Need Help on engine build

[skipjobe]

I am building a 350 LT1. I bought a balanced forged rotating assemble with a 383 crank h-beam rods with standard bore pistons netting 377. I have found that the 2 bolt mains are good to about 500 hp. I am trying to get my 3400# Camaro into the 10's which will take about a 200 shot about 700hp.
I decided after some research that splayed caps would be the solution, I called a couple machine shops referred on this page and the second machinist said you can not use standard size pistons after splayed caps are installed because the cylinder needs to be bored with a torque plate installed. So my problem is that like most is a limited budget the pistons are already balanced and I don't know if I can swap them. I know many of you have been in similar situations, This is my first engine build and I am already a $1000 over budget whats new? let me know what is the least expensive route at this point. PS. The roll cage is leaning on the wall along with the drive shaft loop the trans is in the shop getting beefed up.

[bjuice]

the cheapest most beefy thing you can do other then the obvious you mentoined above is to:

Stud the bottom end and have you some main cap Girdles machined..basically all the girdle is a 1 inch thick tool steel metal that is machined where it lies flush against your main caps..

the studs you will use will have to be the longer ones to go thru the main caps and the homemade girdle...this will strengthen your mains for an easy 700hp..

now keep in mind that when you stud a bottom end you will need a minimum of a line hone if not a line bore..depending on how distorted your mains are.....the studs have that much tensil strength over regualr bolts..

this is still much cheaper then going the other route...

also i have ran these type girdles on my last 3 small blocks..one made over 1,000 hp (blown)..

hope this helps..maybe someone else will have an idea for you also.

Brian

[skipjobe]

Thanks Brian I will suggest that solution to the machinest and perhaps I can use the splayed caps I have as the new caps with studs.

[cepx111]

Brian, I put studs and a main guirdle on my bbc, that I purchased on ebay. I mention this to the machine shop when I had my block decked and bored but they made no mention of me needing to line hone it? what's the reasoning behind it? I installed the crank and torqued the mains and everything is smooth> I just want to be on the safe side so hook me up. Thx charles

[billhendren]

You would do yourself a favor by taking it apart and align honing it.studs with there fine threads have a higher clamp load against the cap and distort it more as compared to a bolt.I have never seen a block that had studs installed where the mains remained round without an align hone.Bill

[bjuice]

what Bill said exactley.. 8)

Thanks Brian

[cepx111]

Thx guys I'll do that.

[bjuice]

the thing is ..you may get the bearing's and crank to bolt up and even seem like its spinning freely..but whats gonna happen is excessive bearing wear ..and a good chance that heat spots could form on a certain spot on the bearing that is wearing faster and could cause a bearing to spin,,messing up much stuff....

the studs pull the mains down so tight..the mains go from being ROUND to OVAL shape..sometime hard to see by the human eye, but sometime you can see it if you know what your looking for.....but you put a MIC on i and you can see the distortion no problem....the align hone process is fairly simple..some can do it at home with right tools...but if you have to get it done i would say $80 to $150 (high end) would get the job done for you..(standard shop labor)
the biggest thing is getting your motor tore down to that point..if your there already then great...less hassle.
glad we could help.

Brian

[cepx111]

I'm just starting the assembly process, I haven't even installed the pistons yet. I torqued the crank down and plastigauged the bearings and everything was on target but this was done w/ factory bolts, I've since bought studs and a guirdle. I've got allot of money tied up in this engine so I'm gonna get it checked and make sure its right.
Thx again for the help, Charles

[edvancedengines]

the second machinist said you can not use standard size pistons after splayed caps are installed because the cylinder needs to be bored with a torque plate installed.

I question this.

I feel that either you mis-understood him or he is wrong. He is corrent in that if you do the splayed caps and torque them down the block will see a different form of stress than it did previously and can distort the cylinders. I can agree with that.

I can agree that it should be then re-honed with caps torqued after finishing and torque plate honed. I can not agree that it should need to be re-bored and re-honed to a different size though. Just re-honing it, should not require new or different sized pistons.

All advice in this thread is good advice in my opinion.

I suggest to keep your 2 bolt caps and to buy and use a main cap girdle on them but to get the align hone checked and re-honed if necessary. You could also just get the 3 center caps repalced to a 4 bolt cap, but I think at the stage you are at the girdle is best bet.

I do not know who has the main cap girdles for the sb chevy now, but I am also getting ready to look for some for one of my similar projects I am on. I heard that Cat is making them, but have not checked yet. Years ago Milidon made them. I know Probe has them for Fords now.

This similar project I am on, has all machine work completed with two bolt caps, and now has a new owner that wants more power from it. lol. I am also looking strongly at figuring something to do with the rear main cap. To me it does not look real strong. I am not sure if anyone is making a billet cap for the rear of these things or not.

:) Lol :). I just answered my own ignorance by going out in the shop and looking. The GM Bow Tie Rear Main Cap is much more beefy.

Ed

[performanceengin]

PRO GRAM ENGINEERING HAS THE CAPS.

[skipjobe]

Hey thanks, I will copy this thread and take it to my machinist, When I talked to him earlier this week he suggested that clearancing may be a problem on a one piece crank seal motor as the material is thin and may cut into the water jackets. On top of that the H Beam Rods make it worse.
If that occurs is the block junk or is there a repair for it? I was only able to find SBC Girdles on Ebay and it is a Cat. Ford girdles are available at most of the suppliers.

[cepx111]

Heres a link to cat power engine products. They make the bbc main stud guirdle I was refering to in a earlier post if anybodies interested.


http://www.catpep.com/default1.htm

[edvancedengines]

Clearancing the block should not be a major isse but it will be some work to do by hand. Those blocks have been clearanced for a larger stroker so if he is careful and cuts in the right places and does not cut/grind more than needed for clearances it all should be fine.

Instead of water jackets he might want to be concerned about getting into the oil galleries that run at the bottom of the block from front to rear in that block.

All it takes is to be careful and measure and check it and keep checking it a little at a time.

I have done several 396 cu in using the LT-1 Blocks. I have no idea what he means about the one piece seal making the block thinner. Also you can easily make it a block with a two piece seal with an aluminum adapter.

Ed

[skipjobe]

Thanks Ed, That is a relief, do the H-Beam rods require more clearancing than I-Beams.

[edvancedengines]

Thanks Ed, That is a relief, do the H-Beam rods require more clearancing than I-Beams

Yes and no.
I don't think anything requires as much block clearancing as the GM Powdered Metal Rods, but the H-Beams do have the bolt heads hanging down further and will need more than a regular I-Beam Rod will. The Eagle H-Beam uses a short head stroker bolt which does make it easier. The Cat and Scat and I guess the rest use a longer bolt head. This was true lasty year. This year I have no clue.

Ed

[skipjobe]

Actually I am planning on clearancing the engine myself, I saw one article that showed the edge of rod next to the rod bolt machined og ground off. I
also read that there needs to .050 clearance from rotating assemble from block.
I got the main hoop and two of the supports in this weekend steady but slow.

[edvancedengines]

With steel rods .040 to block is fine. With aluminum rods .060 to block. same with cam too.

You can carefully tape up the piston top take up slack and also keep it from scuffing the cylinders, With a rod using cap screws (Bolts no nuts) You can hold block to the side or where piston will not fall back out, and instal a upper rod bearing in the rod, install carefully not nicking the crank and next we will get a little wild and crazy.

Install the cap screws by hand but tighten them deeper into the rod than the cap would allow. Be sure cam is not in block at this stage. With the bolts in the rod too far hold the piston pushing it toward the crank as you rotate the engine.

Watch each bolt head one cylinder at a time to see exactly where the bolt head clearance needs to be. mark that on the block pan rails with a marker across the pan rail. This helps prevent you from grinding or cutting the block in the places you do not need any extra clearances. By doing this in this way you will see exactly where the closest places will be. after you have a spot marked on the pan rails to line up with bolt heads, Nothing wrong with marking this spot with a scribe if preferred.

Remove bolts and install other rod bearing half in the rod cap and install the rod cap. Rotate engine slowly and watch to see if it clears, and by how much or if it does not clear and by how much. write on the pan rail or a hand drawn replica of the pan rails the appx amount you think it will need to be cut to get the .040 + clearances in all places.

Remove piston and rod and tape up or completely remove crank. To me it is easier to tape up.

.Clean oil off of crank rod journals and wrap with a tape to completely cover the rod journals for a pretection against the flying hot debris from the cutter or grinder.

Cut carefully but cut in only the places where you marked to be cut.

This will be a trial and error process and is a pain in the butt but it is necessary. For me I have found that a grinding round or triangle stone in a die grinder or high speed rotary grinder works better than using a carbide cutter. Maybe you will prefer the carbide. Hold the cutter or cutting stone straight and verticle as you cut.

After the pan rails seem to be cut enough for clearances, use a straight edge on your marks like a tri-square and eyeball on the bottom of the cylinder walls where notching them also will be in the same plane of travel of the rods and rod bolts. That will alce need to be ground or cut for clearances.

Is anyone starting to get an idea why we charge a few hundred to do stroker clearancing?

This process is a little quicker and easier if you own fixtures for each stroke size made by BHJ but they are costly.

The bigger the stroke is, the more material will need to be cut out of the block in three places for each cylinder.

4 inch stroke with a 350 or 400 is about the maximum. I prefer the 3.875 as the maximum.

If you are careful and sneak up on the needed cuting amount and cut in the correct places you will not hit wateer or oil. If you do cut through into water, cut farther and get it welded and do a bottom block fill with Hard Blok and you should have no problem once you again grind the weld so you have clearances you need.

Whew'

Ed

[skipjobe]

Thanks Ed I wish I was in Dallas instead of Houston I would bring this to you, but I will need to proceed here and your post will be a good guide for the clearancing issues.

[edvancedengines]

If I can help you in times of problems with it let me know. I have a few customers down that direction.

For doing your own engine in Houston I suggest to call The WopShop and talk with Bruce. He or any of the other shops can do you a professional clearancing job if that is what you need. I have no issues with recommending him, and to speak of him and Earl with much trust

By the way when you do brind on the bottom of the cylinders for clearance be sure to knock the sharp edge off and then lightly run a hone through. If you can't get a hone done, at least rub the bottom of the cylinder real good with a rough Red ScotchBrite to get rid of all sharp edges after any bottom cylinder bottom clearancing.

Ed