esp42089

Hi all! This is my first post here on the forum, although I've been plumbing the knowledge here for a couple years while building my 53 Chevy. I created a quick album with a couple pictures that might give you some hints why a guy with a 53 chevy is here . If there is a lot of interest I can post a link to my build log, although I'm not sure if there are rules against that.

Jumping into it: I bought a 91 corvette manual trans donor car with ~140k miles and a recently replaced clutch. It ran well enough and it had everything I wanted for my 53. I grafted the entire suspension and drivetrain into the 53 and in the process of putting the L98 in, I did the following:

• wired it up to a Megasquirt 2 with a wideband O2 sensor
• stripped off all the smog stuff and the air conditioning (retained PS, alt, and water pump)
• installed cast iron 2.5" rams horns (truram) run into 2.5" exhaust merging to 3.5" single at the tail of the trans, breaking back into two 2.5" pipes behind the diff into Flowmaster Delta50s and out the back.

Everything is running great. After 3k miles, it has burned a negligible amount of oil and what's on the dipstick is still amber colored. It seems like it's healthy, but I want more punch out of it. I value throttle response and would like tipping into the throttle at cruising rpm (1600-2200rpm) to result in a strong surge instead of hesitation or lugging. This car won't see a track, autox, or dragstrip. It's pure street. I've scraped together about $3000 and have the wife's blessing so here is what I'm thinking:

• AFR180s with Manley StreetFlo Valves
• COMP cams XR264HR cam kit (including dbl roller timing set), magnum pushrods, and UltraPro rockers with 7/16" ARP studs
• Port match intake and clean up any casting imperfections, reassemble everything with new gaskets
• New proform balancer (I could use help here, I don't know what to get but mine is toast)
• Moroso 21811 Oil Pan

What do you guys think? I understand that I'm going a bit nuts on the valvetrain for how low the revs will be, but I feel like it gives me a very reliable, durable setup that won't wear out. I haven't talked to COMP or any of the pro's yet so there may be a specific cam they'd point me to. I'm hoping to talk them into a package deal since I'm buying the whole valvetrain together in one go.

How would you spend $3000 to sharpen up an L98? Or would you wait until you had a larger pile of cash to work with?

Pwnage1337

I'm not familiar with flow characteristics of Rams Horns, are they a good upgrade vs stock?

Only thing I would suggest besides what you have is headers, but again I'm not familiar with Rams Horns. L98 should make assloads of torque in your specified RPM range

thurman_merman

To make power with an l98 the first thing that has to be addressed is the intake manifold. There are plenty of threads on how to make 300hp with an l98, do some searching in the C4 forums and you should find them. I made 310 to the tires in my 91 and I spent ~$2k on an intake and a cam. If you want to make more power than that heads would be next or you could go the power adder route, supercharger would be a good option in a car like yours. What kind of power would you be happy with in a car with that weight? What does it weigh anyway?

esp42089

The trurams, from the dyno sheets I saw, are pretty much equivalent to 1-5/8" shorty headers. They fit in the car well and make pulling spark plugs very easy which was most of why I chose them. I think it's a pretty low restriction system, but definitely not as good as long tube headers.

The 53 was 3400# from the factory, but I pulled a solid 1800# of cast iron I6 engine, trans and differential and replaced them with the corvette stuff. Between the drivetrain and the suspension swap, I think the 53 sits in the ballpark of 2600# (maybe less, it feels light and highly sprung on the stock corvette springs).

I don't know what sort of power I need to get to the feel I'm looking for. I want it to really thump me in the back when I roll into it. That's why I was focusing on the torque and my component selection was favoring low end power. I have plenty of clearance for a bigger intake; I've got a good foot between the top of the TPI and the hood as it is now, so I could easily fit the stealthram or even a full tunnel ram intake. Most any intake will make more power up top, but not really do more down low. What I'd really like is an EFI twin screw supercharger with a built in intercooler, but the units they used to sell have been discontinued. I'd have to fabricate my own intake to bolt a generic lysholm unit to (not out of the question, just a lot of effort and development). All the love is given to carbs(traditional hotrodder) or the LS platform these days.

I was also thinking about re-gearing to 4.10 or similar, since the trans has such a deep 6th, cruising at 80 would still only be ~2400rpm. Re-gearing doesn't do a whole lot though, I can simulate it by downshifting. The character of the engine remains the same.

cv67

on the right track youre going to want to port the daylights out of the base and find some aftermarket runners (do what you can with those) leave the throttle body alone
assuming you have a 3.45 gear, should be just about right skip the 4.11

are you able to port yourself, can get some good gains if youre patient

thurman_merman

I didn't realize the car was that light to start with. You seem to know what you want and basically how to achieve it so I'm just going to say this: I would start with an intake. Since you have the hood room a stealth ram would be my choice. A super ram would also be good if you can find one. You're on the right track with a smaller cam choice but if you value driveability stick with something designed for a computer controlled vehicle like a comp 262hr-12. Your exhaust should be fine for this kind of power and your stock throttle body and injectors will be fine as well. You can go with heads but I'm sure you know as you open up ports you raise your powerband so if you want to keep it low keep your stock heads. Then you will need a good tune. If you have the means use a tuner over a mail order tune. I don't know what kind of tires you plan on running but if they aren't modern and sticky you're just building a smoke machine as it is, changing the gears is just going to make it worse. That's just my $.02, you should make plenty of power all the way through your cams rev range and be well under your $3k budget.

Churchkey

If your in 6th gear "tipping into it" = close to zero throttle response, 6th gear is 50% over drive you need to downshift to accelerate. 5th gear is 25% overdrive. A rear gear in the low 3's will help.

Also check the ram horn exhaust manifolds they may be restricting the exhaust. 113 aluminum (TPI) Vette heads have a 3/8" raised exhaust port installing early manifolds or the wrong headers will block the top of the port. Stock Vette tube headers are restrictive each tube has 1 square inch of volume @ the collector.

Added: If purchasing headers get them for ZZ4 Chevy heads they have the same exhaust port configuration as Vette 113 aluminum heads.

TPI's begin to suffocate after 4800 rpm change the intake.

j.martynuska

I'd love to see the build log...sounds like a cool build!

eutu1984

You could still yous a supercharger, it would not have an inter cooler and if you want EFI you could always stick a efi throttle body on top. you can get a supercharger like this http://www.jegs.com/i/Weiand/925/650...hoC8mAQAvD_BwE

should fit under your 53 hood.

esp42089

Thanks for all the input. Here's the build log for those interested: http://locostusa.com/forums/viewtopic.php?f=36&t=18148
It's long and there are a lot of pictures. I haven't kept it up to date, but it covers the build well. Because of the crowd here, I need to make a disclosure: the vette REALLY wasn't as nice as it looks in the coupe photos; it had been left out in the sun too long...

I have a 3.45 rear gear. I also am running a Megasquirt 2 and have full control over fuel and timing, so no need to burn chips. I got the GM computer running in the car for a couple days before I burned it up (I think, not sure how, it stopped working entirely), at which point I decided to dive into learning how to control an engine and bought the MS2. My tuning seems pretty decent, but there's a really reputable tuner right near me that I can go to. He wants $800 to fully tune it (dyno and street, said he'd want it for a few days), so I'm waiting until I've got the engine how it's going to be before going that route.

I'm running BFGoodrich G-Force Comp2s in 275-40-17 on the stock rims. It's not super sticky stuff, but it's quite a bit of tire given the light weight.

I looked into an intake setup, but it seems like I'm in $1000 to get anything going (with new fuel rails, distributor, etc.) and almost everything will steal that low end grunt I love with the TPI. I seriously considered a FIRST TPI and it's still not really off the table. I'm also temped to make a sheet metal intake. I've got a TIG and have welded aluminum before, but that wouldn't be cheaper especially with time and effort factored in.

That's a good tip on the rams horns and the exhaust ports. I ground the gaskets and rams horns to match, but I can't say I recall carefully checking the actual match up of the ports to the rams horns. A small lip on the top, due to the primaries sweeping up, would help create an anti-reversion dam but if it's too big, that's just bad.

I've thought, on more than one occasion, that I'd like to try my hand at building a small, low pressure twin-turbo setup for it. Price has kept me out of that realm though cause I'd like to use high quality turbos to get the best response.

esp42089

I'd love to get something like this: https://whipplesuperchargers.com/ind...product_id=223 but for a small block and then stick one of their compressors on top of it. Delicious instant torque with multiport EFI!

ddahlgren

The Eaton ones are pretty good and there are installations with a water to air intercooler. By now I would think there are some on the used or rebuilt market that would be the right size for a 350

ddahlgren

What is the 2k combo to make that much to the wheels?

thurman_merman

https://www.corvetteforum.com/forums...om-an-l98.html

mtwoolford

same as any SBC of similar mileage which doesn't burn oil

drop pan.

roll in new main and rod bearings

new oil pump

new timing chain, new front seal

new cam of your choice, new lifters

then, if the energy / enthusiasm is still there, pull heads and do a valve job.

well, there, that wasn't so hard, writing the reply that is...as to working on the engine, your experience may vary.

thurman_merman

Lol. Ignore this post.

ddahlgren

What does a stock L98 make at the wheels then? I had thought the 250 hp was at the flywheel.

thurman_merman

I don't know. Mine made 225 with a cat back and free mods.

esp42089

If I had to guess, I think mine, as it is now, is probably 200-220whp. It definitely feels like it is entirely done at 4k rpm. The torque can trick you into thinking it's more than it is, but when it's running out of steam so fast, there isn't much horsepower there.

ghoastrider1

rhe AFR heads are a great choice. The 113 Alum. heads are just not that much better than the old double humps. Just lighter. Back in the day, yhe tam horns were yankedto be replaced by headers. the horns were the best ones to have (stock) back in the day. Elerbrock makes a new intake for theTPI, cost around 500 bucks. Do NOT use the TPI from the 305 engines,runners go from bad to worse. The car should push you back in the seat. Rolling at atound 15 mph, my csr will still get side to side with you. Traction is a bitch on the fre times I take it to track during the summer. At rhis rime I only have headers and it runs right at 14 flat, a hair under 100mph. Ahhh, the 53 chevy,,love those things..in fact its what I learned to drive with. I am an old fart. Will have to check out your build site. To bad you don't live closer.. so far, two of us from the forum meet at the drag strip here in Indy on Wensd nites, sometimes both of us race sometimes just one of us. You still have vacuum wipers on that 53? My PC isn't the best and many of the letters are worn away so please forgive the wonky writeing'