LenT1

Hi, im looking to have a 383 LT1 built for my 95TA. I found a guy that builds them often and has offered me a good price. He has listed most of the parts used in his regular stroker kit he uses but im worried about some of the parts, not sure how good they are, can you guys please give me some input on these parts and what I should have switched out, hes willing to use whatever I want really, but I need to do more research to find out whats good.

Eagle "ESP" Forged H-Beam Connecting Rods
Hastings Moly Rings
Clevite 77 Rod Bearings
Clevite 77 Main Bearings
Melling High Volume Oil Pump
Complete Fel-Pro Gasket Set
Durabond Cam Bearings
Pioneer Brass Expansion Plugs
Scat Crankshaft 3.750 Stroke 5.7" Rod
High Performance Roller Lifters.
3pc Timing Set
He will use the cam of my choice.
LT1 ported intake manifold (to whatever size TB I want)
LT1 ALUMINUM or Cast Iron heads ported, polished, gasket matched, Valve seats cut three angles, New polished stainless steel valves, new springs, retainers, and keepers.
Scat SFI Flywheel
Professional Products SFI Hamonic balancer.
Crane roller rocker arms.
Hardened pushrods
Stock LT1 oil pan, timing cover, and valve covers

He said he will go with forged flat top pistons and a forged crank for an addition 475 total but did not specify a brand. Is there any concerns I should have or doubts you guys have? Hes willing to work with me 100% Id just like to know if I need to worry about some of those parts because I am geting a good deal on the fresh rebuild. (my goal after headers exaust intake TB injectors tune etc....all motor is 400RWHP, is there any chance of geting that without having to worry about any of THOSE parts going out?)

Other notes from the builder....
Machine work: balanced rotating assembly, clearanced for the stroke, cleaned and inspected, bored/honed, align honed and painted any color you want.

A complete engine would also need headwork - Valve seats cut three angles, guides checked and replaced if needed, port/polished and gasket matched to the intake.

MachinistOne

Even at the maximum power level that you will reach with that motor, those parts will be just fine...I don't use Eagle parts. The Scat crank is most likely a series 9000, which I have in the 383 in my truck, it's a good crank although it is cast as opposed to forged. My personal preference would be a Callies crank, manley rods, and Wiseco Pro-tru pistons are a great piece for the dollar spent. You would be better off buying the GMPP LT4 hotcam and head kit for $2400 than paying him to port those lt1 heads. If you want more specific info PM me.

94zgreenmachine

The bottom end sounds fine. Have a good foundation. The power is in the cam and heads. You will not be better off, buying the lt4 head and hot cam. You will not make 400RWHP with that combo. The LE3 combo for $1850 will get you to the 400 mark. My machinist wanted to do my heads and said he'd do them for 650 but I was a bit reluctant to give them to him. You just can't put a grinder to them and get awesome heads. There is some knowledge that needs to be had to port heads. Every head would be different and he wasn't quite up to date on LTx stuff, at all. He kept trying to sell my Top proline std. 23 degree heads. LT1 are different. I instead chose Lloyd. I have not heard one thing bad about him. I have talked to him several times on the phone and each time he impresses me with his knowledge and resourcefulness of LTx info.
You can get the lt4 kit but you will only make 400 or so at the flywheel.Now, if you were to turn around and port those lt4 heads, you would make more power than lt1 castings fully ported.LT1 ported are better than stock lt4. It's only after port work on lt4 were they will outperform the lt1 ported head.
Another thing to keep in mind is going to be your dynamic compression ratio. It is different than static as dynamic takes into account the timing events of the valves. Try shooting for a 9.0:1 max for dynamic on the lt1. For example, In my 383 I couldn't have my cam designed till we knew deck height and the piston cc. After a slight mix up with my 4 bolt cap conversion they had to deck the block again so I ended up with a deck height of .010 in the hole.Using a MR.Gasket 5716 gasket .026 compressed my quench is good at .036. Between .035 and .048 is going to be good. After all is said and done a lot can be done with the cam to dial you in for the dynamic compression. Your real power will come from the head and cam.
As I have learned thru the whole process, you can't just throw parts together and have a great engine. You may have one that runs and works, but if you are trying to ring every bit you can, you need to make the whole thing work together. Match parts that compliment each other.
Talk these things over with your machinist. If he is willing to work with you, you should be on your way. I would definately recommend asking on this board(there are many knowledgable members) questions about what works and what doesn't. Good luck

LenT1

Thanks for all the great info, that is a lot of help already!

As for the head and cam discussion, you say its like 1850 for the LE3 combo...does that include a cam?

Everything I mentioned up there (using my existing block and heads) the machinist is willing to do for $4050 That includes the rebuild into a 383, the port jobs, forged crank and pistons(unsure of brand) and a cam. He has shown a couple cam options but I can just throw in an extra $100 to upgrade to pretty much any cam I want.

What id like to know is if he does a good port job on the heads will it be worth going that route for the price range alone rather than spending almost 2000 on the LE3 heads, if the power difference is that much different for the LE3 heads over ported stock then maybe I should get it built with ported stock and upgrade to better heads later? Will I be anywhere close to the 400 mark with stock ported heads and an awesome cam with the rest of that setup? Budget is an issue as usual....

MachinistOne

Exactly.

I misread your first post, no, the GMPP kit will not make 400rwhp, it makes 340rwhp. It is a good cost-effective proven way to get there though, and like is said above, it is matched components that you know what the result will be.

Comparing ported LT1 heads to un-ported LT4 heads is like comparing apples to oranges, yes you can always do more work to a lower-grade piece and come up to something comparable. The LT4 heads do promote better intake velocity which is important for making torque down low, the LT1 heads have the .100" lower runner and will not make as much torque if ported to match the LT4. The LT4 heads can pick up significant flow with some mild bowl work and a radius valve job. If you are trying to make 400rwhp, the LT1 heads even ported will not get you there...the LT4 starts out at 195cc on the intake runner and can be ported to support 400hp. As you stated, cost is an issue and 400HP is not cheap. This motor is going to wreak havoc on your fuel map, you will NEED to have on dyno w/ AFR tuning to keep from hurting it. That is another added $800-1000

Just out of curiosity - what are the smog laws in your state, here in CA, they just restricted us even more....they make the car pass a manifold vacuum test and a on-dyno speed test to check for larger than stock camshafts. Basically as of this year we may not be able to do any more than 340rwhp NA on cars that have to pass smog.

LenT1

Florida baby, and as far as I know there has been no emissions for a little while, as in I don't have to pass ANY test, if the car is insured and can roll down the street on its own, its legal

Ofcourse theres the usual sound laws and underglow kits they can nap ya on, but who wants a glow kit on a trans am lol....

BTW what does a set of used lt4 heads run?

SS MPSTR

400HP isn't too bad, but 400RWHP is not cheap by any means.

If there is a will, there is always a way around the regulations. It too is not cheap.

94zgreenmachine

Yes, That is using your heads and a cam. www.eportworks.com . Check it out.

Sorry man, but it been done with stock lt1 castings. If you read my entire post I do state that lt4 heads ported will outperform stock ported lt1 castings. Lt1 that are have been ported out have been enlarged to larger than 170 cc. Lloyd has been getting them to flow in the 275 cfm range which is huge compared to stock. Lt4 can flow more yet. www.eportworks.com Check it out. Do a search you'll come up with some stuff also. Too bad the M6 makes more power than the auto cars do but 400RWHP can be done with stock castings and cam.

WS Sick

The parts list will be fine , I would opt for a standard volume oil pump though it is more than sufficient.

As far as him porting the heads, if he is good with traditional 23 degree heads and gets excellent flow out of them, he can port LT1 heads sufficiently, look at some of his other work and see what they flow.
Does he have a flowbench? If he doesnt have a flowbench then I would take the heads elseware and just have him prepare the shortblock for you.

One other thing to consider is fuel system, upgrade to at least some SVO 30# injectors and a strong fuel pump if yours is questionable.
The price he shot you is pretty decent, I did all my work myself and am just a few $ under the price he shot you.

Tuning it I would get a base toon through the mail it can keep the motor alive until you get to a Wide ban to data log and make changes.

LenT1

Thanks again, he said if I want I can send the heads elsewhere to get ported and then back to him to install with the rebuild, he will obviously take some money off the tab for that too.

BTW I have an M6...


I'll e-mail the guy and see what the prices would run without him porting the heads and me supplying them, It should be a bit cheaper but im not sure how much...Also I notice he doesn't mention the brand of springs either, would I be better off buying a good set to match the LE3 setup and have him use them istead also? I would just have it build me the shortblock but I added up the prices and to get it thrown together for me after I get the heads and stuff will push the price much higher, since hes willing the port the intake for free and everthing like that.

If you guys think the LE3 is the way to go for the price then I will get that instead. Im assuming its better than lt4 heads stock but not LT4's ported? What would PORTED LT4 heads cost? (I can just do a search just asking while your here :P )

94zgreenmachine

Lloyds price includes a new cam, springs, retainers. Basically rebuilt heads with porting.The heads will be completely assembled ready to bolt on.
You may be able to find lt4 castings somewhere but good luck. The other alternative is to buy new heads for approx. 1300. Then add the cost to port the heads. Lloyd does do just port work also which is cheaper but with a bigger cam you are going to need different valve springs etc. Call him and talk to him. He is very flexible and will not talk you into buying stuff you don't need. Just be honest with him about what your goals are. Your price will vary with how you decide but you can ask all you want, you won't know till you talk to him.

Revolutionary

Your parts list looks pretty 'normal' for a middle of the road engine and should live just fine fine in the HP range you are looking for. The main thing I would question about the short block is to ask your engine builder how he is going to balance it. Make sure if he is using a Professional Products balancer it is the LT1 type - not a generic SBC style. We build an average of 4-5 383's a month and about half of these at LT1's. Not a big shop by any means but, I would just make sure your guy knows the couple of special things that an LT1 requires. We use a lot of the Eagle stuff and aside from having to open up the small end of the rod for more clearance, it does great. I don't really use the Scat stuff mainly because I don't like the way the cast steel carnks look. Although I'm sure they hold up well.

For your heads, follow the advice above. The LTx heads are not shaped like your old SBC castings and require a different porting strategy. Find someone who knows LT1 heads.

ABA383

I just made 400rwhp/430rwtq at 6100rpm with hp #s still going up...I broke my drivesahft in half...Anyway, that was on a rich/safe 12:1 a/f ratio base tune from Joe Overton. Bottom end is a 10 year old LPE 383 w/ Callies crank, Oliver 5.85" rods, and JE pistons. Compression is 11.2:1. The LT1 heads were originally done by LPE in 1995 2.00/1.56 valves, now freshened and ported again by E.B. Porting with a somewhat small cam by Joe Overton and 30lb Accel injectors. Car is an A4 with a Vig 3600.

You goal is very attainable. My set up should make 420rwhp/440rwtq when all is right. Check out Lethalefi.com also to see Joe's stuff, too. There is a reason he is the record holder for N/A Lt1 F-bodies...Good luck..

--Alan

94zgreenmachine

Amen!

94zgreenmachine

I kinda forgot about Joe O. He does have some awesome prices on heads and cams ,again, he knows his stuff too. Like what was said above, he is the record holder.....