1988 Chevy K5 Blazer build - An unorthodox approach

[cRiPpLe_rOoStEr]

Do it, but I guess you would like to match it with a supercharger, which would lead to what is known as Miller cycle. It had been sucessfully done in stationar/industrial and marine engines since the '30s or '40s, and is also used in some cars from Mazda and Nissan.

Originally Posted by dirtydave

Wouldn't a V6 swap get what you are looking for* without all the hard work?

You can also try the mods you're planning into a V6, benefitting from the lesser weight and slightly lesser internal frictions.

[BabyDiesel]

Hondaguy72 - I'll be honest, I had never heard of milling a head before you mentioned it
It does seem like milling would give me the cc's needed for higher compression (0.006" per cc). The forum research I have done has sown that I can delete 5-6 cc's max and bump up my compression by .5 - .75 points. Soooo ---v

355 w/ milled 350 Vortec heads, 59cc, 0.035 quench, piston 0.01" in the hole, 0cc dish - 11.97 CR

355 w/ milled 305 Vortec heads, 52cc, 0.035 quench, piston 0.01" in the hole, 0cc dish - 13.26 CR

Oddly, the super small cc 305 heads put me inline with the Prius's CR.

The 700r4 is staying. I had to drive my mama's Trailblazer with the updated version of the 700r4 in it. I was coasting up to 1/4 mile on flat ground to slight inclines with out losing much speed, much better than my "good aero" ZX2.

Thanks for the info!

[BabyDiesel]

DirtyDave - Glad to see you could stop by, buddy! Yes, these ol' trucks are about as dope as they get and I did consider a 4.3 Vortec V6... with a small turbo Just out of my cost range as of now! Imagine a Atkinson cycle 4.3 S-10 with a quick spooling turbo... I need to stop lol. I have to work with what I have, and good deals!

A tidbit of info: K5s came with straight 6's (4.1 & 4.8). I have to think the oil shortage was the reason for this. An acquaintance told me that he had one and it got, get this... 14 mpg. No better than my TBI 350. Although he was still able to haul a boat down to the beach with it!

[BabyDiesel]

vskid3 - Hot diggidty! Thank you for the thread recommendation! Someone actually mentions Crower's syatem on page 8, and the discussion on valve timing is beneficial to my project.

[BabyDiesel]

Cripple Rooster - I have looked into the supercharger idea beforehand. It just is not in my budget as of now. Well, it could be if I could put a Chevy 3.8 V6 supercharger on my 5.7 What would be the pros/cons of the miller cycle against the Atkinson cycle?

Read DirtyDave's comment for the V6 info. It just insn't viable at this point.

Thanks for the comment, and I will do it

[BabyDiesel]

So I may have encountered a problem earlier today. While researching some things regarding the TBI system, I saw over and over that big cams were not good for the computer.

But whyyyy? The intake reversion caused the MAP sensor to go nuts. With the Atkinson cycle, the efficiency comes from the piston pushing the cylinder mixture back into the intake manifold, a.k.a. intake reversion. So the computer is not going to be able to tell the difference, it seems. I will be contacting Brian Harris @ TBIChips.com and asking for his wisdom. He did my last chip and did an excellent job, his knowledge on these trucks is outstanding. This just might decide the project...

Stay tuned y'all!

[adam728]

Originally Posted by BabyDiesel

A tidbit of info: K5s came with 4.3s in their earlier years (70s). I have to think the oil shortage was the reason for this. An acquaintance told me that he had one and it got, get this... 14 mpg. No better than my TBI 350. Although he was still able to haul a boat down to the beach with it!

Might want to check that fact. The 4.3 V6 didn't come out until 1985.

I will say that their mileage has always proven to be basically no better than the big engines.

[dirtydave]

Is the ride height / tires stock?

What's the plan with that?
High or low looks good either way.

[adam728]

I also meant to ask - what's "blown" about the current engine? I've heard that generic term used to describe everything from a stick lifter to a rod thrown through the block.

And where did 5200 lbs curb weight come from? I always heard they were more in the mid-4000's.

[BabyDiesel]

Adam728 - Thank you for calling out my blunder! I was wrong, it had to be a straight 6. Unless it was swapped, which doesn't make much sense due these peeps being power junkies, not economy-driven like us.

Snap beans, 2 times in a row! I got the weight wrong too! The 5200 lbs. came from my registration card & it being weighted on a scale when I took off scrap metal to the junkyard. It usually weighted 6000+ with a 600 lb. load and trailer. I GROSSLY underestimated that trailers weight! According to ColorodoK5, the curb weight in 1988 was 4676.

You, sir, are awesome in my book for calling my mistakes out

The motor blew like this: Turned a corner. The motor started sounding like a diesel and loosing power. Coasted what I could. Finally got to where I was flooring it and I was loosing speed quick. Looked at the temp. gauge... Over 300 Then it died and I coasted to a stop. I had steam coming out from every mating surface on the block (intake, valve covers, heads, oil pan!), the throttle body, radiator and even the tailpipes. It was quite the catastrophe. Especially since 15 minutes earlier I put over $50 of 93 in it

DirtyDave - Man, I be stuntin' on that 12" of lift and 44" LRR tires Eco-Hick life BO

Na, at the maximum I will run 33" tires on the stock suspension, with an EZ Inch up front is it needs it. I will go with stock height and 31s/15s with the 3.73 gears for the time being, in order to establish a baseline. I do plan on adding 4.10 gears down the road, in order to get the motor in its efficiency range and achieve optimal piston speed (Thank you Frank Lee, regarding OPS).

Might even lower it a couple inches down the road. If I convert to 2WD, then this is probable.