The 1947 - Present Chevrolet & GMC Truck Message Board Network

The 1947 - Present Chevrolet & GMC Truck Message Board Network (https://67-72chevytrucks.com/vboard/index.php)
-   The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board (https://67-72chevytrucks.com/vboard/forumdisplay.php?f=4)
-   -   Engine rebuild (https://67-72chevytrucks.com/vboard/showthread.php?t=580044)

Want2Run 05-13-2013 11:09 AM

Engine rebuild
 
Once the new concrete is poured in my new garage I plan on doing and engine overhaul. Id like to bore it .40 over, and put some new pistons, I figured Keith Black was a good way to go with those? and I figured 202 heads about 72cc-64cc so therefore id have about 11.5-1 compression, Harland sharp roller rockers, Comp Cams Double valve springs, Comp Cams Roller lifters, The motor now has a fairly large cam in it, (never had it out thou) should I still change the cam? and also, I will change the intake even though it is a stock aluminum intake, and all the other small things, Any suggestions or do I have a good list (brand name) to get the more horsepower I crave.

77ChevySharkBite 05-13-2013 11:38 AM

Re: Engine rebuild
 
the only thing I can really suggest to you as that it's best to look at your cam that's in it and get the specs on it, make sure with whatever set up you run that it all flows together, because if your cam doesn't match up right you'll still have power but if you get a good one, the gain can be quite nice.

Is it carbed, tbi, or fi? That'll help us out as well. If it's carbed look into also getting a better carb would help too. Distributor and new wires would help too, headers, and mufflers would help too.

As far as name brands I don't know the difference between brands other than prices.

Want2Run 05-13-2013 12:49 PM

Re: Engine rebuild
 
I have a Super Coil HEI Mallory distributor, headers, and true turn down flowmasters, and it has a newly rebuilt quadrajet 650 or 750 can't remember which. and I do understand if the cam matches it is much more horse but I'm saying if it does match with what I order should I change it is really what I'm asking.

77ChevySharkBite 05-13-2013 12:52 PM

Re: Engine rebuild
 
No if it works with everything you have, and gets you the power you want no need to change it.
Posted via Mobile Device

88Jimmy4x4 05-13-2013 03:50 PM

Re: Engine rebuild
 
11.5:1 ? On pump gas?
Posted via Mobile Device

77ChevySharkBite 05-13-2013 04:13 PM

Re: Engine rebuild
 
What's the max you can run on pump gas safely? 10.5:1 or can you push it with an 11:1? I'm not going to try and do it but I would like to know, I know for my motor I want to try and get at least a 10:1.

xrcr 05-13-2013 04:16 PM

Re: Engine rebuild
 
10:1 is plenty on pump gas

77ChevySharkBite 05-13-2013 04:19 PM

Re: Engine rebuild
 
Well I know pump gas varies, but with a 10:1, pump gas meaning running supreme in it right?

88Jimmy4x4 05-13-2013 08:10 PM

Re: Engine rebuild
 
10.5:1 is pretty much max
Posted via Mobile Device

LynnJr 05-14-2013 03:50 AM

Re: Engine rebuild
 
Bore the block as little as is possible.You won't gain much hp or cubic inches on a smallblock chevy by boring it out.You bore it to get rid of the taper and to even up all of the cylinders.
If its a 350 now and you want to feel the gains in the seat of your pants going to a longer stroke crank helps out much more than boring it out.
The next big gain would be a hydraulic roller cam or a set of aftermarket aluminum heads. which also allow you more compression on pump gas.
You also might look into swapping in some new rear end gears.

BigBlocksRule 05-14-2013 06:29 AM

Re: Engine rebuild
 
Keith Black hypers require special attention to ring gaps.
I had a set for a 383, decided to order some SpeedPros just to check, the KB's were like bricks when compared to the S/P's, much heavier.
Don't get compression too high, particularly with hypers - they shatter when the engine gets into detonation versus forged which generally survive a good bit longer. It doesn't take much of a load to put and engine built on the edge over into detonation. Even with a lumpy cam, 10:1 is probably max.
Go forged. You want more power, you'll want more with a bigger engine. Spray and hypereutectics aren't friends, you'll be looking for another block before long.
Why aren't you stroking it? You'll get more power from more displacement than any other tricks.

LynnJr 05-14-2013 11:27 AM

Re: Engine rebuild
 
For what it costs to go through a set of stock heads properly you can buy brand new chevy Vortec's or aluminum heads on e-bay ready to bolt on.

Want2Run 05-14-2013 03:47 PM

Re: Engine rebuild
 
Quote:

Originally Posted by 77ChevySharkBite (Post 6068793)
What's the max you can run on pump gas safely? 10.5:1 or can you push it with an 11:1? I'm not going to try and do it but I would like to know, I know for my motor I want to try and get at least a 10:1.

11.5 to 1 will run on pump gas and octane boost that is what my Nova motor started out with.. but no it wont run on pump gas, im not afraid to pay extra for the high octane fuel.

Want2Run 05-14-2013 03:49 PM

Re: Engine rebuild
 
Quote:

Originally Posted by BigBlocksRule (Post 6069938)
Keith Black hypers require special attention to ring gaps.
I had a set for a 383, decided to order some SpeedPros just to check, the KB's were like bricks when compared to the S/P's, much heavier.
Don't get compression too high, particularly with hypers - they shatter when the engine gets into detonation versus forged which generally survive a good bit longer. It doesn't take much of a load to put and engine built on the edge over into detonation. Even with a lumpy cam, 10:1 is probably max.
Go forged. You want more power, you'll want more with a bigger engine. Spray and hypereutectics aren't friends, you'll be looking for another block before long.
Why aren't you stroking it? You'll get more power from more displacement than any other tricks.

A new motor would be ideal.. ,but the kind of money a new motor is I don't have right now, my 355 in my nova has at least 525 horse, and it is not stroked. but other then those reasons I'd get a big block or a 383.

Rufton 05-14-2013 04:03 PM

Re: Engine rebuild
 
I would plug specs in an engine analyzer software program before selecting parts.

INSIDIOUS '86 05-14-2013 04:27 PM

Re: Engine rebuild
 
Quote:

Originally Posted by Want2Run (Post 6068319)
Once the new concrete is poured in my new garage I plan on doing and engine overhaul. Id like to bore it .40 over, and put some new pistons, I figured Keith Black was a good way to go with those? and I figured 202 heads about 72cc-64cc so therefore id have about 11.5-1 compression, Harland sharp roller rockers, Comp Cams Double valve springs, Comp Cams Roller lifters, The motor now has a fairly large cam in it, (never had it out thou) should I still change the cam? and also, I will change the intake even though it is a stock aluminum intake, and all the other small things, Any suggestions or do I have a good list (brand name) to get the more horsepower I crave.

10:1 compression is pushing the pump gas package without additives. And that's if your on top of your timing and timing curve
The factory aluminum intake has to go. The quadrajet has to go and your heads have to go. Why do you want it .40 overbore? I try and strive for as close to stock bore as possible.

Here's two nice combos. 2.02 fuelie heads and flat top pistons like speed pro hyperutectic and either some good condition stock rods it upgraded with new bolts (not a bad idea) or gm powders metal lt1/lt4 rods with new bolts(500hp6.5krpm)capable and a balance job on the crank. A comp cams 262xe cam or 268 voodoo for more rumble and power. A performer rpm intake with a Holley vac secondary on top. Use a nice clots roller chain and some hardened pushrods connecting to some nice roller rockers and don't get race car roller rockers they just cause you to spend more money and won't give you any return for it. Personally I would just go for comp cam magnum roller tip. And use a stock oil pump with a high pressure spring if you need to. This should net you close to 350-400hp.


Engine two. Here you have a different top end. Get a vortec intake and a Holley 750dbl pumper get some vortec heads and I would suggest having them blended but you don't need too. Have the same pistons and spec 10:1 compression since these are efficient burning heads. Use powdered metal lt1/lt4 rods with upgraded hardware and spec a voodo 268 cam with some good rockers. A cloyes timing Chain and a stock pump again. The vortec top end should net you 45hp at least guaranteed over the other engine I spec'd. I would say this should easily top 400hp. And if you parts match correct should come towards the 450hp side

Those are two combos that if your trans or rear diff aren't good that they will brake sometime under abuse
Posted via Mobile Device

wraprail 05-14-2013 06:16 PM

Re: Engine rebuild
 
Quote:

Originally Posted by Want2Run (Post 6068319)
Once the new concrete is poured in my new garage I plan on doing and engine overhaul. Id like to bore it .40 over, and put some new pistons, I figured Keith Black was a good way to go with those? and I figured 202 heads about 72cc-64cc so therefore id have about 11.5-1 compression, Harland sharp roller rockers, Comp Cams Double valve springs, Comp Cams Roller lifters, The motor now has a fairly large cam in it, (never had it out thou) should I still change the cam? and also, I will change the intake even though it is a stock aluminum intake, and all the other small things, Any suggestions or do I have a good list (brand name) to get the more horsepower I crave.

What motor are you starting with? 350? 305?
What year is it? 2 piece rear main? 1 piece?
What heads are you currently running?
72cc-64cc chambers don't equal "about 11.5-1 compression"
What is your budget?

Quote:

Originally Posted by LynnJr (Post 6069893)
Bore the block as little as is possible.You won't gain much hp or cubic inches on a smallblock chevy by boring it out.You bore it to get rid of the taper and to even up all of the cylinders.
If its a 350 now and you want to feel the gains in the seat of your pants going to a longer stroke crank helps out much more than boring it out.
The next big gain would be a hydraulic roller cam or a set of aftermarket aluminum heads. which also allow you more compression on pump gas.
You also might look into swapping in some new rear end gears.

Aluminum heads or/and a roller cam will allow more compression on pump gas?
Please explain..:devil:

LynnJr 05-14-2013 06:38 PM

Re: Engine rebuild
 
The original poster wanted the easiest way to more power.A hydraiulic roller will give him more area under the curve than a hydraulic or flat tappet cam.

The aluminum heads will take more static compression than cast iron before detonation sets in.

I didn't say a roller cam allows for more compression but in actuality it can.
Here is how the cam works. http://www.carcraft.com/techarticles...t/viewall.html

Aluminum heads dissipate (get rid of) heat much faster than iron heads. The rapid heat loss from the combustion chamber results in reduced combustion chamber pressures (heat equals pressure); similar to the effect that lowering the compression ratio which lowers cylinder pressure. When switching to aluminum heads you MUST raise the compression ratio to prevent a power loss. This is a good opportunity for our customers to take advantage of our computer calculated compression ratio service. This software assures them of getting the maximum power out of their purchase; it's a no-charge service for our customers.

Here is the link for the aluminum heads.
http://www.hughesengines.com/TechArt...sdoyouneed.php

LynnJr 05-15-2013 11:23 AM

Re: Engine rebuild
 
http://www.ebay.com/itm/Chevy-350-38...aa4861&vxp=mtr

Here is a set of aluminum bowtie heads on e-bay and when this auction ends he will post another set.You don't need anything over 210 cc's on a truck unless you are really into making power and spinning it up.
On E-Bay you have to read the ads very carefully and you have to watch the shipping charges.It is common to see aluminum heads go for $125 for a complete pair but the shipping is $350.
They set limits on much you can sell per month so some sell low and make it up on the shipping.Nothing wrong with that just a heads up if you will.
They also sell the 3.750 stroke cranks for cheaper than you can have your turned and polished for.Watch the shipping and keep away from the racing cranks as they are usually not as user friendly.
If you go 3.750 remember you will need a new flexplate and front balancer as well.
If your patient and have time to piece one together you can make some very good horsepower for a very reasonable price.
I have been bidding on rods and pistons for 2 months now and have set limits on what I am going to pay and stick to them.If I lose I buy something else I need and wait for another set of what I am after to show up.

http://www.ebay.com/itm/PRW-SBC-383-...b2d90e&vxp=mtr

http://www.ebay.com/itm/PRW-SBC-383-...b2d90e&vxp=mtr
This crank is brand new and is $148 to your front door.A machine shop will charge you $135 to turn and polish your old crank and you have to drop it off and pick it up plus tax.With this crank you use standard bearings.

BigBlocksRule 05-15-2013 11:43 AM

Re: Engine rebuild
 
^ Aluminum "BOWTIE" heads my @$$, those are Chinese knock-offs, comparable to ProComp - read it in the ad. Your crank link doesn't work, it's probably counterfeit Chinese crap as well.
Cheap ain't cheap if you have to have all the guides honed, ports modded and machined for off center bosses,head bolt holes, etc. and crank turned and trued to work.
And yes, I have experience with some of this junk. I fell for the cheap crap once or twice myself. Many experienced engine builders will run you out of their shop if you show up with this crap.
Cheap ain't good and good ain't cheap. Period. No different now that it's been for years.

LynnJr 05-15-2013 12:17 PM

Re: Engine rebuild
 
I was showing the original poster what was available.

On the heads they are the same heads use by Chad Spier and they are good street heads.The machine shop who puts them together has been in business since I was a little kid and its a big shop not a one trick pony.The heads are NOT assembled in china or australia.They are assembled in Bakersfield California by a reputable shop with a long racing history and modern state of the art equipment.Anything Chevy including trucks gets the word "Bowtie" added to it.
For the money they can't be beat.
Yes You can buy cast iron heads for $200 bare without seats and have a kid in Alabama with 6 month experience working for his uncle assemble them with a $300 kit and hope he found any cracks in the now well sunken seats between the valves and hope he hammered the seats in right but with my money I'll buy from a state where you have recourse if something is wrong and a guarantee.

On the crank its a Scat and I mis-linked it but they have been around for quite awhile now.Yes they are chinese but so is 80% of everything at Wal-Mart and 60% of Americans shop there every month.Your television is not made in America and
the cylinder heads in my Chevrolet truck have Hecho en Mexico cast into them.
If your local machine shop is building daily drivers and most are and they won't work on a Scat crank they won't be around long anyway.Yes he can buy a $4000 Wineburg Micro-Polished crank but do you seriously think that is what a 383 chevy in a truck on the street needs?
I have run these cranks and have had zero issues with them.
Yes I have read the posts on the internet were billybob and bubba put a 535 together with 0.125 over pistons after honing the cylinders with a berry hone and a used oil pump off the tractor and no machining or balancing work at all.They then tried spinning it at 14,000 rpm like a Reher-Morrison engine only to blow it up.I wouldn't blame that on Scat would you?

Here is a Chad Spier engine build-up for a smallblock chevy street engine running on pump gas.Notice which crank he is using in his build.


383 Chevy,
11.1:1 CR
SRP Pro series flat top pistons
Scat 4130 crank
Oliver 6" rods
UD Harold Solid roller... 255/263 @.050 .640"in/exh
Crower HIPPO lifters
Lunati ROller ROckers- 1.65int/1.6exh
Pro-Filer 210s done by Chad Speier ( 2.08/1.60 "econo" ported")
Holley 300-25 Strip Dominator intake ( gasket matched)
JDR performance carb (820-840cfm) 1.455" venturi x 1.75" baseplate
2" HVH Super Sucker spacer

Keep in mind, this is a pump gas street/strip motor. The dyno test was run on 93 octane. .

588hp @ 6500-6900 (varied by 1-hp(587) through 6900)
514ft/lb @ 5000

For a truck engine with unported heads I would cut the compression a half point and use a more driver friendly cam.

wraprail 05-15-2013 06:40 PM

Re: Engine rebuild
 
Everyone knows that Goodwrench Hecho en Mexico motors/ heads are total garbage.
Just like parts made in china..
Suprised you don't know this since you drive one.
Known Chad for many years. Great guy.
Thanks for the info on aluminum heads in relation to cr.
What site did you copy it from?
Later

LynnJr 05-15-2013 07:48 PM

Re: Engine rebuild
 
Wraprail
I included the links so there wouldn't be any confusion.When you click on the link it will take you to all the sources.I did this to avoid the confusion of a relatively new guy posting on a good ole boys forum.
I visited a new forum recently and was told new people without 5,000 posts can't be trusted.

I also copied Chad Spiers post above directly and it says he uses Profilers made in australia the same as the heads I linked the OP to.
I didn't think Chad was the kind of guy who would recommend a head on the internet then tell you his buddy/friend that they are really junk.I don't think your friend is doing himself any favors by telling different people different stories.

Maybe you could ask Chad if that was a misprint or he was using different heads and deceiving the rest of us? He posts this same stuff on 1320 dot com Yellow Bullet and Drag Race Results.Boy are those racers in for a surprise now that you let the cat out of the bag.

I am also surprised Chad posted that engine used a Scat chinese crank and has told you and everybody else that they are also junk and that everybody knows it?

I don't know who to trust anymore but I certainly appreciate you letting me know what these top guns really think!!!!!!!!

I know David Reher uses chinese rods as well and when you call they tell you that and actually sell them.
I was building a nice 406 and called Reher Morrison to ask what they put in their Super Series Small Blocks. He said "Scat rods. They're $XXX. You want a set?"

Imagine my surprise to find out on this forum about trucks that they are all junk and everybody knows it but they weren't telling me:devil:

I guy would think Lee Shepard just turned over in his grave.
I guess it just goes to show us that these big name race engine and head builders tell everyone a different story and really think the parts they use are all junk.

Thanks for letting me know what these big names are actually saying.

BigBlocksRule 05-15-2013 09:52 PM

Re: Engine rebuild
 
"Anything Chevy including trucks gets the word "Bowtie" added to it"
Bull$hit. Anything with a Bowtie cast into it is a Bowtie. Nothing else. Want me to run to the shop and take a few pics of heads and blocks?

I've bought stuff from Chad Spier, have no problem with him or his stuff, I've had a good bit if dialogue with him. When he posts on here that the same exact heads you linked are his castings, I'll believe it. Those are NOT profilers, although the ebay castings and Profilers both cross the Pacific to get here. Holy $hit, what a claim to fame - "these heads are nearly identical to ProComp" - directly from the ad. I'm sure Chad searched extensively before he picked his source, I have that much confidence in him.
I've used Scat cranks and rods in a lot of builds, have no problem with them. If that's what's in your link, that's fine. Fix the link so we can see. $150 for a crank to your door doesn't sound like even the cheaper Scat's I've bought direct.
There's also a lot of different offshore places that cast and forge parts.
Folks who shop price at all costs are the ones who drive the sweatshop labor market overseas. I don't have a choice about where my electronics are made. I do have a choice about where my engine parts are made.

Don't go to Harbor Freight to buy something that you need to be able to depend on.

LynnJr 05-16-2013 02:00 AM

Re: Engine rebuild
 
BigBlocksRule
The original poster is building a motor for his truck.He didn't mention a 6500 rpm convertor or 5.13's or even running a single Dominator.
I took from his post he wants a nice running street motor to rip through the gears not a finicky race engine.
The heads I posted a link to are perfectly fine for his purposes as they offer more intake volume than a stock chevy head and less than a race head and they are well put together by a competent shop.
For some reason everyone here thinks these are pro-comp heads and they are not.They flow similarly which means they are better than 99% of the heads sold on chevies for the last 50 years.
The machine shop putting these heads out there is not making wild claims and they shouldn't thats my take of his ad and from knowing him personally.

The crank is likewise a cast crank perfectly suited for a nice street driven truck motor.Again He is building a truck motor and doesn't need to spend gobs of money on a crank that will rarely see any rpm..

You guys seem to think if he builds a 383 using these heads his motor will let loose.What are you basing this off of? Do you know how many sets of these heads are running around? Did they all blow up?

Everyone is entitled to their own opinion but they are not entitled to make up there own facts.

Most of the older halfway decent breathing chevy heads don't have hardened seats and the seats are sunk halfway to china.If you find them for sale the guides are pinned or need pinning and they need seats.

I will assume you know how much this type of work costs and he will have old pinned heads at best that cost more than new aluminum heads.I also never suggested that he buy cheap parts.I let him see what can be had without breaking the bank.He can buy spread ports if he wants.

Chad made the recommendation on my heads for my 496 talldeck and I value his expertise.He is running Australian castings and has posted pictures of his work on several forums I frequent.He isn't as critical as those posting here are and he is a professional head porter who is known as being quite good at what he does.
Maybe you call tell me what he thinks of Pro-Comp? Does he use them?

I don't know why you would run a set of chinese rods and a chinese crank in your motors as everybody here knows they are junk.I saw it posted on the internet so it must be true right? I notice you didn't respond to that posters comments and was wondering why?

Please note that I posted what one of the most well respected chevy engine builders of the last 40 years told me on the phone.I don't want anyone to trust me I want them to call Reher-Morrison and find out what they think for themselves.I then want them to post here that I am a huge liar so the whole world wide web knows I wasted my time here trying to pull the wool over the original posters eyes and got caught.

Until one of the experts here calls and posts what reher-morrison has to say about Scat rods in a street truck motor I am definitely not drinking the Kool-Aid.

I would like to see you post your list of recommended parts for the original; poster.
Crank,Rods,Pistons,Cam,Heads,manifold,carb,convertor and gears.


All times are GMT -4. The time now is 10:44 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2026, vBulletin Solutions Inc.
Copyright 1997-2025 67-72chevytrucks.com