L98 Engine project for the winter

[KQS]

Hi all!

I'm planning to do some majr modifications on my stock '89 Corvette with L98 engine during the winter, and i'd like to ask for your opinion about my plans. The parts i want to exchange in the first stage:

- cylinder head: either Trick Flow 195cc or AFR 195cc or Edelbrock Victor Jr. 215cc with 70 cc combusion chamber
- high volume oil pump (melling)
- high flow water pump (edelbrock)
- high flow fuel pump (from ecklers)
- roller rockers
- 30 lb/hr injectors
- new camshaft
- some porting/port maching/polishing job on the plenum/runners/manifold

Second stage (maybe during the next winter):

- TPiS MiniRAM intake system with fuel rails
- adjustable fuel pressure regulator

Last stage (even later....):

- supercharger or twin turbo setup
- 383 stroker setup

According to the Camshaft: What duration do you recommend for this setup? And what roller rocker ratio? I'd like a streetable car....

I'd like to build the first stage so that it would suit for the last stage. Any idea, recommendation about this "plan"? Any constuctive critism is welcome!

Thanks for the ideas in advance,

Best wishes:

Gábor Kovács

 

[-=Jeff=-]

You have some good plans, but one thing i would recommend is to get everything that works together, search the forums there is a lot of info. Make sure the intake, heads and cam will work well together, the combination of parts is VERY important to a great running car.

That said, the 195s are raised runner I believe, be sure the Miniram can be purchased port matched for them. Also once you decide on the heads and intake then you can start searching for the cam. I also recommend buying the parts then when you have ALL of them tear into the motor.

Hope this helps

 

[rrubel]

Jeff's right... decide what you want the car to do and then buy all the parts that have been proven to work well together. In my research, I've been told to not get 215cc heads unless I'm planning to REALLY open up the engine (ie, 383 or similar) becaseu a) they'd be a waste and b) they may not match well to a mildly ported manifold. Do you want an engine that runs to 6500 RPM with a ton of high-end HP, or something that keeps a lot of torque down low for off-the-line performance?

I settled on an Accel SuperRam plenum, runners, manifold (base) and Accel 74219 cam. This package requires 1.6 rollers for full effect, so that's what I got. I'm also getting DART Pro 1 heads (64cc) because they're less than half the price of Trick Flows but flow more than well enough for my needs. Then I added Lingenfelter's titanium spring seats and double springs because that's what they recommend for the Accel setup. The cam, btw, is advertised as having a mild idle and good for 6k RPM but still with a decent amount of low-end torque. I am told to expect around 425 HP from my setup.

Incidently, Lingenfelter sells all the Accel parts, but you can get everything they sell for at least 20% less if you shop around the web.

Now, I have also been told that the SuperRam is an absolute bear to install. Steve1ph on this forum just completed one and had problems; I'm still going to attempt it.

There's been a thread recently from 69MyWay in which he described using a converted LT1 intake instead of a Mini-ram for a fraction of the cost. If I didn't already have almost all the parts I need, I'd have probably gone that route.

[RICHR]

 

[Mad-Mic]

some of the things i would skip till you are ready for the stroker motor.

don't worry bout the high flow fuel pump or injectors. our vettes current fuel system is good for over 400 hp. if you swap out and don't know how to tune your car will run rich and you'll be chasing it down for awhile unless you have the scan tools and or can read the plugs to see whats going on with the fuel system.

add an adjustable fuel pressure regulator in plan 1. this will help you bump the fuel pressure up enough so it will run right. also add the 52 mm TB to help with the breathing. better get the big mouth base and SLP runners to help the motor breath and siamese the runners and base for full effect and hp.

cam selection i would go with the ZZ9 cam or the ZZ409 cam which is basically the same as the ZZ9 cam but with longer lift on the exhaust side if memory serves me correctly with 1.5 rocker arms. get new pushrods and racing roller lifters and you'll have a true roller motor right there. you will need a new chip for this setup.

plan 2 looks good.

plan 3 forget the twin turbo setup unless you got ALOT of money to burn up. a supercharger will suffice with a stroked out 350 (ie 383 or bored over) a supercharger procharger setup from ati will give you as much boost as you need. Remember to get maximum boost don't go with high compression! 9.5:1 will do 8.5:1 will do better for high boost applications.

with plan 1 your looking at easy low 12's with a set of Drag Radials and a 2800 stall converter if you have an automatic. if you go with a high stall you better add a good transmission cooler!

good luck and let us know how it goes!

BTW there is a member here with a stock motor 89 vette running 13.1's so add another 100+ hp for plan 1 and that will be your ball park ET for the 1/4 mile

read this post here to see what mods he is running:
http://www.corvetteactioncenter.com/forums/showthread.php?s=&postid=283186#post283186

 

[vader86]

Cylinder head choices look good, but i wouldnt go so big with the edelbrocks unless I was going with a SERIOUS camshaft, and then only on a 350 built to rev like hell or a larger motor. (preferably a larger motor, but thats just my opinion)
But with a Miniram, please go with something bigger than a ZZ9.

Look thru the other cams on TPiS.com, see what their durations are, i cant think of them off the top of my head.
When you speak of streetable, do you mean emissions or what degree of 'lopeyness' can you handle?

1.6rr at least, unless you go with really stout springs for the cam, when you could go with 1.7rr.

As for the oil pump, you will find that the stock pump RARELY fails to put out the necessary pressure for anything but the most serious race engine. I am one of those who doesnt like the hi-volume stuff, I prefer the high pressure pumps. I run a Melling 55A pump, which provides higher pressure than stock, but still plenty enough so that i can keep it for my own engine buildup later.

Save the #30 injectors for the 350+ci engines. Youll run pig-rich with those on a 350.

Only replace the fuel pump if your car has high mileage or you believe something is wrong with the stock one at this point. Otherwise, save it for the 383, or just before.

Realize that you will need a custom chip/program made for any cam change and intake change.

 

[KQS]

What about an LS-1?

Thanks for all of you for the suggestions...

I think i'll include an larger TB and an LT-1 intake conversion in the first stage. I saw a suitable LT-1 intake with fuel rails, injectors and throttle body on E-Bay for 150 USD(!)Unfortunately i don't have the money right now - it cost a lot to import parts to Hungary (customs..) I hope i'll able to buy one during the winter (big money time ) )...

My first approach to the cylinder head is a 195cc with a 70 or more cc combustion chamber, because it'll more suitable for a blowed (super- or turbocharged) application than a 64 or less cc - larger combustion chamber is better for achieving a lower comression ratio.

The only reason to the 215cc Edelbrock head is also the blowed application. I think a larger cyliner head would be better for my "last stage" plans and i'd like to buy just one set of cylinder heads: it's almost impossible to sell these precious thing in Hungary.

The Camshaft (yes with a capital C it's VERY important ): choosing the right camshaft/RR ratio/pushrod lenght& diameter is the main reason i started this topic. According to my driving style, the low and mid range torque is a little more important than in the high RPM range. Of course the ideal solution is high torque during the whole RPM range...

Now I'm planning a camshaft with about 220/230 in/out @ 0.5 lift with 1.6 RR ratio. I think i'll produce an acceptable idle and good low/midrange torque without sacrifing the high end torque. This is something like the ZZ-409 (375 USD at TPiS). I saw at www.summitracing.com a similar camshaft made by Summit for just 80 USD. Any experience with these Summit cams?

Can anybody help me how to choose the right hardened pushrod set for his application? I saw there are pushrods in two diameter and a lot of lenght...

About the custom chips: I forgot to mention it in my plans.. Of course i need a special custom chip for my new car. Can anybody help how to create a suitable one? In Hungary i'm pretty sure i have to do it personally, because there isn't any experienced mechanical/electrical person around here.

Other plan: I saw a complete (with harness and ECM) LS-1 engine on e-bay for 4800 USD... Is it possible to build it into a C4? I think i should keep the 700R4, but i'm affraid it would be nearly impossible to connect the digital intstument panel to the LS-1 ECM - or it would cost a lot of work and research ot build the transforming logics. Did any of you hear about a successful L98 -> LS-1 conversion in a C4?

Best wishes:

Gábor Kovács

 

[-=Jeff=-]

cam selection i would go with the ZZ9 cam or the ZZ409 cam which is basically the same as the ZZ9 cam but with longer lift on the exhaust side if memory serves me correctly with 1.5 rocker arms. get new pushrods and racing roller lifters and you'll have a true roller motor right there. you will need a new chip for this setup.

Close.. the ZZ9 specs like this
Dur ar .050 212/226
Lift .483/.520
LSA 112

ZZ409 is
Dur at .050 226/226
Lift .520/.520
LSA 112

The ZZ409 will set the RPM Band higher then the ZZ9 by about 200-300RPM. The ZZ9 works well with the Miniram on a 350, I should know, that is my set-up

I do agree with Vader about a cam bigger then the ZZ9 for the Miniram, in fact I have a ZZ409 Cam sitting waiting to replace my ZZ9, but after being at the track on Sunday, I am keeping my set-up with the ZZ9..

I ran a new best of 12.55@111.69mph

I am happy with teh ZZ9/ Miniram combo

 

[KQS]

zz409 and a high stall torque converter

I think something like the zz409 will be suitable for my needs with a ca. 2500 rpm torque converter - this little baby will help me to get some respect from those german & italian sport car owners (Porche, Audi, BMW, Ferrari, Lamborghini etc.). But my experience is that here in Europe a Corvette shocks the crowd simply by its apperiance Its much more exotic here than the above mentioned cars

Any expericnce with the Summit camshafts? Summit has a 224/234 hyd. camshaft for just 80 USD.

 

[tntcorvette]

there is a big difference between a hyd. roller cam & a hyd. flat tappet cam.

 

[tntcorvette]

there is a big difference between a hyd. roller cam & a hyd. flat tappet cam.

 

[KQS]

tntcorvette

Can you explain it a little bit more detailed? I doesn't have a deep knowledge about the camshafts but i have to choose the right one for my baby... Can i use either the hyd. roller or the hyd. flat taaped camshaft in my car? How can i recognise them? What are the benefits & disadvantges?

 

[tntcorvette]

you car came with a hyd. roller cam, so you need to replace it with a hyd. roller cam.

The difference between the two types of cam's are the type of lifters they use (one a flat tappet lifter and the other a hyd. roller lifter), and the design of the lobe's on the cam.

Im sure there is more but that is the skinny of it.

Stick with a hyd. roller cam.

 

[KQS]

so hyd. roller...

Thanks!

The description of the summit camshafft stated that it's a hydraulic camshaft... Checking the kit/combo accessories, i saw it comes with flat tapped rollers - so it's a flat tapped camshaft... I'll have check the camshafts again for a suitable one...

 

[rrubel]

Um, what you just said is self-contradictory - "comes with flat tappet rollers". If it comes with flat tappets, then it's not a roller. Were you trying to say flat tappet LIFTERS?

Look at the Accel 74219, which is a roller cam.
[RICHR]

 

[KQS]

Right

Yes, you're right! That's what i wanted to write, but as you probably noticed in my previous posts i'm not a native spreaker and i sometimes (too often) make mistakes

 

[rrubel]

Not a problem! To be honest, you write English better than many native speakers I have met.

If you want an alternate source for products, you could check out
Competition Products. I just ordered a bunch of stuff from them; their prices are as good or better than Summit, their stock is higher-quality according to some racers I've talked to, and their people are very knowledgeable. They have a focus on small-block chevys being built up for racing (street/strip/track/etc). Not sure if they'll do international shipping, though. But you can browse their entire catalog online.
[RICHR]

 

[KQS]

Thanks for the great info - their product list and the on-line "printed" catalog is great! I've just posted them an e-mail about my plans.