I'm picking up an L98 350 bottom end from a friend of mine. It has roughly 140K on it, so I'm planning a rebuild. I'm on a serious budget (around 1K), but I want to make near 300 rwhp.

Now, here's what I have. My current 305 has out-of-the-box World Products S/R Torquer 305 heads. They have 58cc chambers with 1.94/1.50 valves, screw-in studs, good springs, and (according to World's site) flow a bit better than the L98 Vette head. They have the '87-up style intake bolt pattern. I also have SLP runners on the 305.

To stay within my budget, I'd like to reuse the Torquer heads and SLP runners. The new 350 would have pistons to give me around 9.5:1 compression with the 58cc heads, and I would probably buy an Edelbrock high-flow base to go with the SLP runners. How would this combo run with a ZZ4 cam? Would I be able to get close to 300 hp at the wheels? I think it could be, since the ZZ4 is rated at 355 hp, and this would be basically the same motor. I've searched, and seen a few members have used this cam, but I haven't seen any of them post dyno numbers or quarter mile times afterward.

FWIW, my car already has a World Class T5 and 3.73 gears in a 10-bolt.

Let me know your thoughts!

 

I say if it was tunned you have a nice 13.5ish setup there. I have all the stuuf you want . But I ported and siamesed the edlebrock runners. You won't see anywere near 300 rwhp with that setup. Maybe like 270ish ? Check my sig I have the 3.73's aswell .

Untunned I have 251 rwhp. And untunned and with 3 people in the car with bald tires I hit 14.4 @ 95 in the 1/4 . It's a real bitch to learn to launch it ....especially with the higher gears AND TPI .

 

First, I just did a G-Body T5 swap. What did you use for clutch pedal & linkage?

I think it will be hard to see 300 hp, I had similar set up with 10:1 & other similar items ZZ3 cam, 52mm TB, Headers, big mufflers, duals, 700r4 trans. 3:23 gears. Motor was align bored,stressplate honed, balanced, forged pistons, manley rods, sportsman II heads 64cc, 24lb injectors, custom chip. All in my G-body. Rear wheel dyno= 224 hp, but the torque was awesome, 335 ftlbs. Thats the long runners. I was never disappointed with performance. The torque will get you movin. Your combo should be somewhere close to that, maybe a little higher with the good intake.

Remember quality machine work lives longer and helps make the most of your combo. I would consistantly rev to 6000 rpm without any part breakage. FWIW my machine shop bill was over 1k.

 

Why would you rev to 6000 . When you are only makeing power to 4900 ( tops) . Thats the TPI top end . My ported aftermarket unit only revved that high( well made power to there only ) .



Regardless of what its in ... you will like the nice feal of that torquey TPI

 

For my T5 swap, I used an '83 F-body V8 T5 mechanical linkage bellhousing and pedals/Z-bar from an '81 El Camino. I have some good pics on my website.

I'll have to investigate further and see if there's maybe a better cam choice. It's a shame that a ZZ4 crate is rated at 355 hp, and it would only put 270 to the wheels through a manual tranny with a TPI on top.

 

Serious work would have to be done to those runners - in other words a total port job making them just big plenums.

Then you might see a number closer to 300.

 

What if you kept teh stock pushrods and crankshaft and buy some forged pistons and moly rings. Then throw in something like an lt4 hot cam. Keep your current heads and lay down some money for a stealth ram or even an lt1 intake. Think this might work? A grand is a realy tight budget... I've spent over 4k already on mine and it seems to never end.

PS: That tranny is gonna be the winkest link!

 

Because occasionally I love to do nasty burnouts & sometimes in manual 1st, well it hits 6000. I'm not even hinting that any power is made up there, just that it stays toegther. Good machine work saves parts.

P.s heres the dyno run. No tuning was able to be done other than what took 1 minute to do. i.e. fuel pressure & timing.

 

Put it in second, go to 4500 RPM and drop the clutch.

Might break something, but that's how a lot of guys that compete in burnout competitions get it done. 70MPH burning rear tires, car can't hook. FUN!

 

I see why you hit 6000 now


I got forged pistons in my setup I think it really helps it build revs faster .

Here is my dyno graph with the ZZ4 cam in it . I didn't get to tune it . It still had the stock 305 .bin in it .

BIG difference in the shape compared tothe other one up there.

 

i'd try a bit bigger cam. and have those heads really opened up with a good port job. zz9 cam aint bad and would good with that TPI setup. port those runners out alot too and the base to match. there is a TON of room there to port out and you should do it to get as close to 300wheel hp as possible. i dont think you'll see 300whp but some where in the 260-270ish range for sure with a zz9 cam. with that torqe form the tpi setup, you'll still run some good ETs

 

Hey guys just a question, Is that a chassis dyno sheet or a crank dyno sheet, and why dosent the HP/TQ cross a 5250rpm, because if it dosent I would be worry about it not being correct. Just currious....

 

Isn't it..

HP = (RPM * Tq)/5252

I might have hp and tq switched around..

 

mine was on a chasis dyno

 

DIRTBIK3R, Thats what I was speaking about, look a the previous dyno sheets that was previoulsy posted, looks like HP/TQ intersects at 4000 rpm... Makes me wonder what the deal is, looks like the dyno was calibrated wrong....

 

Chassis dyno for mine. Never really paid much attention to intersection of HP & TQ. I left the dyno disappointed & started on replacement HP right away.

 

why would hp and torque intersect around the same rpm(supposed 5250) for every cam/head/intake(motor in general) cross at the same point? - It wouldn't that I know of. - anyhow, the zz4 was rated @ 335hp flywheel. With a TPI that hp number fell, but the torque number elevated. - still not wheel hp. either/or. - I would expect around 270ish. - you outta look into spending some at home time porting those heads and intake. DIY porting saves major $ and makes for solid power gains, as long as you do some research and follow the proper steps.

 

Thanks for all the tips and info guys. I'll keep everyone posted as it progresses!

 

HI SHAGWELL, It has to do with the way the the numbers of HP/TQ/RPM/TIME works out. Look at all the GM/FORD/MOPAR engine dyno sheets and you will see that is where they intersect. If the mathmatic formula is changed then so will the numbers, therfore when you see a sheet that does not intersect, sometimes the dyno person is trying to make the dyno happy, so the customer dosent feel so bad when the numbers do not come up so good, after he has built a engine combo that may be lazy due to incorrect parts selection, or could just be an error on the part of a new technition. That the reason I questioned the previous sheets, I was just currious about a chassis dyno because im not sure if it the same, I think it should be but wanting to know from maybe someone with first hand exp....

 

NO no no no.
The units on the left are for power and on the right are for torque. They are on different scales which is why they don't appear to cross at 5252 rpm. But if you look at the numbers on the correct scales, they cross at 5252.

 

Sorry looks to me that it crosses at about 4k, maybe im just reading it wrong, but to me it looks like HP is about 170 and TQ is about 320 or so at 5250. Like I was saying if it crosses there then your good to go, Heck I may just be reading it wrong, im just going by the RPM at the bottom and the HP on the left/ TQ on the right.

 

Its the scales, they arent the same spot for HP and TQ. Typical. If you shift the scales, they will cross at the right spot.

In other words, read the HP at 5200, and then read the TQ at 5200, make sure you are reading the right scale and right graph line. They do cross, both cases above.