mph with a 100 shot.... so they figure easy pickens and are snickering at the "12second" heads and cam lt1, and are already planning to buy some new MT ET STREETS and a new pair of NIKES with your money Lol. Then the flag drops and even the hidden kit ain't enough for the low 10 - high 9 second street freak. After an easy "pay day" , they hand over the cash, and as you walk off , the angriest one just can't take it, and yells out. " How about you run my dads 422 STROKER C5 for the same amount!!.................................. ...... NEXT. LOL.

(Yes , I was bored when I wrote this. lol)



When you say port filling are you talking about adding material to reduce the volume of the runners?
Because at the next rebuild I would like to convert some 18* heads, but the problem is that the smallest runners I have seen are about ~ 240 cc with 18 * heads that I have been looking at lately. It's my daily driver, so even though I know 18* , 15*, 14*.. etc heads have greater low and mid lift flow and velocity, I would still like an intake port of less than 220.

 

got hp,

Let me do some reading up on that system and I'll be getting with you. Probably this weekend when I have a bit more time. You will be hearing from me though, thanks!

Evl,

No they're aluminum castings.

Rpm,

My heads were originally 264 cc so yeah, they needed to be welded up along the port floors. Mind you, the head has to be stripped of everything when doing that, so the seats, guides, everything has to be replaced after the head is "normalized".

You're right, most of the 18* stuff out there is gonna be 245 ccs on up. Thing to do is to start with a virgin casting which will be right around 200 ccs. Then have someone hand port the head. CNC may not be in your price range but this keeps the cost down. Believe me, there are alot of guys out there who know these heads real well. They've been working with em for years now.

And yeah, I know the MTI guys have some strong LS1/LS6's. The 15/18* head swap levels the playing field there. You could take a small port head (~200-210 ccs) and a mild cam (220-224-ish) like the LS guys and make the same hp they're making if not more on the LT block.
A really good head makes all the difference in the world.

-Mindgame

 

Damn, I was under the impression that it takes around 35-40 hours to do a set of heads nicely. Not in 16 hours unless someones just butchering your stuff. Hell I could be wrong though...

 

depends on who is doing them, how much work is in it, and the port. My friend spent about 80 hrs excluding the chambers and valve job for his TT cobra

 

Shifting a stock shortblock to 7k??

 

can you give me more accurate numbers (ie 500, .520, .540, .560)

from 450- 640?

thanks