5.7 engine build

[Scott Danforth]

With vortec heads, you can run up to just under 10:1 on 87 octane. a bit higher on compression with 91 octane

running flat tops, vortec heads, and a comp XM268H cam, I was running 36 degrees total advance. Only pulled the motor to go bigger

I agree, balance the whole rotating assembly

 

[1979 Quartermasters]

Ok guys, got the report back on the crank and block. Crank is straight and not in bad shape. Polish only. Block is good. No cracks and passed pressure test. Bores are with in spec and two are slightly out of round. They also suggested a line bore. Some wear on the main caps. I thought I would have it bored .030 over any way. As far as getting to zero deck, the shop said I need to reassemble the rotating assembly and find the deck height. Is this how it's done? I don't know if I have all the terminology right.

 

[alldodge]

In my opinion only, if a machine shop said they had to reassemble the block to determine the deck height I would say thank you and take it to another shop. The center of the crankshaft journal, is the center. Now add the length of the rods being used and then the height of pistons and you have piston height in reference to the deck. Measure everything and slack off about 0.005 and go with it. Agree it is easier to determine it assembled, but a good machine shop already should have the factory dimensions, but this is how IMO those that don't build engines do it.

Again cannot determine the deck until pistons, rods, bearings and line bore is done.

If I was going to build a motor even if the journals check out I would still want to have the crank turned to .010 under. The reason for this is to make sure the surfaces are 100% true. If the journal is even the slightest off true, the motor could put a 100 hours on it and then spin a bearing.

Lastly to achieve the best bore it should be done with a torque plate

 

[Scott Danforth]

Every machine shop I have ever used, verified the crank center to deck, measured the rods, measured the pistons, and then determined deck height. Then machine accordingly to get to desired deck height

 

[flipbro]

79 another thing you need to take into consideration is stock pistons have a pin hieght of 1.560 thats center of piston pin to top of piston. Most of your cheaper rebuild pistons are only 1.548. So when deaking for quench you have to know piston pin hieght of the piston u are using...

 

[1979 Quartermasters]

I'm having some difficulty finding a D dish forged piston. I see RD, Flat tops with reliefs.........overwhelmed. Wouldn't feel confident in spending $5- 600.00 based on what i have learned. Anybody have part specific recommendations with links?

 

[Scott Danforth]

KB pistons, Seal Power, or JE all have proper pistons

 

[flipbro]

Why run Forged? With forged they run alittle loser in the bore. That causes some light piston slap till she warms up. Not to mention cost. Forged is more of a high hp application IMHO. You won't find a cheap D dish piston and if you do let me know. What you can find is a cheap flat top 4 valve relief hyper for around 150 that's got the pin at 1.560

 

[1979 Quartermasters]

Thanks for input. I really don't know what the best plan is. I'm not necessarily looking for "cheap". Although, I do want a strong 350 hp, torquey motor that is reliable and can take some abuse when needed. I don't mind spending a little more than "cheap" if it's going to help in thoses areas. I guess I will call JE or KB tomorrow and get them to help me select the proper piston. You guys have been very helpful in educating me. I like the 9.4 cr .040 quench and Vortec head.

 

[Scott Danforth]

Here are a few I found quickly with my phone. You will need to verify relief volume, bore, etc

http://m.summitracing.com/parts/wis...ctTJeAaR3F_KFdIzcHDk3gZpBR4xqe6OpYaAilZ8P8HAQ

http://www.lunatipower.com/Product.aspx?id=1284&gid=233


Here is a good read


http://www.chevydiy.com/big-inch-chevy-small-block-building-guide-pistons-rings/

 

[1979 Quartermasters]

Thanks Scott

 

[1979 Quartermasters]

Just found these puppies. Wiseco KP421A3. I haven't figured out how to get a direct link. Is this over kill. The write up says they are design to sit flush at 9.015, so if i deck to 9.015, .040 head gasket to get .040 quench with 64 cc vortec heads. Should be 9.83 cr. Am I getting it?

 

[Bondo]

I'm having some difficulty finding a D dish forged piston.
Is this over kill.

Ayuh,.... Ya don't need Forged pistons,...

Hypereutectic fit the bill nicely, 'n are much cheaper,... Much better than plain ole cast,...

What ya really need to do, is find yerself a Machinist, 'n develop a relationship with 'em,....
'n Don't buy anymore parts, til ya Do,....

 

[1979 Quartermasters]

K. That's what I'll do. Found an engine builder/machinist that comes highly recomended. I'll go and introduce myself. I have not bought anything yet.

 

[flipbro]

X2 Well said Bondo.

 

[1979 Quartermasters]

Update: Went and talked to engine builder and I decided to let him build the engine. He has dyno, will balance and blue print, give warenty and build it pretty much the way you guys are suggesting. All this for not too much more than it was going to cost me. Thanks for all your help in educating me so I could go in there and understand what he was talking about.

Couple more questions. This block is from a 1998 GMC. Will it bolt on to driveline and will all the externals bolt on as well.

I will be switching to an electric fuel pump and would like it legal and safe. Is there information on what I need to achieve this.

As always.... Thanks

Ken

 

[1979 Quartermasters]

I will be switching to an electric fuel pump and would like it legal and safe. Is there information on what I need to achieve this.

Turns out there is a whole lot of info on this in the search function........go figure.

Ken

 

[sub2010ss]

There's a lot of advice in this post. As exciting as it is to build an engine for the first time I'm glad you ended up taking it to the shop. If hate to see you doing half of the things you have planned only to miss a measurement or two and give contact somewhere inside of your engine.

My thought on this, 350 hp is not a difficult number these days. I've built more of these 350's than I can count including a few dozen hot rod or race engines. Your shop should take good care of you.