SBORule

The perfect 350 to start with is Diesel, preferably the D block version not the DX block because the D block has .842" lifter bores and that saves money not having to bush the lifter bores down from .921" like you do in the DX block, unless you want to use stock type Hyd Roller lifters, not the best but doable.

If you stroke the crank to 3.5" inches by offset grinding the rod journals on the crank down to the small journal SBC 2.00" size and buy 6.00" long SBC Rods instead of 6.200", you can pick up a set of CP pistons that are made for an Oldsmobile with the right valve reliefs and Compression height for use with a 3.5" stroke crank and 6" inch rods, unlike the SBC pistons that have 23 degree valve reliefs instead of the 8 degree valve reliefs an Oldsmobile uses. Not that their won't be enough valve to piston clearance if a SBC is used and lift is less than .560" the CP pistons would set you back a few hundred more bucks. Stock stroke crank, cut rod journals down .025" for a 2.100" large journal SBC rod. The width you widden the crank journals depends on what kind of clearances you are going to run, if you are going to run loose clearances, then you wouldn't want to widden the rod journals as much if you are going with say .025 to .027" clearances as opposed to .030-.035" clearances. Side clearances are set to allow/restrict oil flow through the bearings, depending on desired rod bearing clearances you plan to run and thus, how much to widden the rod journals on the crank.

If you really want to know what to do and what to have your machinist do, you should contact Bill Travoto at BTR via email at bill@btrperformance.com or call him at 585-303-7560 or go to his website at http://www.btrperformance.com and or http://www.highperformanceolds.com

He has everything you need in stock.

He also has a 10 part video series on YouTube that anyone building an Oldsmobile engine should watch, just go to YouTube and type in BTR S71 Turbo and that should get you in the neighborhood.

captjim

I am confused by this post. While the lifter issue is easier, almost every expert prefers the DX block. IIRC, there are issues with the main bolts on the D block.

Which CP pistons are you referring to on the stroker? Custom? Also, most shops will cut reliefs for a hundred bucks, just get flat tops and cut reliefs or dish as required.

SBORule

Some early, first run D Blocks had main bolt issues, just need to drill and tap those threads a little deeper, no big deal.

The CP pistons are available from BTR off the shelf and are in stock for a SBO with a 3.5" stroke crank for use with SBC 6.00" rods.

Well, I guess you could get these pistons, rods, rings etc. from other places if you want to gamble and roll the dice.

captjim

I have never seen those listed anywhere. So a bore of 4.125" and a p/h (if I did the math correctly, it is late) of around 1.580. How much are they and what are the specs? Does he also do the carnk and offer the whole "kit". I actually looked into that but decided I could not make the numbers work.

cutlassefi

O.K for the record SBORules post is a little confusing.
The D block takes a 3.00" main/425 or similar crank so you're not going to be able to cut it down anywhere near the SBC rod journal size with a 3.5" stroke.
Secondly Olds engines are not 'interference" engines, you can use a 23 degree Chevy piston with no issues, unless maybe you've got .650 lift on a tight lobe sep.

And for the last time don't widen the rod journal anymore than you have to, cut the rods instead, it'll reduce some of the offset.

SBORule, please don't post your "how to hot rod/stroke a SBO", I don't have enough time to edit it.

71boosted-good luck in your build. Let me know if I can help in any way.

olds 307 and 403

Jim, Summit carries those pistons. They also make 350 pistons in a 4.065" bore with stock olds rods and stroke, then a hone is all that is needed. I just wish all the avialable, quality pistons weren't flat top. I know most performance builds want that compression, tough to keep under mid 9's.

71boosted

I'll take the crank and the rods in and have them machine them enough to be acceptable. Order in pistons to get me in the 9.5:1 ratio, maybe more and run water/meth

captjim

Learn something new everyday, here is the link to the strokers,
http://www.summitracing.com/parts/cn...ake/oldsmobile

This is a perfect application for the #8 head. Flat tops and the #8 head put Cr in the low 9.xx range. Or, use the Pro Comps.

olds 307 and 403

That what I was thinking for the 4x4 350 build, mildly done #8's would yield perfect compression for the TBI fuel injection. The 5A 307 heads on there now, would yield 10+ to 1.

71boosted

I run 7 heads, but I can get forged pistons and rods for less than those pistons.

71boosted

Cutlassefi, with the hbeam rods I don't think I can really shave the rods down

captjim

Not sure how. Speed Pros are $400+ and you can't get Olds rods for $200. Also, I am going to take an educated guess and assume the CP pistons are quite superior to the Speed Pros. And as 307/403 stated, with 68-72 350 heads cr is too high, though it is a simple matter to cut a dish into them.

71boosted

Not running olds rods and can purchase the correct dish to get the desires CR I'm after

captjim

That really isn't an answer. Which pistons and rods? Part numbers, links.

71boosted

I'm doing the Chevy internal stroker route. Std 400 pistons used with the 5.7" rods, 6.200" hbeam rods and the 330 crank machined to the 2.100" journals

SBORule

You could use the stock crank that came in the diesel block and have the rod journals turned down to 2.100" no problem, even 2.000" is more than likely safe. You wouldn't need main spacers in the block and gas block caps like you would if you wanted to use a 330 crank. The stock Diesel cranks can handle 600HP like the 350 N cranks can. 330 cranks are good for up to 800HP.

Believe me, you go more than .580" and the valves will be kissing the pistons.

I'll agree you shouldn't widen the rod journal anymore than needed to achive proper side clearances on the SBC rods based on rod bearing clearances that will be engineered into the crank.

You do seem to enjoy giving bad advice.

In other words, let him know if he can sell you something.

SBORule

I don't know who's SBC 400 piston for a 5.7" rod you plan to use, someone mentioned Speed-Pro but Probe makes a good forged piston as does Pro-Tru which are far better than Speed-Pro's and they don't weigh as much.

Who's 6.200" SBC rod are you going to use ? A good set of I-Beam rods are good in engines in the 500 to 600HP range and weigh less than H-beam rods.

captjim

Again, what part numbers are you using that you can get forged pistons and H beam rods for $625??

cutlassefi

Well, let's give the facts, and I don't need to shout.
If you're only going to 4.125 bore or so with a 3.5" stroke, why do you need to use a diesel block? Your hp is limited by the stock cast crank iron diesel crank anyway. Didn't think of that did you. And at that rpm/hp level why would you want to use a crank with a 3.00" main vs one with a 2.50? You can easily use the gas block for that hp level. That doesnt make sense to me.

Seeing as how all Olds share the same style heads, explain this to us.
I did an iron headed 455 with .584/.592 lift hyd roller, why did the valve not hit the pistons? I had over .150 valve to piston clearence, at overlap. Got any answers for that? Give an example of a build you've done that had over .580 lift where the pistons threatened the valves. I'm all ears.
The simple truth is you're wrong. Olds valve angle doesn't pose a problem unless you're using much larger valve and/or lift in the range I mentioned along with a tight lobe sep.
Ask yourself this, even stock Chevys, Fords, Pontiacs have valve reliefs in the pistons, why are there not any in any Olds, ever?

And as mentioned, take the extra off the rods not the rod journals. That helps minimize the offset. You basically said nothing there.

Please show me where I've given bad advice, please. I'll correct it. I've already shown where you did that, will you do the same? You haven't yet.

Have I charged anybody for any advice, ever? Please speak up if I have.

Bruce, imo you wiffed, again.

VORTECPRO

Cutlassefi, you didnt charge me. Hows the dyno test of the 850 carbed 455 coming?

cutlassefi

Thank you, should be next week. My dyno guy was tied up doing a week long test for Mopar Muscle magazine. That put him behind a little.

71boosted

Weren't those pistons advertising for $685? I'll post the exact ones

71boosted

I didn't mention a damn thing for what I was using. I simply stated that I can find pistons and rods for less than 685 that just those pistons cost! I never said speed pro never said anything for what I was using.

How about we stop using my post as a battle ground for who is and isn't in the right. I got the info I needed with what internals to use that will make a nice block and I appreciate the help.

captjim

Hey, I am not using it for any battle ground. YOU posted that you could get forged pistons AND H beam rods for $640, the cost of the CP pistons. I simply asked you where. Since you made 3 posts with no real data refusing to answer, I assume it is not true.

captjim

Nope, $638

olds 307 and 403

BTR Performance offers those pistons, pins AND rings for $640. I have never heard anything negative about Bill as a business man. I have seen one of his motors run low 6's in the 1/8th at our local track. Good to have piston options, especially high quality ones.

71boosted

I'll post the set I'm talking about. Don't UBS to bring hate towards me I'm just saying that for my route that's insane to spend just that on pistons when I could get both for the same. And I apologize I thought it said 683. So I may have lied. I can get rods and pistons for a bit more than the 638 lol

SBORule

Geeeze you again?

Because it's stronger than a gas block.

Do you know how much abuse a stock Diesel crank can take?

Do you know the horsepower limitations of a stock Diesel crank ??

Maybe you should talk with some Super/Stock Olds racers, that have set world ET & MPH records with a stock Diesel crank in a Diesel block.

Again, you should talk with some people who are running a stock diesel crank.

Yes you could use a gas block 350 in the 400-500HP range, that's true, you could use a diesel block with a stock Diesel crank too.

71boosted

Pistons are a KB753-STD

Rods are a PC41215

450.00+220.00=670.00

No BS just stating I could when I thought price was $683

SBORule

I don't know where to start, you are all over the place, what does building a 455 have to do with using SBC 400 pistons for a 5.7" rod on SBC 6.200" rod? The valve reliefs in a SBC 400 piston with valve reliefs are cut at 23 degree angle and usually for valves in the 2.05" & 1.625" so lets say his heads have 2.072" & 1.710" can you see why they would have Piston to valve clearance issues? There are plenty of Olds pistons that come with valve reliefs, are you kidding?

SBORule

Spend a few more bucks and get some Pro-Tru or Probe.

Who makes the rod ? I take from the price they are I-beam.

captjim

found this, $220 for the set, good price,
http://www.ebay.com/itm/SMALL-BLOCK-...-/170881189930

pistons I could not find for less than $500, but that does not mean they aren't out there.

71boosted

Both available on eBay, and those were hbeam. Maybe not for the racer but def works for my needs

cutlassefi

If you keep the stock stroke, grind the crank to fit those rods and use the piston listed, the KB IC753, then with a 65cc combustion chamber you'll have about 8.4:1 compression. Is that what you want?
If not then I'd use the IC754 instead. That'll give you about 9.25:1 with the rest of the combo being the same as listed above.
And yes you can grind the side of those H-beams the same way you would anything else. Have both ends checked as well, they'll probably need to be opened up on the pin end.

SBORule

What would we do without ChinaBay?

Make sure you are getting the right pistons for the desired compression ratio and make sure they have floating wrist pins and not press in wrist pins because those H-Beam rods listed above look to be bushed on the small end.

There isn't any mention of + or minus balance on those rods, hope you have them checked and balanced on both ends.

Hope you are having this assembly balanced by a reputable machine shop that has a reputation on machining engines for racing.

You still going to need a 330/400/425 flexplate and a new dampner would be a good move since it has to be balanced with the crank and flexplate.

cutlassefi

[QUOTE=SBORule;472796]

Hope you are having this assembly balanced by a reputable machine shop that has a reputation on machining engines for racing. Why do they have to be race shop? Suppose they only do Chevy Race engines. Explain please.

QUOTE]

Just curious why that has to be.

380 Racer

[QUOTE=cutlassefi;472797]X2

71boosted

I have a couple reputable shops I will price out. I'll have those rods checked if I use them, with the correct piston to get the desired CR. Alongside the crank, flexplate and dampner.

Thanks for pointing out. I have the basics down tho for what to make sure of being checked.

SBORule

[QUOTE=cutlassefi;472797]Lets see, hmmmmmmmm

Pretty much, that's why.

cutlassefi

[QUOTE=SBORule;473173]Huh? Any good shop should be able to do those things. You don't need a "race" shop.