Actually, I've heard reverse splits are good for LTR setups. Helps to catch more of the reversion waves. Lifts are another matter though. If I were you, I'd be inclinded to use 1.6's on both sides. Maybe even 1.65 or 1.7's on the intake side.

AFR's flow dog-nuts on the backside. Don't see why you'd need extra on that side.

BTW: I don't dislike your cam option. Using the "easy" lobes of the hotcam (compared to agressive lobes), is a reasonable option -- especially if you want to max out your longevity.

Are you using the GM or TPIS head gasket? Looks like you ground the chit out of the tops of those SLPs! That sucka outta pull like a *****! In fact, from what I hear, you'll probably be able to break 'em loose anywhere in 1st by just mashing the throttle. (No clutchwork req'd).

When do you plan on having it running?

gp

 

cool beans

 

If the heads flow 274cfm at .500 (I imagine 270cfm+ at the .492 I'll have with the 1.5 rockers) do I need more lift? I'm not going to spend the $ to have the flow checked on my intake, but I'd be surprised if it flowed more than 270cfm, or am I wrong will my intake setup flow more than what I'm predicting if it will you're definitely right I'd want to take advantage of it.
GM head gaskets. part number 10105117

 

Anyone care to approximate final HP and TQ numbers?

 

I'll guess 355 RWTQ at 3200 and 285 RWHP at 5200. You'll have good torque at a decent RPM due to the medium runner length with porting, great heads, and modest cam. Your RWHP won't be super high due to the intake being a restriction at higher RPMs and your IVCP won't be very late. Basically your heads can outflow all other components of your combo, so the powerband is determined by intake manifold flow dynamics and cam timing. I had a similar intake and I could only get about 250 RWHP through ported 113 heads when I had a 350.

 

I sure hope it's better than that, considering I've seen L98 cars with bolt ons and exhaust come close to those numbers.

326 rwhp 399rwtq- LTR intake and ported 113s on a 355
http://temp.corvetteforum.net/c4/joe90/index6.shtml

 

I bet thats close. You wont be using the full potential of those heads so the small cam and intake become the weakest link.

 

I am hoping it will make more then 285/355. My stock untouched L-98 with the only mods being exhaust made 240rwhp/331rwtq.

If it's tuned well. You will break the 300rwhp mark!

 

Well I'm to this point now (see pic). I won't be able to do anymore till next week though, goin' fishin' with the boys for the weekend. First job next week will to get the tranny out figure that will be the optimum time to do the cam, I'll be able to tilt the engine. I know some people either clear the crossmember when pulling the cam or just have to jack the engine up a little, but for some reason mine isn't even close.

 

The cam from that engine was a 225/229 on a 113, so that is 7 more intake degrees duration than yours. They also had .555 lift with unknown head flow. Some of the unknowns in your engine are how much your intake flows (you say it's a heavily ported Accel {which is about as good as you can get without being a HSR or MINIRAM or converted single plane}), how well it's tuned, atmospheric conditions on the day of the dyno run, and exhaust backpressure. I'd say if everything was optimal you could get close to 315 RWHP, but your occupation says you're an "outta work BUM", so I'm guessing you don't have the resources at this time to chase down the last few HP. I think the documented effort you are referencing was more of a well thought out effort, while yours is a multi step approach to finally arrive at a 383 with some more upgrades later on. In any case, you have some great heads to start with and I don't think it would take much to better my initial estimate of 285 RWHP.

 

That's how I did my LT1. I guess the clearance is different. I just loosened the motor mount bolts and jacked it up a couple of inches.

 

It's no big deal that I have to pull the tranny I've got a new blue tag to put in anyway.

 

It is stated in the rebuild the heads only flow 220 on the intake, exhaust isn't mentioned. Don't know how much that matters.

And I know I shouldn't have asked what peoples opinions were if I didn't want to hear them.

 

We have an L98 A4 car in our club that pulls around 320+rwhp and around 375rwtq. Same camshaft and similar TPI mods. You should be able to pull down around 320 to 330rwhp.

 

I think you should get over 300rwhp. And it should make alot of torque with the long runner length. One cool thing about the new AFR eliminators, the base street port 195's flows the same or more than their old 195 comp head which was $2000 2 years ago.Talk about bang for the buck. Dane you will be happy with your new engine. And if you do a 383 down the road, you have the perfect heads for it.

 

That's closer to what I'm hoping for.
ross did make a good point though I don't have the local resources (or at this time an excess of funds) to do a proper tune I'll end up relying on a mailorder tune and hoping it's right.

 

Well there's something about the ASM runners (as used in the link you posted) that perform well. You really do have to work over SLPs just to get them equal to the ASMs. One question is how much better did you make them? If you didn't get all the way thru the tubes, you will have a restriction in flow -- especially at higher rpms. Ehoning would help that.

The cam was a longer duration and had steeper ramps. That's worth some decent power. IMO, it's as much to do with the lift as the duration. What I sense you're not getting is that steeper ramps gets the valves open sooner/longer. 1.6rr with help that! At the lower lifts, the cam used in the link may have 15-20 degrees more duration at .200"-400" range (than a hotcam with 1.5rr). That's a lot. This is why I feel certain you NEED 1.6's on your intake. If you already bought the rockers, put the 1.6's ON THE INTAKE!.

Don't talk about what your intake vs heads flow, talk about how LONG they can fill the cylinders! MOST of the cylinder filling occurs at lifts less than the highest one.

I think the SLP/AFR combo has the potential of 320rwhp/390rwtq (more with a short block). Without the honing and correct cam, I believe you'll be around 290/360rwtq. That means I wouldn't bet against what Ross thinks.

FYI: The FIRST intake -- with a good cam -- has a potential closer to 350rwhp/400rwtq. And, that's out of the box.

 

The car I quoted from was tuned on the dyno. I was present and watched the horsepower climb as the tune progressed. The car actually was running out of fuel at that HP level because of a dirty fuel filter. IMHO you will need a good tune to acheive the numbers unless you are lucky with a mail order tune.

 

Hey Gregg
So do you think a different cam? I already have the RRs and cam but I wouldn't be opposed to selling the cam (I picked it up $150 and can't imagine I'd have much trouble geting that back out of it) and getting something new if it'll make a notable power difference, just remeber I've got the split ratio rocker arms I'll be using.

What do you think of this Crane, figure with the 1.6 on the intake and 1.5 on the exhaust I'd be looking at .543 intake .528 exhaust

http://store.summitracing.com/partde...1&autoview=sku

 

To be honest, I believe you have to make a decision on longevity vs power. You can gain power with a bigger cam. I suspect there's 10-15hp/tq to be gained from the cam. Same amount if you ehone the runners.

Or you can sell your intake, install the FIRST, and pick up a bunch!

The cam you linked has too much total duration for a TPI setup. Look for a single pattern cam in the 214-218 range. Actually Lloyd Elliot sells a 218/222 cam that would be good too. 544"/510" with your rockers (112LSA -- just like the hotcam.) I'd say the 260 or 268XFI cams would be good too, but they're designed for 1.6's on both sides. Not sure if 1.5's is a problem. If not, that's another choice.