Gm crate engine

[MikeB]

Originally Posted by Steeveedee

I'd have to say, I'm curious what is so special about a .040 over 350, as opposed to a stock bore?

Cylinder wall thickness, especially on blocks that have core shift.

https://mooregoodink.com/what-is-cor...t-detrimental/

[garyd1961]

The GM L31 or L31-R is a good choice. With a good carb and exhaust you will have around 300 hp and close to 400 ftlbs of torque. That's with the factory cam which I run and it idles really smooth with decent gas mileage. With a simple cam and valve spring swap you can get 400 hp. The vortec heads and roller cam makes a good motor for the money that can be upgraded easily if you want to.

[72SB]

A larger bore, .030-.040-.060 will yield more power. Casting a block with a larger bore, or machining a 350 CI block out .040, will allow more HP/TQ due to a larger piston. Combined with the heads BPE uses and cam selection they can get 400+ HP/TQ out of an otherwise mild SBC using a 220/224 cam on a 113 LSA

A .030 over bore along with a stroker crank will = 383 CI, .040 over a 396 CI which will make more HP and TQ than a 350, 355 (.030) or a 357 (.040)

They have done their homework and are able to offer 50k mi warranty.

My BPE is a 4 bolt main, 1 piece RMS, full roller cam motor. I replaced my 327 baby head 2 brl motor with it in my 67 Camaro. Plug & play. You just need to get a different flexplate for a rear external balanced 1-piece RMS motor but otherwise just transfer over your accessories

[May70]

So ill tell you my swap story:

Lowest entry ls GM performance had a year ago was the LS3. GM quote for the turn key package was $15,465+ shipping.

If I wanted a modern manual (tremec 6 spd TUET16885) it would have been cost of the engine ($7848) plus $7797 for the transmission, trans control pc/harness, hydraulic pedal conversion parts, crossmember PLUS engine pc, mounts etc etc etc.

It was a solid $20k plus to do that aka - out of their minds.

I pulled an 03/04 LQ4 / 4l80 / 14 bolt for a couple hundred bucks. Paid a lot of money to have them all rebuilt but Ill be in it about half (with expensive stuff I didnt have to buy like a fancy accessory drive).

[Steeveedee]

Originally Posted by MikeB

Cylinder wall thickness, especially on blocks that have core shift.

https://mooregoodink.com/what-is-cor...t-detrimental/

I understand doing that for a rebuild, but they're doing it on brand new blocks of their own manufacture.

[72SB]

BPE advertises my motor as a 355 which is a .030 over 350 block. The specs however note .040 bore so that makes it a 357. IDK if they bore the blocks they get or they are cast in that size and just machined/honed like any 350 block would be during manufacture to be native .040 larger cyl than a 350 block.

In the shop tour video they note the new castings are received and they deck them and finish the front and back of the block. Not sure what they do, if anything, to the cyl holes themselves. They have been using a foundry in Ohio but my understandings now is they are building their own as an expansion of their engine plant in Nebraska. Many of the machines they use in building the motors they designed and made themselves. That machine that puts the rings on pistons is pretty cool. Several of the assembly steps are robotic and unlike the major auto engine plants, they dyno every motor which to me adds a layer of comfort knowing the motor ran, made X power and if any sign of a problem would show during that process

Having purchased a few SBC & SBF over the years from various rebuild shops, the BPE has had zero issues for me vs "something" from the others

[MikeB]

Originally Posted by Steeveedee

I understand doing that for a rebuild, but they're doing it on brand new blocks of their own manufacture.

OK, I see what you mean. Nothing special about .040" over. Usually that means the bores wouldn't clean up at .020" or .030". But maybe their blocks are cast that way with thicker cylinder walls, and advertising a 357 separates them from other builders.

That said, Blueprint sounds like a good company.

[Steeveedee]

I was impressed with the video, and was heartened to see that one doesn't have to be ASE certified to get the warranty. I "gave up" my certs, if you will, when I graduated uni and went to work as an engineer. I never stopped working on my vehicles, though. I haven't done an engine swap in about 8 years, but it's just like falling off a bicycle, really.

[slikside]

Subscribed. Lotsa good info here. Someday...

[6T7 C10]

When I was building my 67 I was able to buy a new never used L31 350 SBC. Been happy with my set but a 383ci would be a dream and really fit the purpose you described. Good luck and post your progress.

[SCOTI]

Originally Posted by MikeB

Wow, I had no idea. Is it a one-piece main seal block and drilled for OE-type roller cam and lifters?

I'm still curious why the bore would be +.040". I know some engine suppliers go out to +.060", but that's out of necessity and not a generally a good idea. At the shop I worked for, we would not go any more than +.030". Maybe the Blueprint blocks have thicker cylinder walls than GM blocks.???

x2. Doesn't make sense to bore out a 'new' cylinder/block just to target a cubic inch dimension(??). More CI from a stroker crank set-up? Sure; but not boring cylinders just for a 'C.I. number' increase. I could understand if it was done on blocks that had poor bore specs that a hone could not correct but that seems suspect.

[72SB]

these are the specs for the 355 (really 357) BPE I got. .040 bore. It notes "seasoned block" which is what normally a "crate" motor is that was "rebuilt". In my case my BPE has a "new" 350 block either cast or machined (bored) .040 over. It has "Blueprint" cast right on to block so it is a "new" block and when I asked BPE about why they say "seasoned" block in their description they said originally, they did get old blocks to rebuild but in the last few years they use new blocks cast in Ohio and just have not updated their web 411 to say so. Their shop video in the beginning describes what their SBC blocks are (gen 2 SBC)

https://blueprintengines.com/product...ads-roller-cam

[SCOTI]

Originally Posted by 72SB

these are the specs for the 355 (really 357) BPE I got. .040 bore. It notes "seasoned block" which is what normally a "crate" motor is that was "rebuilt". In my case my BPE has a "new" 350 block either cast or machined (bored) .040 over. It has "Blueprint" cast right on to block so it is a "new" block and when I asked BPE about why they say "seasoned" block in their description they said originally, they did get old blocks to rebuild but in the last few years they use new blocks cast in Ohio and just have not updated their web 411 to say so. Their shop video in the beginning describes what their SBC blocks are (gen 2 SBC)

https://blueprintengines.com/product...ads-roller-cam

I'm 100% aware they're casting their own blocks (& doing similar for their heads). I'm not sure how well that will play out so time will tell.

That being said.... If it's indeed a 'new' casting & their website hasn't been updated, what are you actually getting? What is their actual 'as-cast' bore size standard for the SBC?

[Steeveedee]

Originally Posted by 72SB

these are the specs for the 355 (really 357) BPE I got. .040 bore. It notes "seasoned block" which is what normally a "crate" motor is that was "rebuilt". In my case my BPE has a "new" 350 block either cast or machined (bored) .040 over. It has "Blueprint" cast right on to block so it is a "new" block and when I asked BPE about why they say "seasoned" block in their description they said originally, they did get old blocks to rebuild but in the last few years they use new blocks cast in Ohio and just have not updated their web 411 to say so. Their shop video in the beginning describes what their SBC blocks are (gen 2 SBC)

https://blueprintengines.com/product...ads-roller-cam

I can understand punching .040 over on a seasoned block. Maybe they're just trying to make numbers that don't match "common" production displacements, so they stand alone?

[72SB]

Steve, more CI= more HP. Making a new block .040 over is just mirroring what they did on a rebuild combo for piston size, head/cam combo when they would take a used 350 ci block and machine it out to either .030 or .040 only in the case now they just use new cast blocks .040 over. IDK if they are cast as that size (357)_ or they actually bore a new 350 block .040 over to get the 357

starting with the original SBC, Gm 265 made x HP, 283 more, 327,350, 396, 427 were respectively more HP as standard builds

BPE "advertised" HP/TQ ratings are always lower than "actuals" which are documented with a dyno sheet for every motor they make. IMHO they build a very good and reliable engine which comes with a 3yr/50k mi warranty even including cost of labor (fixed rate) to R&R a warranty claims vs just "defective parts" if a shop installed the motor

I had my motor direct shipped to Rory's place, Fontana Motorsports, in Simi Valley. He installed it in my Camaro. 1st time I have ever had anyone other than me put in a motor but at the time my hands were not cooperating, so I begrudgingly had him do it. Rory is a solid guy and does good work

[Steeveedee]

I'm pretty clear on the relationship between cubic inches and horsepower.

[SCOTI]

Doesn't make sense to overbore it from the start if it's spec'd like GM's block (4.00x3.48) as cast. That eliminates longevity on an expensive core part.

[72SB]

Originally Posted by SCOTI

Doesn't make sense to overbore it from the start if it's spec'd like GM's block (4.00x3.48) as cast. That eliminates longevity on an expensive core part.

yes it leaves less room for a rebuild with .060 being as far as one would want to go. IMHO most, including me, who buy performance motor be it rebuilt or like BPE larger than 350 bore on a SBC will never see the milage (100K+) on these motors

If it is just a stock replacement motor one wants than just buy a new 350 from GMPP. small iron head valve, 350 ci, around 2xxhp vortec head motor. Some do and sell off the heads and stab a cam and put aluminum heads on those motors to get what is considered minimum HP for a fun streetcar now being 400 ish HP

2 of my hobby cars have either a 383 or 357 and at most see 3-5k mi a year so for me I will never see 100k mi on those motors...although I do have 45+k mi on my 383 but it took 17 years to put that much on it. Both run great, no leaks and no oil use. YMMV

[MikeB]

I suspect the TQ and HP differences between 350 and 357 are negligible. I seriously doubt they did it for power reasons. Maybe they simply had an overstock of 4.040" pistons. Don't laugh. It was not uncommon for auto manufacturers to use "leftover" parts whenever they could on next-year model production vehicles.

We're not saying you got a bad engine, only that it's unusual.

[dagnabbitt]

Based upon their own data the 355 (yes, 357) is significantly more powerful than the 350: about 10% more.

I'm inclined to believe them. It appears that they underreport the hp and torque, which is what a good company would do. I was told I was getting a 355 with about 390/410 and I got one with 414/440.

I'm buying another one if the Canadian dollar is ever worth anything again. I don't go the the track, and this kind of power is more than I can reasonably be trusted with on the street.

[72SB]

Mike

I don't know the reason why .040 pistons were what was shown in "specifications" of the particular crate motor I bought which is why "I" describe it as a 357. . It is advertised as a 355 which is a 350 ci with a .030 overbore.

Blueprint builds several hundred SBC at a time and their offerings are either 355, 383 or 396. A 396 uses a .040 piston with a stroker crank.

BPE sent me an email, on request, of specific parts used in the part # (engine) I ordered. "GM 4 bolt main, 1 piece RMS, bored 4.040
GM cast crank 3.48 stroke"

with a relatively small cam, 220/224 on a 110 LSA and their 64cc chamber, 195cc intake/75cc runners 2:02/1:60 valve heads with 10"1 compression this motor dyno at 413 hp/411tq. All with a 30 month/50k mi warranty

[ghackett1]

Originally Posted by 72SB

Another vote for Blueprint Engines. They are new motors, not rebuilds. Blocks are cast in Ohio. They dyno every motor and back it with a very good warranty. You can buy direct or from places like Summit. Free shipping. I bought direct, motor was here in 4 days. 357 making 411 HP 413 TQ using a 600 cfm carb. Have a Hughes 2k standard size stall. Runs and drives perfect and has a nice cam idle but nothing stupid choppy

I also had a S&J 302 for my 70 Torino....had to send it back for replacement. YMMV

This thread is from last year but I want to clear something up, I purchased a Blueprint crate engine 355/390HP in June of last year and it was a GM block dated K/21/9 (1989) and the gm block casting number is 14093638..
Motor runs great but the block is not new.

[dagnabbitt]

Yeah, the 355s were not new: they were "seasoned" blocks. They do cast their own new 350s, now, though.

https://blueprintengines.com/product...or-bp35513ctc1