EarlyC34me

This winter I am rebuilding the motor with my Dad. He is experienced but old school. I am looking at a very stock rebuild but will have many questions as to replacement parts recommendations and replacement suggestions.

I will be using many original components such as:
6239-1 780 Cfm Holley
Factory dual plane LT-1 winters intake
1182 forged crank
Pink rods
Period .100 Dome Forged L2304 pistons that were used in 1970 motors
487x heads(2.02 1.60) will get reconditioned
Original valve covers

For replacement parts such as gaskets, seals, bearings, timing chain set do these matter or are all pretty much the same quality? My dad would rescue most parts and i would just order everything new such as head bolts, guide plates, rocker studs ect.



The car has M20 4sp and 4.11 rear.

I know these are greenhorn questions but i want to do this correct.

Thanks in advance for the input

Crane Cams 110951
1.52 Comp Cams pro Magnum Roller Tip Rockers
Melling 10553 oil pump

TimAT

I've used Fel-Pro gaskets for years with no issues. Clevite Bearings, Melling oil pumps, Timing gears, everything from cheap to big bucks, as long as they were double row chain.
Your original covers might not fit over the roller rockers because of the cast-in drippers.
I'd get ARP bolts put in the rods and have them resized too.

rvazquez

Just make sure, if there is any machining to be done, that they stay away from those all important engine stamping numbers, some engine builders will tell you the engine block has to be decked, but that is seldom the case.
Good luck with your project!!
Regards
Roy

cv67

port the heads, keep the compression up so the cam works right

You may be able to grind the drippers out and use a thick valve cover gasket, may or may not clear to keep the stock look.

A well tuned 650 dp would be perfect for what youre doing;the 780 will be ok but think the former will be better

7T1vette

Why are you staying with the flat-tappets and cam? If you just want to keep the engine totally "stock LT-1", that's OK. Otherwise, consider installing a better cam with roller lifters and rockers. Much better all the way around, and you don't have to fool with the clatter & maintenance on the lifters, nor the requirement of zinc in the oil. You can go with a full synthetic from the start (after the rebuild) and minimize wear on that engine for another 150-200K miles. Performance will be better, too.

You can do 10.5:1 compression with those cast iron heads and still run on today's premium fuel. I don't think you can do 11.0:1 with available premium fuel without detuning the timing.

EarlyC34me

Thanks. I did not think about the drippers i will have to double check clearance here

I have a 650 on it now but going 90% stock LT-1 on the rebuild so the 780 vac secondary carb that was oem is how im going and building/tuning around that.

Not sure where i will land with compression but think 9.5-10,0 range with stock heads.

EarlyC34me

I'm shooting for originality mostly...the flat tappet and retro-roller has been pulling back and forth with me. Like I said in my original post my Dad is old school and basically said it would be a sacralidge not to run a solid lifter cam in an LT-1 motor. I started with the idea of the roller but have since caved. I have another motor i may do a roller set-up on and do a 383. For now, the budget dictates i finish what i have started with this. I agree roller is easy hp gain.

As for 150-200k miles i dont think the LT-1 with the gearing i have was ever designed for longevity.

Alex66

I also run 1.52 Comp Cams pro Magnum Roller Tip Rockers on These heads and they do clear without having to grind the drippers...


I wonder if the same Rockers in 1.6 ratio would clear as well, without having to grind the oil drippers of the LT 1 Valve Covers?!

EarlyC34me

Melling 55a or 10553? How do i select proper spring?

I had read debate on the gear quality on the 55a being lower quality and others saying for street use the 55a was fine. I know gofast said he builds with the 55a and the spring upgrade.

I had read other posts that say use the stock unit and swap out the gear if wear was present?

Thanks Tim

EarlyC34me

Great news. I'm going to run the 1.52's. The motor looks great what intake did you choose?

Alex66

My car is not a LT1 or I would have used the original Lt1 Intake... In this Picture you see a ported and disquised 2101, now I have a disquised a ED 7104 RPM Q-Jet on my engine. Your intake (if it is the original Winters snowflake) is great. Keep it with your original LT1 carb

Alex66

I would Keep the car as original as possible since it is a LT1... If you cant do yourself i would send of your heads to Brenzinzky racing (that's where i had mine done) to get more power out of them. They specialize in cast Iron parts and really know what they are doing. My heads flow really well for stock cast heads with big valves. But if you are a great mechanic than you might be able to do the porting work yourself. Raise your compression, mine is at 10.5 : 1. You have to rún high Octane fuel (what is not a real Problem in Europe) but it will run and Sound much crisper... But high Octane gas is a must.

cv67

If it were me Id run at least an honets 11:1, add a can of Torco per tank it really makes a difference in how it runs;so its a few bux big deal
Never had a cammed up low compression car "run" it just doesnt seem to work.

Not like its going to be daily driven for yrs on end..Ill get hung on the cross but love the solid flat tappets also they have a distinct feel and sound.

Alex66

I just discovered "Aral Ultimate 102 Octane RON" fuel, now i regret not running a 11:1 either.... With "Shell Ultimate 100 Octane RON", it would diesel when shutting of. I run my Timing at 35 - 36 degrees... Water is ok, but oil gets really hot, i am going to add an oil cooler!

Alex66

Can Somebody answer my 1.6 Ratio question, if they would also fit with the LT1 Valve covers???? Thank you, guys!

Dirty Dalton

I discussed oil pumps with Dr Melling... Ordered the suggested pump from Summit (new design). The suggested pump was too deep, the pickup contacted the pan. Summit was great, took it back, no questions asked. I can get you the particulars of the problem Melling, and the one that was fitted. (I'm old and forget stuff...)

You're replacing the pistons as you want to raise compression? I ask only because when I rebuilt mine the first time (1977) the bores were perfect, near factory new specs. Not many miles on it since then, and bores are still within factory-new spec. The pistons I used in '77 (+.001 dia) were reused.

Dirty Dalton

Not by me!

EarlyC34me

So i think i will be around 10:1 but will see when everything is together. It will be slightly higher than stock(9.0:1) as i am re-using the .100 70 domed pistons on the rebuild with the later 72 (487x)smog heads. I have read about Brenzinzky but Lorenzo's fast flow is about 5 miles from my house and is friends with one of my daughters friends dad. I have checked locally and Lorenzo is the performance head guy so thats were I will drop off the heads. If i was not going to stay original the higher comp and aluminum dart or afr would be how i would be headed.

EarlyC34me

Ed what pan are you running? Do you have power steering? What pump says suggested that did not work and why? What did you end up using?





I will be reusing the forged trw .100 domed 70 pistons.

7T1vette

Rebuilding an LT-1 engine and not taking it to pre-1971 specs should be considered sacrilege, IMO. I'm surprised that Dad hasn't scolded you on that one.