drcook

I was following the 377 vs 383 thread, which triggered me to do some lookups on the web. During those lookups I ran into a mention of a World Products Motown LS Iron Block. Which is a block that allows you to use Gen 1 SBC internals, bellhousing etc and mate them up to LS heads and intakes. This opens up the thought of ALL kinds of modifications for the C4's prior to the LT1/Optispark engines.

While the builds can add up, imagine the surprise on the late model Corvette owner's face when you run away from him with your lowly C4. Granted brake upgrades, chassis stiffening and such will have to be done, but to put the C4 into the future ....

Here are some resources I found while searching. Take note the block is available in different bore sizes and can be opened up to a maximum 4.200 in.

https://www.summitracing.com/oh/part...4080/overview/

https://www.onallcylinders.com/2017/...-block-part-1/

https://www.onallcylinders.com/2017/...-block-part-2/

Go down to page 5

http://www.pbm-erson.com/UserFiles/D...eb-version.pdf

FAUEE

At that point why not just ls swap?

ChumpVette

drcook

From what I saw, it is for folks that have an investment in Gen1 internals. I could see advantages to it, there must be folks buying them or they would drop them from the lineup.

One advantage is that it says you use LS intakes if so then ability to use the superchargers from the LS series of motors AND you already have an investment in internals would be a plus.

I simply thought it was interesting and an alternative not a recommendation.

Evidently some folks like the C4 platform.

One application I can immediately think of is that Optima's Search for the Ultimate Street Car. There is a class for 1989 and older. This would put a 1989 C4 right up there and make the C4 truly a top competitive machine.

In the 1990 and newer class, the C4 doesn't have a prayer. Not when it is going up against the newer Vettes and Vipers that have lots of money spent on making them even better than what they are to begin with.

cv67

Think its a great idea, some awesome heads are out for the LSx these days plus the user doesnt need to change every single thing under the hood.
Not exactly cheap to do a proper ls conversion

383vett

jayjones

Does it use the smaller cam core diameter of SBC?

drcook

this is wrong. I was looking at it when tired. for the hybrid block on page 8 of the PDF, it says 55 mm (55 x .03937 = 2.165)

Kevova

Last time I checked just the block was 3500. IDK it seems cost prohibitive for the average C4.

drcook

Summit has it priced at $2459.79. Expensive, yes. For the average person/C4, yes I agree. But for certain applications, no.

ghoastrider1

sounds interesting.

MatthewMiller

FWIW, a C4 dominated this GTV class in the two Optima events it attended. The owner/driver is Chris Ramey, aka "theseal" on this forum. His is equipped with a built LS engine, but it uses stock suspension locations, stock frame and subframe, etc. IOW, not a race car masquerading as a street car, but a legit production C4 with a badass motor and fat tires. He won GTV at the NOLA event, and put an unholy ***-whoopin' on the class in all the timed events at the Vegas finale. The only reason he didn't win Vegas was that they killed him in the D&E portion, and because of the way they score your points for the timed portions (you are compared to everyone's time, not just those in your class). The point being, drcook is right that unless/until they change the class rules to boot out the C4, it is easily the car to run in GTV.

C409

….. How can it be a "legit production C4" if it has an LS engine ? …..

MatthewMiller

I didn't mean "showroom stock." I just meant that it's not a tube frame race chassis with a C4-looking body on it. It's actually a production C4 with mods (obviously the drivetrain is a biiiig mod!). The rules of some of these pro-street-based classes are incredibly open, and it's possible to bring a thinly disguised race car (if you can tack a VIN tag to it and trick a shop into inspecting it). For an example of that, look up Mike Dusold's "1967 Camaro," which has not one single OE part on it except the VIN tag.

drcook

If I had the money to build a GTV class car, I would use that engine above and a lot of the knowledge I have learned on this forum to build a killer car. From Tom's discussions on frame flexibility and analysis on his cart, I think that the car can really be stiffened up, in addition to the addition of the roll cage.

Now keep in mind people have LOTS of money in a lot of those cars so to build the ultimate GTV car is going to cost. So with that said, I would get a good metal fabrication shop to help me cut out the floor (in a manner that it can be put back in) and fab up the structure like Chevy/GM employed in the C5's along with fabbing the metal strips to turn it into a fixed roof coupe. The fabbed floor structure would follow the contours of the oem floor so it could be put back in. This would really help with what Tom described as it seemed as the frame was "walking".

The other mod would be the same as GM did to test their concepts of the C5 out when they modded up a C4 would be to fab up and make a real torque tube.

Yes I know this is in essence, building a C5, but it keeps it in the 89 and older class while benefiting from what GM found out.

Then the Brembo or other better brake upgrade and larger rims to clear of course. Coil overs like so many of you on the forum have done, with the upper mounts reinforced like was shown here on the forum.

That engine block and some of the add-ons that company makes, like the adapter plates that bolt to the LS heads and allow SBC components to be attached, with all the benefits that the LS heads allow. Being slick like this should, I repeat should help out in the D&E class.

But the caveat as I said, is the expenditure. A person has to have a goal, and the wherewithal, and the willingness to do this on a C4 instead of just going to a more modern Vette or Viper platform.

I read current and all posts and I know that there is enough cumulative knowledge AND SKILL on this forum (the C4 forum) to win that competition in the GTV class using a 1989 C4 as the car to start with.

That skill would include a driver (I am an old crippled guy, really) and due to my orthopedic issues could not ever hope to compete as a driver, but there are some of you here that can.

ALL the above is conjecture of course but I think it really could be done and is NOT THAT pie in the sky crap that he who must not be mentioned 3 times in a row was spouting off.

drcook

I was looking at that one this morning, and this statement is so true. That runs in the GTL class

https://www.lsxmag.com/features/car-...uring-monster/

https://www.optimabatteries.com/en-u...a-invitational

http://driveusca.com/class-descriptions/

this is one of the machines the above would be competing against

https://www.optimabatteries.com/en-u...-ousci-preview

cv67

One badazz Camaro also. Those ZL1s are no joke

Mike Holmen

Why not just use the LS7 block and heads. You can find a decent engine cheaper than the World Block that your suggesting, and ts aluminum piece. 4.25 inch bore.

These days you could build an aluminum RHS LS engine around 512 cubic inch size. Of course its going to be pricey. I'm not sure what your going to gain going with the gen 1 internals vs. the LS internals. The LS stuff has come down a bunch in price to where a average guy could build a pretty decent engine without breaking the bank.

drcook

Basically if you go read about the block instead of just assuming I am recommending it, you will see that is was designed for people who already had a substantial investment in Gen 1 SBC internals.

It was also something different to discuss. There must be a market for it, otherwise they wouldn't be manufacturing it.

Out on eBay the LS7's are $10,000 and more. A drop out is $12,000. Then all the expense to fit that engine into a car never designed for it. You may as well invest that kind of money to upgrade to a newer Corvette.

Just an LS7 block is $3000.00 for a used one on eBay. That is the bare block. Then you have to buy the rest of the stuff.

So for someone that already has a good crank,rods pistons and pretty much wants a drop in engine (still have to do electronics) but drop in using the same motor mounts, the same flywheel/manual trans/flexplate/auto trans plus the adapters that company sells that allows SBC components (alternator, etc) to be bolted to the front of the LS heads, it is not too bad a deal. They also get the breathing of the LS head design and intakes.

MatthewMiller

It's not really germane to the topic, but just a technical clarification: That's the tall-deck version of the RHS block, and that probably won't fit under the hood of a C4 without major surgery. I believe the biggest standard-deck LS engines being built right now are 468 (maybe 472).