Thread: small block suburban

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Big truck thanks for the suggestion on letting it go. I never was holding a grudge. I was simply being a wise ass just like the orig comment made back; and never was it intended to offend anyone or piss anyone off. It was my wise ass reply that all of a sudden had others on here jump my shit like I did something wrong, and a lot of assumption from veterans were made. If anyone was to go back and look at any of my previous posts, on any thread on here, I was always thankful, appretiative and respectful to those I was asking advice from. Never did I come off like a know it all, and always listened full well knowing there is always something to be learned from the experienced minds on here. Johnny O, Pat Mc and tech inspector have all been people who have previously helped me out, and again always appretiated their input. Looking at my original post nowhere was I being wise or looking to start any shit. If my joking back and being a wise ass back with veterans on here is my being disrespectful, or pisses them off, then oh well. If anyone on here wants to joke Im fine with that, but then they should expect it back. If people on here are gonna jump all over my ass when clearly my posts are not intended to offensive, then Im gonna give them shit right back, and again its not personal as I have never met anyone on here or know anyone well enough to pass judgement... but, I am nobodys victim. If my sticking up for myself whether is be joking back or it turns to insults is gonna cause this backlash from veterans then so be it, as Im not going to take somebodys shit cause Im rather new, and they are a regular. Again though thanks for the recomendation.

Camaro fever and Main cap thanks again for the stroker recomendation. It is something I have researched quite a bit. I think any stroker crank is gonna require some extra machine work to clear the rods at the bottom of the cylinders. Although the cost difference is not excessive, my truck did and does just fine pulling from idle to 3000 rpm, therefore although I would never complain about more bottom end, my problem is mid range power. I am overall happy with the displacement...I think the motor was just built relatively weak from the factory in the overall power department. I think bringing up my compression to around 9:1 vs the stock 8.5, cleaning up the exhaust and intake runners and in the bowls of the heads, new SS valves, new springs and rockers, and an RV type truck cam coupled with some headers is gonna do the trick as others have suggested. Again piston type matierial I am very open to suggestion (is it worth going to a hypereutectic, and or maybe forged any benefit?) Finally again I already have a 3" high flow cat and cat back exhaust, but would really love to do a true dual bolt on system if anyone knows of a manufacturer. If I had access to a pipe bender Id do a custom sytem myself, but is not an option. In addition if anyone has any suggestions for upgrades on the trans rebuild to make it more stout I welcome them. The trans on my truck has never been rebuilt, and although shows no sign of blowing at a well maintained 230K I cant help but think its days are numbered, especially behind a fresh motor...while the motor is out I may tackle that job as well.

IMO the hypereutectics are well worth the extra money. The clearances are different for piston to wall clearance, might want to make sure your machinist is aware of this. I put a set of the Keith Black pistons in an engine a few years back, they are still working great. If you upgrade to the hypereutectic pistons, might want to consider the good zero gap second ring too, cost a bit more but well worth the expense IMO.

Dual cats and big exhaust is definitely the way to go, definitely frees up the exhaust. Before you tie up a bunch of money in your heads, might want to consider a set of Vortec heads, others have said they make great low end torque.

As far as the cam, I usually fill out one of the tech sheets for the cam company and go with their recomendation. I use Comp Cams, but I'm sure the other companies offer the same service.

For just a few more bucks while you have everything apart, might want to consider balancing the rotating assembly. Then of course a quality timing chain and gears, oil pump, etc. should all be part of the build. Roller rockers are also a good investment on any engine, they reduce friction and free up a few more ponies.

After all those miles, a good radiator clean and inspection, along with a high flow water pump and thermostat would also be in order.

Thank you for the suggestions.

later!

geeze we're a happy crowd

Originally posted by firebird45331
geeze we're a happy crowd

hard to get a hug around here.

1. Port the stock heads. Reasons why appear here. Keep the stock valve size, but make sure they are backcut.

2. If you want to go with a roller lifter then get the entire set from a junkyard Caprice/Roadmaster/OldsCustomCruiser wagon, in any year from 1989-1996. I say wagon because they are probably well maintained; any other TBI v8 car will also have the same roller lifters but more questionable maintenance.... especially a copcar Caprice.

3. If you stay with flat tappet, I suppose you could use a new cam but I would not stray much from the stock specs, because you will gain a lot from the head porting so you don't need a hotter cam. Especially if part throttle performance, and towing, are important to you.

4. If you go with roller lifters, use the 1994-1996 Caprice LT1 camshaft; this is also the one used in 1996-1999 Vortec L31 engines. It's perfect for a truck application, and it was good enough with the iron LT1 to make 260 fwhp and 330 fw ftlbs.

5. Keep the TBI. Port the intake manifold, especially the lower plenum runners (lower plenum don't flow as well as the upper).

6. Try to add the best dual exhaust + low restriction cats you can find. This coupled with an engine that breathes really well will make an awesome street/towing performer.

7. Make your own ducted cold air filter. See this thread for ideas:

http://impalassforum.com/cgi-bin/ult...c;f=9;t=001945

See this thread for general info on TBI engine mods/maintenance:

http://impalassforum.com/cgi-bin/ult...;f=33;t=009021

FYI, your existing LO5 engine was rated at approx 210 fwhp and 300 ftlbs. You should be looking at 270-280 fwhp and 350+ fw ftlbs if you do the above. HTH.

First of all, a great hug to everybody who reads this thread. (seems to be the way to start a reply on this thread )

OK, back to you engine problem:

I would get some good heads and aim for 64cc chambers, and around 180 cc intake runner volume. Make sure to get good flowing 180s, like Dart or World. Or stay with GM parts and go either Vortec (you will need a new intake manifold to fit the different bolt pattern), which are the best flowing GM-produced heads in that category, or if you want to stay non-Vortec go with 041/186/492 style GM heads. They're very good for truck use. Whatever you do, stay iron.

Go for as many rollers as your money will buy. Best bet is hydraulic roller cam kit and roller rockers. Reducing friction is ALWAYS a good idea. Then you can go a little higher on the compression, which brings your efficiency up. Try to stay under 10:1 static CR, aim for like 9.4-9.7 : 1. To do so get flat top hypereutectic pistons. In my opinion there's no justification at all anymore for non-hyper. Hypers are very cheap and last almost for ever. They expand less that non-hyper or forged pistons when they get hot, so they can be run on tighter clearances and the rings will make a better seal (corrected this one, Erik ). Forged won't get you any further improvements in a street engine, but they will cost much more.
Check all clearances before you go to the machine shop. Chances are the crank won't need grinding at all yet, so you can save some money. Polishing the journals might be enough. Just the same with the block, maybe it doesn't need flattening, but reboring and honing will turn out to be necessary. Flat tops get better squish, which improves the burning process and lays off detonation, so you can in 98% of cases go to 10:1 before detonation. Stay safely under that and stay on pump gas. This way you should be OK.
The reason I say go for roller is this: A roller cam creates a larger area under the valve-lift-curve, which means it lets in more mixture without the need for fast-wearing high lift rockers and stiffer springs. It also compensates for the short duration which you want to create torque low down. I'm just building a 350 (bored to 360) for my G20 van, which is weightwise similar and also my driving needs are similar to yours.
This will be my setup:
492 GM heads (recond, bronze guides, 2.02/1.60 valves, backcut, chamber deshrouded and bowl hogged, large valves only because I happened to get hold of the heads like this)
Crane hydraulic roller cam XR258HR-10 SBC (wont fit your application, because your block is newer, but you could aim for something similar)
stock 4 bolt block
probably KB or similar pistons, flat top with 2 reliefs (4 reliefs would disturb the quench area a bit)
Intake is a Edelbrock performer (not RPM) with a Edelbrock 600 cfm carb (this is where your system differs greatly from mine, which might well affect your choice of camshaft, if you want to stick with the TBI (call comp, crane etc. for their advice on cams). The TBI will compensate for heads with little swirl and you can get chips to change the mixture per RPM, flow-wise you will be similar)
Trans is also a 700, with B&M clutches and Kevlar band, lower oil pan and extra cooler, also I installed a shift kit to keep the clutch pressure in low RPMs up and a 13 vane rotor to even pump flow. Along with a beast sun gear shell and new steels this trans rebuild cost me well under 400 bucks and is easily strong enough for the weight of my van. (When you rebuil a trans make sure to put the chekc balls in the right places and to tune your trans to the vehicle weight! Then even a 700 will last for ever).
And yes: building a stroker will get you more torque, but it might invalidate your emissions test and it is a bit of a problem for a first time builder. I wouldn't do it, but that's just my opinion.
For Exhaust I have full length headers (not shortys), from then on 2.5 inch dual exhaust (with H-Pipe, no cat, though). I built it myself from 2.5 inch stainless piping I found at my local scrap yard, when a factory near here was wrecking its cooling system. Hardly cost anything and I could cut out all the bends and straight bits I needed and only had to weld them together. Works fine, lasts for ever and even looks good if you run over it with a power-brush.
That should get you a little more torque across the whole RPM-band and shift useable RPMS up the line a bit for passing and "fun". But don't expect to run higher than 5000 RPM on this engine.
Hope i could help you, good luck for your project
Mad

Thanks for all the replies and suggestions. By the way for those who mentioned emissions...there is no inspection and/or emissions testing in Florida.