Rebuilding my engine-Experienced advice please

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GWD
POC Newbie
Posts: 76
Joined: Sat Apr 07, 2012 11:33 am
Membership No: 11D200
Year: 1987
Model: Trans Am
Engine: 350
Name: GWD
Location: Sheffield
Location: Southyorkshire
Contact:

Rebuilding my engine-Experienced advice please

Post by GWD » Sun Jan 04, 2015 5:45 pm

Hi all!

The day getting closer when I'll pull the the engine out of my car.
I try to select part,calculate prices and basically make everything ready to hit the "order" button when the engine is apart.
But it's so confusing. I need your help guys.I've been spending days on internet to find the answers but it is still foggy for me.

What I have:

-1986 L98 350 CID. Alu heads,9.5:1 CR, 235 Hp (stock)
-Suffix code ZJS (Corvette)
-Hydraulic Flat tappets (non roller!)
-Holley 3310-6 (750 CFM) w/ Edelbrock perf. manifold (was TPI)
-Headman headers, 2x 2.5" stainless downpipes to 3" Y and 3" to rear box then 2x 2.5" tails
-Th700R4 autotrans.

(-low...ish oil pressure when warm ...approx 14PSI at idle with 20w/50 or 15w/40)
-smooth and quite enginge, no smoke, reasonable power.


What I want:
-Oil pressure gauge staying above half all the time
-Re-hone bores,Skim heads,(..may change valve guides)
-new pistons+rings
-New oil pump,bearings (con-rod,main,cam)
-New water pump,thermostat,block plugs
-all gaskets+ new valve steam seals
-new timing kit, new (mild)camshaft (may need new valve springs). (lifters are new )

I would like to get about 300 BHp W/O loosing fuel economy (best 20 mpg)
and I don't want to get lumpy ,wavy Idle at all.
As less modification as possible from stock.
I mean it's ok to replace valve springs with the new cam but I don't really want to go too far.I'm not building a trailer queen.
The car is a daily drive.It's got be smooth and quiet on long motorway journeys.Like it is now.
No drag racing ,No burning set of tyres out ,but fun!
Other keyword is the long lasting. It's got to last as long as it did with it's original parts.

Questions

1.Which Camshaft to choose. Any recommendation welcome.
It's hard to find the original (stock) specs,compare and understand them different duration times and etc.
I keep finding different infos abot stock L98 cam specs on internet.Manual ('88 Pontiac) says about L98:
Lobe lift-
-int .273
-exh .282 ? It looks to me more aggressive than mild street cam. Don't get it....
Why some cams costs GRANDS? Could it be good quality if I buy something for
130-150 USD (if its got the name Crane or Comp cams) ?
I was thinking about this one:
http://www.summitracing.com/int/parts/c ... /overview/
or this one
http://www.summitracing.com/int/parts/cca-12-262-4

2.Which Pistons to choose?
Which brand is good enough? Don't know them american names.. What type of piston do I need?
Forged? Aluminium? Hypereutectic?
Piston Head Volume?

Wich one would you buy from here?:

http://www.rockauto.co.uk/catalog/raframecatalog.php?ck Chevrolet/1986/Corvette/5.7 litre/Engine/ Piston

3. Type, brand for bearings, piston rings? Millions of selection on rockauto.
Is 'Sealed Power' a good name? One of their middle priced product?

4. What does the "reversed" water pump means?
Mine is turning Anti-clock wise. I believe it's stock.
Is it a "reversed" one?

5. What type of oil pump do I need? :
-High pressure
or
-High volume ?

6. Which one is easier:
-lift the engine out WITH tranny and separate when out
or
-separate engine from tnans and lift it out alone?

I think that's it up to now. If you have had the patient to read it through
and you still have a little bit to answer to any of the above questions, then please do!

Thank you guys!
Image
350 L98 from a '86 C4 with Holley carb, No aircon,no ecu,no airpump,no cat, Only pure engine and reliability!

Big Chief
POC Newbie
Posts: 65
Joined: Fri Dec 18, 2009 2:38 pm
Membership No: 88-001
Year: 1966
Model: most of them
Engine: 462
Name: Robin Gray
Location: Hounslow
Contact:

Re: Rebuilding my engine-Experienced advice please

Post by Big Chief » Mon Jan 05, 2015 2:14 pm

I think the best thing you can do is to give me a call at Autopontiac as you have too many questions to answer and too many possible engine problems, as this engine could have one piece rear main seal and roller lifter cam as standard if out of a Corvette.Roller lifter engine came in the Trans Am in 1987 and Corvette were usually a couple of years ahead. Have you seen the lifters? Does the engine have valve covers with attaching screws on the edge of the cover or or in the centre of the covers?

GWD
POC Newbie
Posts: 76
Joined: Sat Apr 07, 2012 11:33 am
Membership No: 11D200
Year: 1987
Model: Trans Am
Engine: 350
Name: GWD
Location: Sheffield
Location: Southyorkshire
Contact:

Re: Rebuilding my engine-Experienced advice please

Post by GWD » Mon Jan 05, 2015 4:43 pm

Hiya!
Thanks for your reply.
This engine has only one problem. It's getting worn now.
That loads of questions are all about getting the right parts.
The culture around cars in the USA is so big that millions of parts available for an engine,
depends on what you wanna achieve with it.
This is my first american car so I'm a newbie at this and select a part for my engine it's confusing me.
It's not like my everyday job when an EGR valve play up on an Audi then you phone Eurocarparts
or dealer ,give the reg or VIN...and the parts coming.
I wanna be right at the first place with this engine.

This engine is not roller type. I Have already changed the lifters.I saw them. The rocker covers have bolts in the centre.
All the informations I gave about my engine have been double checked.

The main problem is the cam. I would like to increase the power output of the engine.
Some very mild cam I'm thinking about. But some cost grands,so I lost my confidence to buy
something for 150 USD. I have never played with a 350 block before.
Just don't know which one to choose.

If you ever have done a mild cam fit to one of your customers car (350 SBC) and it worked well,
it'll be a big help if you tell me what were the specs of it.

I would be glad if you don't mind that I phone you ,but I don't want to disturb anybody at work.
I thought this forum is ideal to discuss also others can see it and get some info.

It would be a massive help if you can tell me which brand you have chosen from states to get good quality
pistons or bearings ...or cam... for reasonable money.Just names.

Thank you.
Image
350 L98 from a '86 C4 with Holley carb, No aircon,no ecu,no airpump,no cat, Only pure engine and reliability!

Big Chief
POC Newbie
Posts: 65
Joined: Fri Dec 18, 2009 2:38 pm
Membership No: 88-001
Year: 1966
Model: most of them
Engine: 462
Name: Robin Gray
Location: Hounslow
Contact:

Re: Rebuilding my engine-Experienced advice please

Post by Big Chief » Tue Jan 06, 2015 10:47 am

Have you built any other engine before as this engine is not one to learn on. As far as the parts are i think talk to Real Steel as they build them all the time and know what works well with what, their prices are very good and its not really worth buying in the USA. I buy from Real steel as they are the cheapest on quality proven products. I do not build Chevy motors any more as crate motors are cheaper, if we are talking Pontiac engines, this is what i do and can give more advise on power options.
If you are going to use a mild cam you will not get 300 BHP. This engine gives 235 BHP and a cam change is not going to give you 65 more BHP. We regularly fit high pressure oil pumps on this motor for low oil pressure and do it with the engine in the car if there are no other mechanical problems.

GWD
POC Newbie
Posts: 76
Joined: Sat Apr 07, 2012 11:33 am
Membership No: 11D200
Year: 1987
Model: Trans Am
Engine: 350
Name: GWD
Location: Sheffield
Location: Southyorkshire
Contact:

Re: Rebuilding my engine-Experienced advice please

Post by GWD » Wed Jan 07, 2015 6:36 pm

:thumb:
Image
350 L98 from a '86 C4 with Holley carb, No aircon,no ecu,no airpump,no cat, Only pure engine and reliability!

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