SHP block - 1pc vs 2pc RMS
 

I am trying to decide which block is better for me.

I am currently building a 400sbc (330817) 2bolt engine right now. I need this to run for one more year and then upgrade to a SHP block for next season.

I am trying to potentially use some of the same parts to carry over to the SHP block.(valve train)

Some of the benefits of the 1 pc rms is that I can use an OE roller cam and lifters. And potentially better sealing of the rear main.
http://www.summitracing.com/int/part...211l/overview/
A roller cam set up is about $500

Some benefits of the 2pc RMS is slightly cheaper.
http://www.summitracing.com/int/part...1211/overview/
A retro roller cam set up is about $825 for cam and lifters

Any more insight that I am missing?

Re: SHP block - 1pc vs 2pc RMS
 

A certain amount can be found here:

http://www.dartheads.com/products/sh...all-block.html

Including "Provisions for OE stock roller lifters and cams", applicable to the whole product line.

Re: SHP block - 1pc vs 2pc RMS
 

If you plan to re-use the crankshaft that will dictate if a 2 or 1 pc rear main is needed on the future SHP block

It will also determine the journal size of the future block as well.

SO if you plan to re-use the 400 crank from your current 400 build the future SHP block can only be 2 pc rear main with 400 main journals.

WTH are you going to race now? it's almost December next season starts in 5 months ! or do you mean 2017?

Re: SHP block - 1pc vs 2pc RMS
 

Shp has roller cam provisions already. Dont matter what rear main.

If you buy new crank then just get 2 pc, more options available that way.

Re: SHP block - 1pc vs 2pc RMS
 

Right now I am rebuilding a stock 400sbc.(cast dish pistons, stock 5.565 rods and 3.75 stock crank) 9.2-1 compression, afr195, LT1 intake, 1 7/8 LT with hopefully a 150hp shot of nitrous.
I am going to run this engine for the 2015 season.

Then start assembling the SHP 400 block a year from now. Still deciding on a 406/414/421 cubes. Fully forged rotating assembly
AFR 195 for now, then for 2017 go with AFR227.
By that time I'll run a carb and different nitrous set-up, and hopefully roller cam of somesort(solid or hyd)

I will not use any of the stock rotating assembly(just possibly the valvetrain if it transfers over)

Re: SHP block - 1pc vs 2pc RMS
 

So you can get a 2 piece RMS with the ability to run OE roller cam?
So you would have to use the "spider" , or can that handle big HP?

I'm trying to get away from using the retro roller lifter, lots more $

Re: SHP block - 1pc vs 2pc RMS
 

Thats what i have now. 2 pc block and oem roller stuff. Well i had spider but recently went link bar lifters but still use 87-99 style step nose cam, same timing chain and cover, same retaining plate for cam.

I am one of the highest hp numbers that i know of running thru the shp block...its a very stout piece

Hopefully carl sees this thread from cnc blocks northeast

Re: SHP block - 1pc vs 2pc RMS
 

At which point did you switch to the link bars?

Also, what is the part number of the OE roller lifter that you used?
Solid or hyd?

Re: SHP block - 1pc vs 2pc RMS
 

Stock dog bone lifters with a .700 wheel are not as dependable as a tie bar lifter with a .750 wheel.

Re: SHP block - 1pc vs 2pc RMS
 

So at what point should a person switch to the link bar set up?

When using big lift cam?
Higher rpm?
Better geometry?

What about the PRO shp block? with the BBC lifter bore. Why is that set up better?

Re: SHP block - 1pc vs 2pc RMS
 

With cams over 230 degrees duration go to a better lifter one made out of better material and a bigger wheel.

BBC's lifters are only a .843 lifter bore same as the SBC,

The Dart SHP Pro block has .904 lifter bores and uses a BBC cam tunnel.

Anytime you can go to a bigger base circle cam = smoother valve action better profile, I machine a lot of blocks for 55MM cam cores which seems pretty popular now a days SBC, BBC and SBF.

.904 lifters, Bigger lifter and just about all .904 lifters are pressure fed, Bigger wheel = less revolutions around the lobe. Bigger body = stronger lifter. Bigger wheel = less pressure angle.

Going to a .904 lifter is very common now.

Re: SHP block - 1pc vs 2pc RMS
 

When i ran stock lifters, they were stock gm ls7 lifters. I ran them just fine in 230 deg cams at .600" lift but really it comes down to spring pressures.
I switched to morel link bars when i went 246 deg .640" hyd roller that required 180- ish lbs seat pressure and 450 lbs open. Thats getting to be high for a gm lifter. Gm ls7 lifters are better than pre 97 lifters. They have better valving internally and are good for most applications.

Re: SHP block - 1pc vs 2pc RMS
 

Check with Chris Straub http://www.straubtechnologies.com/ he knows the stats on those OEM lifters and what they are good for.

Basing all our info on just one engine is not as good as a shop that has seen what happens when you exceed the limits of OEM lifters. I wish I kept track of all the calls and emails about OEM lifter failures. Chris will confirm what I am saying.

Re: SHP block - 1pc vs 2pc RMS
 

Orr, do you have a PRO block, or just SHP?

Re: SHP block - 1pc vs 2pc RMS
 

That is correct but i was told from chris straub that pressure and rpm start to become a concern on oem lifters. Key word is exceed limits as you stated. He convinced me to go morel and my cam guy also suggested that they would be a good idea. My build was on the edge of comfort zone.

That being said i am not basing this on just one engine lol i am deeply rooted in the car scene in my town and know all the shops. havent seen one lifter failure with the new ls lifters used. There are dozens and dozens of cammed cars around here with no issue. Cams arent crazy and spring pressures arent super high so they do live well. IF you dont push the limits.

Re: SHP block - 1pc vs 2pc RMS
 

Shp base block machined by Hinkson Auto above. Beat on for years, torn down to inspect and it was all fine. I didnt need to refreshen but wanted to openup ring gap more for the high boost i now run.
I highly recommend a block from Carl

Re: SHP block - 1pc vs 2pc RMS
 

Thanks

Justin you have been on the edge for a long time and I love it!!!!

Re: SHP block - 1pc vs 2pc RMS
 

Any one building a 3.750 stroke or smaller I would recommend the Pro Block with a stroker rod like a Callies, Crower, Scat, Oliver ETC there is plenty of cam to rid clearance.

Re: SHP block - 1pc vs 2pc RMS
 

So for a 4.155 bore x 3.875 stroke you would recommend a pro block?

Re: SHP block - 1pc vs 2pc RMS
 

If you were going to use a Honda journal rods or the Callies Ultra HD 2.100 rods you can use the 2.100 Callies Compstar rods but will have to use a reduced base circle cam.

Here is a build I did last year.

http://www.chevelles.com/forums/showthread.php?t=481081

Re: SHP block - 1pc vs 2pc RMS
 

Those hd rods are nice but to expensive for na street builds imo. Either block would be nice, just depends how crazy you get with your build

Re: SHP block - 1pc vs 2pc RMS
 

I have some of them running street and strip no problems, Some guys don't like running small base circle cams.