GuitsBoy

iTrader: (4)

My guess is not too much. That cam is a baby cam. Itll probably act like a stock ls1 cam in an engine that big. Also, those heads may not have big enough valves, and the combustion chambers may be too small, but i cant really comment on that specifically. If you dont already have heads and cam, dont get these. Get purpose built stage 3 heads for big displacement motors, along with a monster cam, which will have great street manners in a big cube motor.

-T

JS

iTrader: (4)

What about a LS6 heads with Stock LW GM valves,good dual springs and then opened up to a 4.0 bore.Then flow the ports via a 4.0 bore and get the correct cam (EG.24X/24X 6XX/6XX )for the setup,I have a LSX/90 on my car now so I dont need an intake.

What would a 11.1CR 402 like I just described make as far as HP/TQ.I think the 2.0/1.55 valve will be fine as long as I open the comb chambers up and have the heads ported alittle farther?

pkincy

iTrader: (1)

[QUOTE=GuitsBoy]My guess is not too much. That cam is a baby cam. Itll probably act like a stock ls1 cam in an engine that big. Also, those heads may not have big enough valves, and the combustion chambers may be too small, but i cant really comment on that specifically. If you dont already have heads and cam, dont get these. Get purpose built stage 3 heads for big displacement motors, along with a monster cam, which will have great street manners in a big cube motor. QUOTE] talking of the 5.3 stage IIs and the 224/225 cam.


I have a very similar situation. Have TEA stage II heads and TR 224 on 114 cam. Blew the SB and going to 402. Pretty ez decision that the cam is too small for a bigger motor. So I am going with the Torquer. And when I talked to Brian at TEA he recommended a stage III 6.0L since it is already optimized for the 4 inch bore of the 402 and the bigger cubes. And after all it is just money right! <groan>

BTW, the bigger 6.0L chambers will require a flattop piston, but Kris fixed that right up.

Perry

GuitsBoy

iTrader: (4)

JS, I would imagine with a good size cam you probably could run stock 2.00/1.55 valves and the motor would still make some devcent power, but in my opinion, those valves are definately gonna be your restriction. But then again, who knows. For all I know it could work perfect and the smaller valves could give you a super flat torque curve as an added benefit. I really dont know enough about it to say one way or another.

Bad30th

iTrader: (13)

Yeah, I've already got the heads/cam on my current setup. I could sell them (and the wet kit I probably won't need anymore, heh). Good call to step up to a heads/cam setup more suited to getting power out of the bigger cubes.

Indeed, well said Perry - it's only $$, right ?

Can someone answer if/how well the 5.3L heads milled .030 would work on the 402 with a (much) bigger cam ? My current heads flow pretty well, 300+ cfm, making 410rwhp/415rwtq on the 346 with the 222/224 cam. I think they are the stock valve size.

Grr, the cost is starting to slip out of reach if I have to buy a whole new setup (402/heads/cam/intake kit/injectors).

What about upgrading the heads a little later, say next year or whenever I win the lottery ?

Bad30th

GuitsBoy

iTrader: (4)

I think its more a matter of optimization. Just a shot in the dark, but it may be a matter or 25 or so HP, assuming a good size cam. But when you look at the grand scheme of things, the difference between 450 and 475 RWHP is not the end of the world. Youll still have plenty of torque with a real flat curve, and after all, isnt that the allure of a big cube n/a motor anyway? Use what youve got and later on, you can always "optimize" when the budget allows.

pkincy

iTrader: (1)

I think that is spot on. I have a couple of 383 LT1s and even though my H/C 98 had more hp (over 400 rwhp to the 383s 380 rwhp) the stroker motors felt much stronger on the street since they had more off idle torque. What I am after is a car that will leap forward when I crack the throttle and the 402 will do that no matter what heads/cam you run initially. You will feel the 50 ftlbs of torque at all speeds that you have added. So you miss 2 mph of trap speed for a year until you can buy new heads and a cam, so what unless you make your living drag racing.

Perry

DrkPhx

iTrader: (15)

If I spend the big bucks for a stroker it better put out some serious HP. Why not run a max effort stroker with a big cam and heads (like the AFR 225) and take advantage of the extra cubes? That's optimizing the setup. Putting 5.3's with small valves and a 224 cam is really selling the 402 short. I guess to each their own, but I want that extra 2 mph in trap speed and I don't think that's too much to expect. I can't justify spending $5K plus for a stroker for 450 rwhp and feeling good about it.

JS

iTrader: (4)

I might not build a 402,I wanna find out the correct rod/piston speed and stroke combo to run a 4.0 bore.It might be a 3.75 or possible a 3.80 stroke,I would give up 10 cubes to have the correct setup.I think at that point,say a 385 might be the best choice for me along with the little valves and the right cam,lsx and big tb.

I believe u could make big power (500RW) with this combo shifting at 6800.

GuitsBoy

iTrader: (4)

DrkPhx, there's more to it than just a peak HP number. If he wants to save a few bucks initially by reusing parts he already has, IMO, so be it. I mean, you wouldnt tell someone with a stock LS1 not to do boltons because they wont reach their full potential until you add heads and cam, right? Youre right about the 5.3 / 224 selling the 402 short, but I dont think its enough to say that the stroker is not worth it. Its still going to make sick power, its still going to have a sick torque line, its still going to be a monster EVERYWHERE in the rpm spectrum, and possibly the nicest part of all, its still going to be a brand new motor! If money wasnt an issue, then yes, Id agree to go big or go home... but since it is a consideration, and he's already got the heads, who not adapt them to the 402 and save $2K for the time being at a relatively small performance hit, while still enjoying the other benefits of the new big cube motor.

But thats just my opinion.
-Tony

DrkPhx

iTrader: (15)

Guitsboy - Good point. I didn't mean to be harsh to anyone. You're right though, ultimately it's what you can afford and God knows how expensive these LS1's are to modify. I was adding up the cost for a stroker and when you take in consideration the other parts like intake, new injectors, new fuel pump, transmission, rear end,etc. it gets real expensive in a hurry.

GuitsBoy

iTrader: (4)

Dude, you wernt harsh at all... theres alot of good points being brought up in this thread, not that its got anything to do with the original post anymore... But Yeah, horsepower definately is expensive... but i guess thats some of the fun. Not everyone can go out and buy a stroker motor for $149.95 and put it in their '83 escort. Modding, conceptually speaking, is a bunch of compromises. You try and get the most gains, in the areas that matter most to you, for the budget you have. Otherwise we'd all have parachutes and wheelie bars on our daily drivers.

Bad30th

iTrader: (13)

Thanks for the insight fellas.

Good advice here - it would probably still run OK with my current heads and a 24x/24x 6xx"/6xx" cam (or less so with even my current 222/224) but obviously wouldn't be optimized... Then I'd also have to tear the thing down again to do new heads and/or cam later on... Might be worth the extra expense up front to put some nice 6.0L TEA heads or some AFRs and a better suited cam on.

Now, what to do, what to do.... Lots to think about. My current setup is still solid and not having any problems for now except the horrible piston-slap on cold startup...

Ah, if only money was no object. Heh, but like you said GuitsBoy, if it wasn't we'd all have $149.95 George Foreman stroker kits and wheelie bars/chutes on our daily drivers, haha.

Hey SDPC, how long is this price good until ?

Hmm, maybe that 5k would be better spent on a ATI/Vortech... I'd still need new heads to run some decent boost (11.1:1 now). Big cubes just sounds so much more tempting...

Bad30th

JS

iTrader: (4)

My shortblock was honed,ringed and bearing 1000 miles ago.
Its noisy under cold start but once the pistons get heat in them its quiet and the engine has great psi and doesnt burn a drop of oil.

LS1's piston slap,its just one of those things.
I'm not worried check out the sig

horsepower

Okay, welding bosses in the LS2 valley is possible. The bad news is that the process to accomplish this without effecting the cam bores or lifter bores from the surrounding weld shrinkage is way too time consuming and $$$ to do more than once. We are moving onto something else, easier and much safer - I'll report if it works. Anyway you look at it, the exotic design of the PCV shouding (underside of valley cover) will have to be ditched to make room.

racer7088

FWIW, we can't get enough Iron blocks right now since people here have gotten tired of the aluminum stuff falling apart quite frankly (mostly power adder guys) and not being able to hone them much if they do. Also the iron blocks are much stronger and do not swell up like a sponge when they get hot and lose so much oil pressure. The weight is nice but the aluminum blocks never seem to make as much power. I am sure the SDPC engine will work absolutely great but a lot of people just won't do the aluminum stuff with us right now. The LS2 block is cheaper for me than the Iron.

02SOMWS6

iTrader: (6)

Thats a great deal for a 402 shortblock......... but what about next year when the 7.0L block will be a normal block and the C5R pricing will go away? I'll start to save now for a 7.0L short block.Someone out there needs to get started on a stroker kit for the 7.0L Whats the max that the 7.0L can be stroked to and do you guy's think you will sell a 7.OL shortblock.

Squintz Palladoris

iTrader: (1)

Charictaristic of forged pistons there JS
There supposed to make noise when they are cold.

Brad

JS

iTrader: (4)

I'm running stock pistons,not forged.
Forged will make even more noise until warmed up...

Slowhawk

iTrader: (12)

I've got one of these 402 shortblocks on order for my Vette.I don't see a problem pushing one of these at 700rwhp/pump gas all the time.We will see the longivity by what I give it