Hello!

I need some help to find out what would be the best...

I have a stock LG4 305 engine in a 1984 Z28-E Camaro. I am planning to change the engine to a 350 next year, but till then I decided to do a small refresh on the old one.
This engine has around 200.000 km in it and has lost a lot power during the years.
I bought a 1405 for it with a 7101 intake, and a 10550 melling pump, a new dui dist, that I plan to use on the 350 as well.

I also have a 7102 cam with lifters that i dont want to keep for the next project, and if I would like to put it in to this engine, should I change the valve springs or stuff like that or it will work without and what effects should I expect? Will it improve anything or it will be weaker than before and I should leave it as it is for this one year period?


Thanks in advance!

P.S.:Sorry about my english...

 

any suggestion?

 

is the 1405 a Edelbrock carb number? theres a lot more to ditching the qjet then changing carbs. Do some research on that before you decide to do it.

What's the exhaust? I worked up what you were wanting to do using stock manifolds with the cam and parts listed on DD2000 and it doesn't make 200hp at the crank, and the power is coming in late. It's basically making the same as stock but at a higher RPM. It's 188fwhp @ 5500rpm, while a L69 cam makes peak hp 188fwhp @ 4000rpm. Over lap is terrible too, so all you're really getting a rough running engine that makes power late and uses too much fuel.

If you have headers and decent exhaust it's much different though. It's estimating 247fwhp @ 5500 with everything you mentioned. It's still going to run rough, theres much better cams out there for your LG4 but it will work if you just want to have the fun of installing it.

 

You need headers and exhaust before anything else. The 7102 cam is WAY too big for your LG4. I think DOOM confused it with the 2102.

 

I was using that cam's profile but I don't think I emphasized enough on how badly it would run. It honestly has the most overlap I've ever noticed with any cam I've tried messing around with DD2000 and a 305ci SBC. I'm sure there's worse but it is down right terrible.

 

Thank You for the answer!

I have to change the carb because the previous owner of the car has modified the qjet for autogas and has drilled some holes in it and now it isn't functional.

I'm planning to use hedman longtubes ending in a dual exhaust with cherry bombs.

It is an edelprock performer RPM intake and the same camshaft. I bought them together really cheap, and I have no further plans with the cam that's why I want to use it if possible and on the other hand the old camshaft I think has round lobes after so much km-s. I also have some comp cams high energy pushrods that came with the cam and intake. And I can widen the intake ports on the heads to match the intake and also the exhaust ports to match the headers for a few hps.

Does the new info changed your opinion?

 

I can't recommend using this cam at all. Listen to Attila, guys like him are way more experienced then my self spinning wrenches.

Just comparing the different setups in DD2000 you are loosing an estimated 50 ft/lbs peak torque if you were to install this RPM cam, and the factory cam makes it much earlier. In fact you would need to stall at 4300rpm's to have even close to the same power from a stop, and even then it's off by over 50ft/lbs.

The stock heads can't handle the lift of the RPM camshaft and would need machined too accommodate.

If you are just wanting to install a cam i would set this one aside and look for another deal. Something like comp cams xe256, or xe262, is as aggressive as I would go with your current setup.

 

All right, then I'll try to sell the cam here in Hungary, hope that someone has the right setup for it.

Thank you all for your help!

 

If what you need is a cheap cam & lifters to get your motor screwed together and running well, look at the Summit house brand cams. The SUM-K1102 is an exact clone of the Edelbrock Performer cam (base model Performer cam, not the RPM cam) and it real mild- one nothch over a "stock" cam (still has 20* more duration than the original LG4 "peanut" cam, though!!). It'll work with stock springs if you keep RPMs below 5500 and it won't run your heads beyond their lift limits.

Price: $90 INCLUDING LIFTERS. It don't get no better than that for new parts.

It's a quality piece that will last a good long time even though the lobe designs are older and can't quite compare to the newer computer designed cams like the popular Comp XE series. (The mild lobe designs are actually what allow it to work with stock springs so well.)

If you're feeling adventurous you could go up one notch above that to the SUM-K1103. It's basically similar to above but with 10* more duration and a little more lift. Again, it'll work with stock springs in stock heads if you keep it below 5500. But I'd really recommend stepping up to at least a set of cheap "Z28 springs" like you find on eBay and places like that for under $40. They're drop-in replacements for stock and require no machining work on the heads at all to use them.