Avernus

I know a lot of people on here ask these questions all the time and I have done my fair share of surfing/searching the boards with minor victories.

I'm going to be taking out my 88' 350 SBC and boring it out .030 over. A while ago I was confused about what all this means, but since then I have spent many hours reading and learning. I would say that I would be able to hold a very competent conversation with someone about the way boring/stroking goes on in an engine. The reason for saying all this is so that you all understand that I am serious about doing this and am not just another 'just for information person'.

So My question now is What do I need? I know I need the kit. I am thinking about the fourth kit down on this site:
http://www.strokerkits.com/350_sbc.htm
I would be getting Option C.

As far as Cam selection I am a little bit confused. I think I'm going to need something in the 220-230 @ 50 Duration range with 114 LSA. Would this be good for a TPI car? Any cam recommendations for making power in the 3000 RPM range are appreciated (please speak from experience). Another of my main concerns is that I want it to sound really good.

Another concern is the computer. If I have done my research correctly then there should be no need to reprogram anything except the timing. I.e. I won't need a different PROM chip. Please confirm or correct me on this.

For the final concern I would like to admit that I have never done anything like this. I took apart an engine once to learn about how it all worked, but nothing like this. So i'm sure there is plenty that I haven't thought about getting that I will need. A full list of what needs to be changed/ replaced/ modified would be absolutely amazing, however I know that is a daunting task. If anyone is up for that I would be very greatfull. If you all could please post some things That I will probably miss/ not expect.

Thanks so much

P.S. The build is scheduled to get underway on July 8th. That is when all the parts will be ordered so this is a moderately urgent ask for help. Thanks again and there will be many pictures and comments on the build as it takes place.

-Nathan O'Kane

Ozz1967

iTrader: (4)

For the engine work itself, since I just had a block built, personally, would take the block to a machine shop. They've got all the milling tools and calipers and everythign else you'll need. Plus if they screw it up they have to fix it...or replace it. Once you know if .030 is enough to clean up the cylinders (I was forced to go .040 on my 350 build) you can get the pistons to match it. More than likely .030 will be fine.

If you don't want to stroke it, then you can probably re-use your crank and rods, just have the machine shop check them for tolerances to make sure you don't have to grind (resize) them. Sometimes shops will want to do it anyway just to make sure all is well.

As far as the rest of it, you'll just need a standard rebuild kit, just specify the bore size so they know what you're getting it for. The rest of the stuff you can use from your old motor though it's up to you if you want to get new bolts for everything or not. You shouldn't have to touch the ECM...355 is barely more than 350 so I can't see where it would make any difference unless you're really into tuning your ECM.

Cams aren't my specialty, I spent 3-4 hours on the phone with the techs at Comp Cams, lunati, and Crane discussing my engine build before settling on a cam. Now, if you want it to "sound" good, and perform, I've heard good things about the Comp Cams "Thumper" line. I personally liked what I saw and read about the "voodoo" line from Lunati. Anyway, I hope this helps!

Apeiron

Why?

Avernus

OZZ: I am doing the work with my cousin who works in a machine shop so he and I are going to be doing all the work. He does this on the daily so he'll know best, but I, myself want to be able to contribute to the completion of the project as much as possible. So thats the whole machine shop thing.

I would like to stroke it too, but I don't think that is going to be in the budget this time. Maybe a little later, but for now I don't want to go too extreme.

As far as the cam goes, it's good to hear that the guys at luni will be willing to talk with my for that long about my build. If you don't mind how much did your cam end up costing? I'm definately going to look into the thumper cam. The name alone sounds like what I want.

Apeiron: Unfortunately forums are very bad at expressing 'tone' esspecially with so little to work with. However, With what little you gave me your questioning my motives for building my engine. Going against my doubts and trying to stay friendly I will tell you WHY I am doing this.

My car has ~230,000 miles on it. I would like to freshen it up while I have the opportunity to work with my cousin and learn something a long the way.

Is this good enough for you?

Apeiron

That's fine. Most people come in here and start talking about boring an engine as though it's some sort of performance option.

Rather than decide how much you're going to bore it and buying parts now, I'd wait to see what sort of shape the block is in first.

Since you're already getting new pistons, you'd only be spending about $150 more for a new crank to stroke it, too.

Avernus

Correct me if I'm wrong, but then you add the need to have a new PROM chip, bigger injectors and all sorts of other stuff.

five7kid

iTrader: (14)

383 is pretty much a guarantee that none of your TPI hardware is up to the task. That's a bigger issue than PROM tuning.

A Holley Stealth Ram is more than capable of handling the extra displacement. One of the lowest price options available as well.

I agree that no parts should be ordered until the engine is out and has been checked over. If it has received reasonable maintenance, it will probably clean up at .030" over/.010" under, but that isn't a good assumption to make.

(I assume you meant a July 8th project start date)

steve102972

iTrader: (1)

If your going to change cams check out a bunch of different cam manufactures, alot of them today make computer friendly cams for computer controlled cars.When u start getting up in duration around 230 at .050 duration alot of items come into play and your computer isnt going to able to compensate 4 them(idle speed,cruising,wot)stall speed,gear ratio and other factors come into play also to get the best performance out of your set up. It all should be matched to perform together. Start with cleaning up the block and go from there.Try to get the most compression u can get away with on pump fuel usually around 10:1w/iron heads and 11:1w/aluminum but the more u do is going to dictate the more computer mods.U can get away with more or less compression depending on the timing u run.Pretty much though the bigger u make the engine the more air and fuel your going to need so youll have to have the chip modified.

Avernus

Well i can't say how well the engine has been maintained, I mean *knock on wood* it has a ton of miles and it still runs pretty strong. That really doesn't mean anything though. So of course I will yank it and tear it apart before my bank calls to confirm that I am sending X amount of dollars to various parts companies.

What could be wrong that it would need to be bored out more than .030 over? I read about "pinholes" a while back and that came to mind. Is that it?

What do you mean by .010 under? I've never herd under being used in engine speak.

I looked at the Stealth ram and it's around 3k just for that. I'm not willing to shell out 3 grand just for an intake. I hope that you aren't implying that I need one because I might as well scrap the project now.

and yes, july, You> <me

Oh yea I'm going to spend a lot of time on the phone/computer with the cam guys. I understand that the right cam is absolutely crucial to make everything run correctly.

The compression numbers I am looking for are right around 10's so that should be good. Does the computer even 'see' compression. Hypothetically If I had a stock engine with 10.5:1 compression wouldn't everything be the same except for it being maybe a bit too lean and have more power? My real lack of understanding resides mostly in the computer part of this build. I really don't understand the system in detail.

Apeiron

If there was unusually heavy wear or damage in the cylinder walls that was deeper than .030", you could need it bored out further.

.010" under refers to the crank. To recondition the main and rod journals, the crank is turned .010" undersize and thicker bearings are used. Again it's possible that you might need more than .010" taken off, or your crank could have been turned once already (even from the factory).

If you increased the compression while keeping everything else equal, you wouldn't be lean at all. The engine will still be pulling in the same amount of air and fuel on each stroke, it'll just be squeezing it tighter before lighting it off.

steve102972

iTrader: (1)

Raising your compression and changing your cam is going to raise the volumetric effiency of your engine. Your going to want to change the timing and timing curve, not to mention the fuel map to get the best performance out of your engine.

Avernus

Right I hope it's not already .010 over. That seems like it would be weaker and I don't need a weak crank.. Thats just, weak. have I said weak enough? don't mind me i'll be going there in a week.

..I digress,

Yea i don't know why I wasn't able tin envision that the engine wouldn't run lean. I understand now though. Thanks.

Are you saying that I will need a completely new PROM? The computer doesn't have tolerances for adjusting? Ex. won't the closed loop mode be fine since the computer will change the amount of fuel as directed by the 02 sensor? I can understand the WOT throttle problem though. WOT is a set curve right?

Ah and a btw to ozz, I called Compcams they told me that the Thumper wont work in a TPI engine with out a modified chip but he directed me to a few good cams for me. All of the possibilities are here. What does it mean gears? Like timing gears? Do the gears make a bad noise?

Apeiron

.010" is a hundreth of an inch. The rod journals are 2.10", so you're reducing the size of the journal by less than half a percent. You could even grind the crank down by .030" or more and still have no real effect on strength. These days though, the price of cast cranks is cheap enough that sometimes it's not even worth grinding the crank when it can just be replaced.

The Thumpr line is garbage anyway, it's designed to give a lumpy idle for show cars, not for making power. Anything bigger than the 252 you're probably going to need to machine the heads for, but that's probably also about as big as you could go without chip tuning.

Where are you seeing "gears"?

Avernus

http://www.compperformancegroupstore...y_Code=RLERCAM

This is just an example cam but it's in the "will require" second on the simple page. Another thing I noticed is that all of these say they will not work with stock springs? Is this true? will I need to get a whole new valve-train to support this thing?

Apeiron

Ok, they're saying that that cam needs taller gears than the typical economy 2.73 ratio that a car might have.

Larger lift cams absolutely will not work with stock springs or with stock unmodified heads. Upgrading the valvetrain components is an important part of a cam swap.

Ozz1967

iTrader: (4)

Actually, the August 2008 Edition of Hotrod did a write up using one of the Thumper Cams and they had some really good reviews on it. Of the five they tested it was also the only roller cam. They tested each using both Vortec heads and AFR 195 heads. The specific one in question is the Thumpr 283THR-107.

Apeiron

Sure, and if they'd done a proper fair comparison with a cam designed for performance instead of noise, it would have looked like crap.

Avernus

Why kind of headwork will need to be done? Machining and new parts or just some new parts?

Apeiron

To with with a high lift cam, you need to machine down the valve guide bosses. In stock heads they're too tall, and the valve spring retainer will smack into them when you increase the lift. While you're at it, the valve spring pockets usually need to be enlarged and/or deepend to work with the springs that a larger cam will need as well.

Avernus

Alright guys I'm off for Verrona VA. Hopefully he will have internet, but I would just like to thank everyone for all the help. I'll keep pictures and a journal about the build. So thanks again and wish me luck =)

DIGGLER

iTrader: (1)

if i was building a tpi motor it would have a set of afr 190's and a holley stealthram intake before it went back in the car. (or a similar setup)

stock intake and heads are terrible.

Avernus

HELLO!!! Ok so I finally got some internet so I am able to report now.

The engine is out of the car and is completely apart. I have started to clean everything get it ready for reassembly.

Digger, Thank you for you contribution. An intake would be nice, but consider this; It’s not everyday that one gets to take an engine out of the car with free machine work. Besides that an intake can VERY easily be swapped out with the motor in the car. Then coupled with the fact that the intake is ~2 grand and heads are 1k. Case and point: I will be making far more power/ dollar the way I’m doing it. If you disagree, Think about how much horsepower you gain from an intake vs. Increasing the compression ratio raising displacement and upgrading the cam and Headers. Please don’t take this as an attack it’s just my opinion on the matter.

The news: The bearings all around the block, cam and crank are in FLAWLESS condition. Honestly the first metal surface isn’t even scratched. The Cylinder walls are perfect with no honing necessary. The only problem was the pistons. 3 of them were in this condition.


This struck me as very odd but I guess it doesn’t matter because they will be getting swapped out.

The Question: What is the compression ratio of the stock engine?

The Plan: I am buying the “sealed power fel-pro” engine rebuild kit which has a compression of 9.7:1. We are going to machine the heads/block a little to hopefully achieve >10.0 Comp Ratio.

The pistons are going to be .030 over hyper and the kit comes with all the bearings, rings and gaskets.

The Cam is still undecided, but I’m going to call comp or more likely crane tomorrow and talk with them for a few minutes about the correct cam.

Head work is going to be done. The usual Port and polish and machining for the cam lift will be done. This will help with the new springs that are going to be ordered.

The build finishes off with some Hooker 2055’s and a custom Y pipe back to a cat and cutout. The rest is stock exhaust to keep it quiet for the strict piggys around where I live. Yes, I know it will hinder performance immensely that’s why the cutout is electric and will stay open most of the time.

The opinions/comments/concerns/complaints: I want yours, please and thank you.


The Thanks: Thank you everyone for helping me with this build I really would have been much more nervous about doing all this if it wasn’t for the support from you all.

Pictures can be found HERE. in most likely less than 2 weeks. Sound clips and video's to come.

Apeiron

Stock you had about 9.3:1.

Do you know which pistons are in the Sealed Power kit? Even though they say 9.7:1, rebuilder pistons in those kits almost always have the piston an extra .010" or .015" down the hole so that you can massively deck the block and still have a ton of piston-to-head clearance. You might find you're actually losing compression.

Avernus

Slight change in "the plan" The kit that I found in the summit book isn't online or it's under a diffrent name. here is the kit I ordered

http://store.summitracing.com/partde...0&autoview=sku

I also found my camshaft I think. I understand I need a chip and I'm not going to run it hard till i get one or even then after.

Cam: http://www.compcams.com/Cam_Specs/Ca...?csid=195&sb=2

What do you all think of that? Is it going to sound good? Lobey?
----------
one more thing. can someone direct me to the right springs, and retainers. I'm a dummy at all that. Thanks a million.

five7kid

iTrader: (14)

Use the springs and retainers they recommend on the cam sheet. The second ones are the "better" ones.

Don't forget getting the valve guides cut.

Avernus

Valves are getting sleeved.

I ordered these springs and Retainers

five7kid

iTrader: (14)

Sleeved valves???

Apeiron

I'm assuming that means new valveguides.

Avernus

yes, the guides.

Screamin86

iTrader: (1)

regardless you should need a honing since new pistons and rings are going in. but thats no big deal

Avernus

updates:

To start I machined out the old exhaust valve seat cast in the block and put in hardened valve seats. After that I did some porting on the heads. That was hard work because i was out in the sun and it was HOT. eventually I ported the exhaust and got rid of the lip on the intake valve seat. Don't worry i didn't port the intake too much.
Then The valve guides were drilled out bronze sleeves were put in place.

Tomorrow is going to be Christmas. More updates to come.

The parts will arive tomorrow so the block may be bored out by sundown.

Avernus

Holy crap did i mess up?

The kit I ordered - http://store.summitracing.com/partde...0&autoview=sku

It says ~9.7:1

When i do the calculations I end up with like 10.5-11.2:1

That is VERY bad if I have done the math right.

bore 4.030
Stroke 3.48
CC 64
head gasket: .042
deck: .020

Am i missing something?

Apeiron

You're probably not allowing for the distance of the piston face down the hole. That kit will probably have the typical "rebuilder" pistons that are an extra .010" down-hole, on top of the nominal stock .015".

Avernus

OK so the pistons say +5. does that mean that They increace the size of the cmbustion chamber or decrease? I assume it means i'd have ~69Cc heads. Which would put the CR at ~9.6:1

Apeiron

That means that the valve reliefs add 5ccs to the combustion chamber volume.

Avernus

Well, Good news! After a little persuation from the battery charger the car started right up and runs strong. I feel like the cam should sound a little lobey-er but, I'm still very happy with my results. If you have any idea's please chime in. I havn't mashed it yet and probably wont until I get another 50 miles on it. I'm thinking of getting it dyno-ed for kicks. I'm in the middle of trying to upload a video of the car but, it's taking forever so i'm going to just post back when it's done.

Anyway. Thanks for all the help from everyone! This build really couldn't have gone any smoother. I hope you all like the outcome as much as me.

till later
-Av

Avernus

Video

Screamin86

iTrader: (1)

sweet glad ya got it done. if only i could get my car back on the road now lol