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Help with another 355 build!

11K views 61 replies 6 participants last post by  vinniekq2 
#1 ·
My friend gave me the engine out of his wrecked 97 Z28. I am going to put this engine in my 47 Olds. I’ve got the short block back from the machine shop, cleaned, bored .30 over stock pistons and balanced. I would like some suggestions about heads and cam. I would like to get near 400 HP from the engine using fuel injection. I have an 8.8 ford rear with 353 gears. I will be installing the rebuilt 4L60 trans from the 97 Z28 also. Looking at a driver with reliability in mind.
Thanks
 
#5 ·
Since I already have the pistons, can I change the CR? What size heads would be best? Can you pls explain more about the cam? Sorry if dumb questions, first build.


When you say "stock pistons",what type of pistons are you talking about?Do you currently have an EFI system,or,are you gonna purchase 1 ?
Flat top pistons. I would like to use the stock EFI system if I can.
 
#4 ·
If you don't know the part# for the pistons used,I would ck to see how far down inthe cylinder the pistons are.Hopefully they are not the "rebuilders pistons" w/ a short 1.54" pin hgt.Also,are you using the PCM & engine/trans mgmt from the 97?If using aftermarket EFI system,most controllers that come with them won't control the 4L60E.The 0411 controller from a 99 up would be the better option.Better tuning options & capability & you can control engine & trans w/ 1 controller.
 
#6 ·
Use 1 of the online DCR calculators to play around with different head chamber sizes & cams to see what your CR would be with different combos.For instance,with flat tops & a 64cc head,you are gonna be in the neighborhood of 10:1 SCR which would be borderline w/ iron heads,but,fine w/ aluminum.Cam choice will also play a role in your final effective CR (DCR) as well. Comp cams XR264HR would be a good choice for good streetable cam depending on what you HP goals are.IIRC,the stock EFI can support approx 400 HP.
 
#7 ·
The type pistons used are not the only determining factor in your final CR.Chamber volume,headgasket thickness/bore, piston to deck hgt. all play a role in your final CR.It's important to know how far your pistons are down the cylinder to determine the parts used to complete the build.If pistons with a shorter pin hgt were used,(1.540" vs 1.560"),your pistons could already be up to .045" plus the thickness of the head gasket used.Optimum quench,(the distance between head deck & piston top is .039 to .045.If your pistons are already .045 down w/o the gasket,you will want to keep CR relatively mild to avoid detonation.Proper quench helps to deter detonation & provides a more complete & efficient burn.
 
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#9 ·
Yes, I got the entire engine (with accessories still on it) , trans, wiring harness and computer. It was an LT1 aluminum heads, gear driven water pump etc. I believe the heads are small valve and would need to be reworked to be of any rear use. I think that the benefits of a new set would outweigh what I would get by having my old heads redone. RIGHT?????
 
#10 ·
You can measure the depth of your pistons with a depth mic,or,in a pinch,you can use a straight edge across the cylinder top & use feeler guages to get a somewhat close idea of the the deck hgt.You will wanna measure @ least on all 4 corners with that piston @ TDC.If the block hasn't been decked,the pistons should be .025" to .030 deep.If they are any deeper,the shop used "rebuilders pistons" with the shorter pin hgt.If so,changing pistons,or,decking the block would be your only way to correct it.If neither of those is an option for you,use a .015" shim gasket to get quench as tite as possible with what you have.This will give you approx .060" quench.The stock heads are not bad heads with some work.F'bird can give you best course of action what needs to be done with them,or,recommend a more suitable head for your goals.
 
#11 ·
Your engine stock,should have had approx 10.5:1 compression.Your aluminum LT1 heads have 54cc chambers & flow around 212 cfm as is with 1.94" & 1.5" valves.Some porting & cleanup.Maybe up the valve sizes to 2.02 & 1.6. They would probably easily support your HP goals.If the pistons turn out to be the shorter version,your CR will be slightly lower.The overbore will also give you a slight increase in CR.The stock injectors are rated @ 23 to 24 lb/hr.I can see you making 400 HP relatively easy & still maintaining good drivability.Getting a good PCM tune would also benefit you a lot.
 
#12 ·
Well, without having a depth gauge, and using a stright edge and feeler gauge, it appears they are re-builder pistons. So, I'm not able to do any work on my current heads and I would feel better purchasing a good set of heads along with a cam to match to get the 400HP I'm looking for. I believe it would money well spent.

I don;t know It depends on how much power you want to make. I don;t pay other people to port "re work" cylinder heads. I do it my self. Whether its best for you to port your LT1 heads or get and port a set of the LT4 heads or go aftermarket depends on what you are after and what you are willing to do.
F-Bird, see above.
 
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#15 ·
I don;t know It depends on how much power you want to make. I don;t pay other people to port "re work" cylinder heads. I do it my self. Whether its best for you to port your LT1 heads or get and port a set of the LT4 heads or go aftermarket depends on what you are after and what you are willing to do.
Yea, I understand what your saying. I really don't think that I have the ability, tools and or time, to clean up and port my own heads. I really wish that I did, it would make life much easier. From what I've read, on this forum and publications, a stock lower end can support 400 HP and your money ahead investing in a good set of heads with a cam to match. Would cleaning up and some porting on my stock intake manifold yield any additional benefits?
 
#13 · (Edited)
Vortecs flow approx 234 or so outta the box & are advertised to support 400HP as is,so'with your heads flowing 212,they will need some work.You do have slightly larger ports,so,IDK how much work we're talkin about.That being said,a set of aftermarket heads would definitely be a good investment,or,having someone rework yours.Get pricing for both & weigh the results.Keep in mind,that you having more flow & velocity is always a good thing.You may decide later to up your power requirements. If I had to guess & assuming you will have all the work hired out,I'd say you could buy a good set of heads for not much more than you'll have invested in yours.I would think that gaining another 22 cfm or so would take some substantial work.Not to mention new guides,seats,valves,springs,& machine work.You could probably sell yours to somebody.They're not bad heads.They just ain't gonna support 400 HP as is.
 
#14 ·
Joker, I appreciate all your assistance. Can you give me some guidance as to intake runner size, 185, 195, 210?? Chamber CC, 64 70??
I'm looking at these:
Brodix 1021007 Brodix IK180 / IK200 Small Block Chevy Cylinder Heads

or these:
http://www.summitracing.com/search/...delbrock-e-street-cylinder-heads?autoview=SKU

I understand that the Pro-Filer heads:
SBC 23 Degree Cylinder Heads
are very good but, according to another post on here, there is a substantial backlog on getting them.

Would any hyd. roller cam of between 220 and 250 deg. be enough to get me close to 400 HP with stock intake and injectors?
 
#16 ·
You will need a Gen2 head for either LT1 or LT4.I would use the smallest chamber volume I could get as close to your stock size.Even a 64cc chamber is gonna give up some compression.Your stock heads were 58cc.Camshaft selection is gonna be critical to not lose even more compression due to larger cams with late IVC points bleeding cylinder psi off.As far as port size,IMO,the 195cc would be good.You currently have 185cc intake ports.I'd rather have a 2nd opinion on that that tho to confirm.I'm not completely up to par on benefits & effects of the different port sizes & how they apply.Choose your head 1st,so you know what your SCR will be,then choose a camshaft with specs that will provide you with the proper timing events,specs,to your particular combo that will provide you with an optimum DCR.
 
#17 ·
While shopping & comparing heads & flow rates each 1,don't get hung up on maximum advertised flow.Some heads advertise the max flow @ high lifts.Compare flow across the board @ low lift,mid lift.If a heads best flow is only achieved @ max lift,that's the only time you will see the benefits.Your cam spends most of it's time @ low to mid lifts.You want a head that has good flow across the entire lift.Not just @ max lift.
 
#19 ·
For all intents and purposes, if I stick to Brodix, Edelbrock or Pro-Filer, shouldn't I be OK?

I'm looking at these heads from Pro-Filer:
SBC 23 Degree Cylinder Head, 11/32 Guides & Steel Seats
Intake Port Size: 195cc Intake Ports
Chamber Size: 70cc As Cast Chamber
Spark Plug Orientation: Angle Plug
Intake Valves: 2.02/1.600 Valves
Spring Package: Opt 92 .550 Lift,1.250 Single Springs, AL Retainers, Keepers Assembled ADD $50
Casting Style: Standard Cooling

Any thoughts?
 
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#21 · (Edited)
You have 54cc on your stock head.You wanna stay close to that to keep from losing compression.The E'brock Performers have 54cc & 170cc intake port vs your stock 185cc.They flow 242 cfm @ .500 lift.Lower lift #'s are ok.You also have Dart Pro 1's, AFR's.IDK what your budget is for heads.The E'brocks will support your 400HP goal,but,that would be about all.Most aftermarket LT1/LT4 heads have 54 to 58 cc chambers.IDK how the 170cc intake ports vs your stock 185cc would effect things.F'bird can maybe explain that better than I can.
 
#22 ·
This Trick Flow head looks like to me it would be a good candidate. #TFS30410008-M54. $1500. Not bad for a CNC chamber head. The TFS-30410010 is also good except it has 62cc chambers & since your already an extra .020 in the hole,you will lose some CR. $1460.
 
#26 ·
With a good valve job and a little porting they will do quite well.
OK---you guys got me considering using my stock heads. SO..... the engine had 170,000 hard miles on it. The owner really didn't believe in preventive maintenance ie. oil changes etc. I don't have the skills, or equipment, to do my own head work. If my heads need EVERYTHING, plus the performance work, angle valve job, porting etc., is buying new heads a better option or just get the old heads done? Any limitations on my cam selection by using my old heads?
 
#30 ·
The guy that AP mentioned @ Headbytes seems like he has some good stuff goin on.I would give him a call if you wanna rework your stockers.He's not very far from me,so,I'm definitely gonna give him a call.Decent prices if he does what he says.Shipping will prolly be the deal breaker tho.IDK if you'll save anything by the time you ship a set of heads both ways.
 
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