Engine building decisions/advice (intake, cam, ignition)

[MaineShark]

With quite a bit of help from Brian (AKRAY4PLAY), I've gotten some of the basics of my new engine sorted out.

So far, I'm looking at a 400 block, bored 30-over. That gives me 406 cubes. With 5.7 rods, 64cc Trick Flow heads, and 18cc dish Keith Black pistons (0.010 in the hole), that's just shy of 10:1 compression, depending on the exact thickness of the head gasket.

That's the basic stuff, and the most "scientific." Now comes the "art" side of engine building: I need to get the air in, get the valves moving, and get the plugs firing.

In reverse order:

Can I use my stock ignition? Or do I need something fancier?

Anyone have any cam recommendations? I was browsing catalogs, and the Comp Cams XE262H or XE268H look sort of like what's been recommended to me (by Brian and others), but I'm not exactly a cam expert, by any stretch of the imagination, so any advice would be appreciated. I'm looking for torque, of course

What sort of intakes should I be looking at? Hood clearance seems to be an issue (and I'm not replacing my hood), so any insight from people who know what will fit would help out greatly.

Joe

 

[Bob_K]

I'm not an engine builder but have been doing research for about the last 3 to 4 months so that I can get my set up right the first time. Knowing that, take the following recommendations with a grain of salt A lot of your question can't be answered without more info. Do you want to be 50 state legal? If you want to be legal I'd go with one of the Crane Powermax emissions legal cams. Depending on what balance you want between power and torque (not to mention rear gearing to help determine RPM band) you could go with the CRN-114112 at the torque side of the spectrum, or the CRN-114142 at the HP side. They also make a 122 and 132 for a nice middle ground. As far as ignition goes, I'd probably upgrade to a MSD system. I don't have one (yet) but everyone I know that has them says they really do add power and gas mileage as advertised. If you're keeping your Q-jet I'd suggest the Weiand Action Plus intake, it has a larger power range than the Edelbrocks (Advertised at idle-6000 RPM) or if you're goinf square bore carb the Weiand Stealth (idle-7000 RPM). Both of those manifolds should cover about any RPM band you want, and leave room to add more cam later. Hope that helped a little.

 

[1979toy]

Take a look at the information on this site and download the compression ratio calculator. http://members.uia.net/pkelley2/DynamicCR.html
When you have run your engine through the program you are going to find that you want a cam of about 274 degrees of intake duration at a minimum, more likely in the 280 to 290 duration range. Look for a cam with 112 or 114 lobe centers unless you are willing to put up with a lope at idle.
Without replacing your hood you are limited to a very few intakes that will work. I would recommend an Edelbrook Performer.
You stock ignition will work fine. You may want to have the distributor rebuilt or replaced with a rebuilt distributor as long as you've got it out.
Good luck with it.

 

[MaineShark]

Emissions legal? What's that? I'm not exactly worried about it, since we ain't got sniffer tests here, and there's no way they can know what cam I have, when the do the safety inspection. Plus, no one even enforces those rules, anyway.

I have 3.55:1 rear gears and a TH350...

Thanks for the thoughts.

I'll check out that link, Steve.

Joe

 

[Jack]

http://www.camcraftcams.com/

not cheap ... you'll get personalized service ... lotta teams run these cams but do not tell. I have first-hand experience ... they're good! BTW, they have a couple sets of very nice 5.7" & 6" H-beam rods left at decent price.
JACK:gap

 

[LEEJANDZ]

Can I use my stock ignition? Or do I need something fancier?

Anyone have any cam recommendations? I was browsing catalogs, and the Comp Cams XE262H or XE268H... [/B]

Get the MSD 6AL box w/ MAGNECOR wires.
As far as the cams... both of those are the "nitrous" cams.
Have you asked any of the guys at COMP CAMS.

Try Michael Douglas he has helped me out

I will follow your build closely as I too have a 79 L-82.
But I will stick with my 350 CID for now.



JASON *** BRAND NEW MAGNECOR WIRES FOR SALE!!! *** 1979 L-82

 

[cruisin-davey-g]

With quite a bit of help from Brian (AKRAY4PLAY), I've gotten some of the basics of my new engine sorted out.

So far, I'm looking at a 400 block, bored 30-over. That gives me 406 cubes. With 5.7 rods, 64cc Trick Flow heads, and 18cc dish Keith Black pistons (0.010 in the hole), that's just shy of 10:1 compression, depending on the exact thickness of the head gasket.

That's the basic stuff, and the most "scientific." Now comes the "art" side of engine building: I need to get the air in, get the valves moving, and get the plugs firing.

In reverse order:

Can I use my stock ignition? Or do I need something fancier?

Anyone have any cam recommendations? I was browsing catalogs, and the Comp Cams XE262H or XE268H look sort of like what's been recommended to me (by Brian and others), but I'm not exactly a cam expert, by any stretch of the imagination, so any advice would be appreciated. I'm looking for torque, of course

What sort of intakes should I be looking at? Hood clearance seems to be an issue (and I'm not replacing my hood), so any insight from people who know what will fit would help out greatly.

Joe

Joe: Two Words.........Roller Cam (can get a higher lift & more duration without killing the motor; less friction; & more horses.

 

[MaineShark]

True, but roller conversion kits are a bit more expensive than I want to spend on this motor. Now, roller rockers, on the other hand, are a near certainty.

Joe

 

[cruisin-davey-g]

True, but roller conversion kits are a bit more expensive than I want to spend on this motor. Now, roller rockers, on the other hand, are a near certainty.

Joe

Hi Joe: OK on that on..............Didn't know how much you were willing to spend. One thing I forgot to mention: If you're using the trick flow heads, make sure you index the spark plugs in the heads. You'll get a little more out of the heads doing that to "trick flows". Also, if you're beefing up you ignition system with a MSD unit, don't use "split-fire" plugs. The MSD will wreck havoc on those plugs. And maybe put a gear drive in also. Sounds like you're on your way to a "screamer" Vette! Good luck!

Dave

 

[MaineShark]

Yeah, inexpensive is key

It amuses me that I'll probably spend less on performance mods, than a lot of folks do on body kits. Makes stomping on them a bit more fun

I've changed the plan a bit: only putting the pistons 0.005 in the hole, which will bump my compression to just a hair over 10:1.

I'm also going to put in a new tranny: 200-4R, with either 3.73 or 3.90 rear gears. That should make things a bit more interesting, and keep the revs down on the highway.

Joe

 

[cruisin-davey-g]

Yeah, inexpensive is key

It amuses me that I'll probably spend less on performance mods, than a lot of folks do on body kits. Makes stomping on them a bit more fun

I've changed the plan a bit: only putting the pistons 0.005 in the hole, which will bump my compression to just a hair over 10:1.

I'm also going to put in a new tranny: 200-4R, with either 3.73 or 3.90 rear gears. That should make things a bit more interesting, and keep the revs down on the highway.

Joe

Joe: Isn't the 200-4R the trans which was used behind all of the Grand Nationals?

 

[MaineShark]

I'm not overly familiar with the Grand Nationals. I'm 99% certain that it was at least used on some of them.

I like it because the lower OD gear lets me run a more agressive rear ratio (3.90), which gives me almost the same first gear as the 700-R4, and much better second and third, while only running 100 rpm hotter on the highway, than with the 700-R4 and 3.55 rear.

And, it allows full-throttle upshifts.

Plus, it bolts-in more readily (no custom crossmember, no driveshaft shortening), so I can spend the money I save on the rear gear swap, giving me the same price, but a brank-spankin'-new rear gear.

Joe

 

[cruisin-davey-g]

I'm not overly familiar with the Grand Nationals. I'm 99% certain that it was at least used on some of them.

I like it because the lower OD gear lets me run a more agressive rear ratio (3.90), which gives me almost the same first gear as the 700-R4, and much better second and third, while only running 100 rpm hotter on the highway, than with the 700-R4 and 3.55 rear.

And, it allows full-throttle upshifts.

Plus, it bolts-in more readily (no custom crossmember, no driveshaft shortening), so I can spend the money I save on the rear gear swap, giving me the same price, but a brank-spankin'-new rear gear.

Joe

Hey, Joe: I'm just curious. I heard or read (can't remember which) that those 200-4R's that were behind the grand Nationals could hold up to the horsepower, but not to high torquing motors. I know that the grand national's little "4 banger" produced alot of horsepower, but not much torque. Anyway, I read (or heard) that if you put one of these 200-4R's behind a high torque motor, the front pump in the trans wouldn't hold up. Any comments about this?

Dave

 

[vets4-2]

Hey, Joe: I'm just curious. I heard or read (can't remember which) that those 200-4R's that were behind the grand Nationals could hold up to the horsepower, but not to high torquing motors. I know that the grand national's little "4 banger" produced alot of horsepower, but not much torque. Anyway, I read (or heard) that if you put one of these 200-4R's behind a high torque motor, the front pump in the trans wouldn't hold up. Any comments about this?

Dave

were did you see a 4 cyl grand national??????????? I know I'm stuid but 3.8l in 4 cyl:confused

 

[vets4-2]

With quite a bit of help from Brian (AKRAY4PLAY), I've gotten some of the basics of my new engine sorted out.

So far, I'm looking at a 400 block, bored 30-over. That gives me 406 cubes. With 5.7 rods, 64cc Trick Flow heads, and 18cc dish Keith Black pistons (0.010 in the hole), that's just shy of 10:1 compression, depending on the exact thickness of the head gasket.

That's the basic stuff, and the most "scientific." Now comes the "art" side of engine building: I need to get the air in, get the valves moving, and get the plugs firing.

In reverse order:

Can I use my stock ignition? Or do I need something fancier?

Anyone have any cam recommendations? I was browsing catalogs, and the Comp Cams XE262H or XE268H look sort of like what's been recommended to me (by Brian and others), but I'm not exactly a cam expert, by any stretch of the imagination, so any advice would be appreciated. I'm looking for torque, of course

What sort of intakes should I be looking at? Hood clearance seems to be an issue (and I'm not replacing my hood), so any insight from people who know what will fit would help out greatly.

Joe

what does .010 in the hole mean??:eyerole :eyerole Do you mean your pistons are .010 below the deck surface? If that's what yur talking about that's called the comp.hgt.of the piston PS. who's making these pistons? If It's J&E I can get you a deal. Just give me the dia. land size weight type & size of pin disired cr a the correct height for the rod type of head lift of cam ramp size & rate rocker ratio and I bet I can save you a little

 

[vets4-2]

These are just a couple other things I'd get MSD 7800 $680. For all that comp. you'll need this starter "power starter" #2785 $250. for your intake sys. holley #hly91503201 $2300. B/G fuel pump $500. At least that way when you hit the gas and your car goes you can tell your friends "BUT I BOUGHT THE BEST"! best of luck!

 

[MaineShark]

Re: Re: Engine building decisions/advice (intake, cam, ignition)

Hey, Joe: I'm just curious. I heard or read (can't remember which) that those 200-4R's that were behind the grand Nationals could hold up to the horsepower, but not to high torquing motors. I know that the grand national's little "4 banger" produced alot of horsepower, but not much torque. Anyway, I read (or heard) that if you put one of these 200-4R's behind a high torque motor, the front pump in the trans wouldn't hold up. Any comments about this?

I'm not planning on a stock tranny The guys over at Bowtie Overdrives say it won't be a problem to build something that will take the power. Not being a tranny expert, I'm inclined to trust their judgement

what does .010 in the hole mean??:eyerole :eyerole Do you mean your pistons are .010 below the deck surface?

Yes, that's generally what that term means.

If that's what yur talking about that's called the comp.hgt.of the piston

Actually, compression height refers to the distance from the top of the piston to the center of the wrist pin. It is most often used to determine deck clearance: add the compression height and the rod length to half of the stroke, and compare to the deck height. The difference is the deck clearance.

PS. who's making these pistons? If It's J&E I can get you a deal. Just give me the dia. land size weight type & size of pin disired cr a the correct height for the rod type of head lift of cam ramp size & rate rocker ratio and I bet I can save you a little

As you quoted me saying, they are Keith Black pistons.

Joe

 

[Rob]

Offshoreperformance.....you're now starting to **** me off. You're out of here. I'm banning your IP address. You try registering here one more time, and I'm going to having a little chat with your Internet Service Provider.

I know what two ISPs you've used to connect with and if my suspicions are correct and you work for the company that I think you do - I will contact them as well if I have to.

Say buh-bye.....

 

[cruisin-davey-g]

were did you see a 4 cyl grand national??????????? I know I'm stuid but 3.8l in 4 cyl:confused

Whoops! That was a "typo". So, don't stay too confused! Sorry 'bout that!

Dave (I musta got run over by that "4 Banger" GN!)