What type of cam would be in my stock 350

[kikkegek]

hi guys,

what type of cam would be in my stock engine?

info:
castingnr: 14088548

my car is a K20 Suburban from 1986. I think it is still the original engine.

my VIN info:
1G8GK26M0GF130924

1 us bUILT
G General Motors
8 Chev MPV
G GVWR Range in pounds - 8001-9000 - Brake System HYD
K Conventional Cab 4x4, incl Blazer, Jiummy and Suburban
2 3/4 Ton
6 Suburban
M 5.7 V8 4BBL HEADY DUTY 4 bolt main DIV.Usage C,T Produced in U.S.
0 Check Digit
G Model Year 1986
F Plant Flint "Chevy"
1 Production sequence (en alle getalen hierna)
3
0
9
2
4

and my options list:

[BigBlocksRule]

Flat tappet, stocker type.

[kikkegek]

Originally Posted by BigBlocksRule

Flat tappet, stocker type.

he thanks, but how do you know and how can I find out?

[BigBlocksRule]

You'll have to pull the cam and send it to someone with a "cam doctor" that can measure all the aspects (lift, duration, etc.).
Why do you need to know?

[cory d]

around 200 duration at .05, lift of around .400and lobe seperation aroud 114. reeeeeeal mild economy stuff

[kikkegek]

well, I like to know, because I want to know if it will be worth it to swap it for something else.

I have changed some stuff on my car and think a different cam might help:

1. swapped TH400 for a 4L60, so cruise rpm are now 1900 in stead of 2900 rpm

2. took all the gasoline stuff of and fitted a IMPCO 425 propanecarb

since we only cruise and dont do any heavy hauling, except ffor maybe a very light trailer in the future in summerholiday, I want to check if changing the cam will help me?

Since our Suburban is a K20 (3/4ton) and has a high gear ratio and trailering package (Z82) you expect a cam with low end torque. but its also a Suburban that came originally with all the californian-smog-stuff, so maybe the cam might be adjusted for polution. since I dont have any clues about cams yet, I asked over here.

If I would take out the cam I be able to find the serial on it, wont I? wont that tell everyhting?

Its our daily, so when I open her up, I wanna do instant swapping so sheś on the road again one or two days.

[BigBlocksRule]

Most stock cams don't have anything on them until you get to the roller stuff, most of them are marked.
Can you check to see if your block is set up for roller lifters?

[kikkegek]

Originally Posted by BigBlocksRule

Most stock cams don't have anything on them until you get to the roller stuff, most of them are marked.
Can you check to see if your block is set up for roller lifters?

when the heads were changed they told me they also changed the "hydraulic lifters" because they were old. so I guess I have hydraulic lifters.

heres a picture with the valve colver off. does that help?

[BigBlocksRule]

Looks like '87 was the first year for roller lifters. If you can shine a light through any of the head drainback holes, you should be able to see the tops of the lifter bores are machined flat and look for the spider hold-down bosses are in the middle of the lifter valley. Chances are you're flat tappet.
As long as you don't get radical, you can get a better cam for your engine. Newer oils are low in zinc, the newer roller motors don't need as much but there are still plenty of 'em on the market that are fine. New cam break-in procedures MUST be followed to the letter. Research oils and cam break-in.
As long as you're not going to overhaul the engine, there's not really any good reason to spend the money to upgrade to rollers, just watch what oils you use.
I am not familiar with propane - I'd bet you could find somebody on the net that knows what's up with that fuel and cam selection. I'd keep it small, under about .475 lift. Best towing cams I've used were about 210 - 215 duration with 114LSA.
If your tranny isn't computer controlled, it's a 700R4...

[kikkegek]

Originally Posted by BigBlocksRule

If your tranny isn't computer controlled, it's a 700R4...

he thanks man for all the info. They showed me the old lifter als they are flat. I know remember.

so flat tapped they are. the engine is old, but running fine. Is there a big cost difference in rollers and flat tapped? I might rebuild the engine within the next 2-3 years. So would rollers be a good investement?

problem is I cant find any real good info on the cam selection for propane.

found some info in my cam search:

Here are some basics for choosing a cam from your range:
Large cars: Use short or medium duration, exhaust can be longer. Wide lobe seperation is better.
Small Cars: Use long intake duration, exhaust can be longer. Lobe center seperation can be short.
Propane and Natural Gas: Use short or medium duration single pattern. Wide lobe seperation is required.
Trucks: Use short duration. Wide lobe seperation is better.
Nitrous or Supercharger: Use long duration. Wide lobe seperation is required. Supercharger compression must be lower than shown in the guide.
Turbos: Use short or medium duration, exhaust can be shorter. Wide lobe seperation is required. Compression for turbos must be lower than shown in the guide.

but I dont know really how this info helps me. Summit already offers several choices and lifts for each type of the cams...HELP?

as for the tranny.
http://en.wikipedia.org/wiki/Turbo-H...al_Description

In 1990, the Turbo Hydra-Matic 700R4 was renamed the 4L60. Under the new designation, the "4" stands for the number of forward gears, the "L" for longitudinal applications (rear-wheel-drive), and the "60" is the strength rating (less than the 4L80). "60" is the relative torque value.

since I have a 1991 model its a 4L60....

after 1992 electronics were added and they changed it into 4L60-E

[BigBlocksRule]

Yeah, I forgot they semi-renamed it to the 4L60, tranny shops refer to all non-electronics as 700's.
I'd probably leave well-enough alone and run it as-is. Meantime, find a 4-bolt roller core engine and start on that. I buy 'em for $150 - $200. This gives you a crank, set of rods and heads, everything you'll need for the new engine. Rebuild that one and swap it out as soon as you're finished. If the current engine is still running, you can sell it to recoup some of your expenses.
What kind of intake is on it - TBI or carb? I assume you've used an adapter to add the propane rig?

[kikkegek]

intake is the factory dual plane right now. will swap later for a single plane Edelbrock torker II I got second hand.

problem is that engines arent as common over here as they are over at your side of the ocean. And I dont have the space to build my own engine.

but just for knowlegde. 87+ engines are rollers?

[BigBlocksRule]

I have a guy in London that ships tons of bare blocks from here to there and he has quite a market, I'm sure they're high. If you have access to a good machine or engine shop, you can learn exactly what to tell them regarding machining so you'll come up with a good engine. If you rebuild it, you can reuse your rods and pick up a Scat cast stroker crank and make a noticeable power increase.
Before you add a cam, run a compression or leakdown test. If all the cylinders are sealing well, you're good to go. If you have a lot of blowby, I think it's best to leave it alone until you can get a complete overhaul.

[SSC's76]

Originally Posted by kikkegek

intake is the factory dual plane right now. will swap later for a single plane Edelbrock torker II I got second hand.

problem is that engines arent as common over here as they are over at your side of the ocean. And I dont have the space to build my own engine.

but just for knowlegde. 87+ engines are rollers?

Nope not all roller cam engines until 96. the blocks are capable of using factory roller cams late 86 and up but not all the engines came with roller cams.


Posted from 67-72chevytrucks.com App for Android

[Pop's C-10]

stick with a dualplane intake

[INSIDIOUS '86]

Ditch the torker II. The single plane intake will do you no good till 350hp and the torker II is the worst single plane made.

If you call comp cams you can give them all the specs of your truck and what you want to do. They will match you with a cam that's perfect.

Rebuilding a motor with a roller cam already in makes it a lot cheaper as the old rollers can still be re used instead of an extra $300 in new roller lifters. Wheras a flat tappet cam is only $200 with cam and lifters
Posted via Mobile Device

[kikkegek]

guys,

thanks, but lets not forget.

I drive propane, not gasoline.

so all the stuff that makes sense for gasoline, does not automatically make sense for propane. Propane is already gaseous and gasoline is not. propane benefits from open plenums with lots of room so it can flow freely. the speed that gasoline needs, so it wont fall out us suspension, does not affect propane.

that is why I bought the torker II in trhe first place.

basic advise for propane is to go single plane and one size bigger then gasoline. which the torker is compared to the performer from edelbrock

I have sent crane and comp an email and asked them advise for my setup. hope they can handle the propane question.

I'll report back here.

and yes, I need to check my CR...still didnt get around to doing that

[BigBlocksRule]

I understand about the carb signal and single vs dual plane, but dual planes still have higher velocity for cylinder filling.
I don't think it's worth swapping it for a dual plane, there can't be that much difference, I'd keep what you have and give 'er hell.

[kikkegek]

the higher speed is true when you have a 2 or 4 barrel setup. But the IMPCO is a one barrel setup. The dual plane will cause the cilinders to always suck on only 25% (one throttle valve) or 50% (two valves) the same time. Where in a single plane setup the the cilinders will have 50% (two valves) or 100% (four valves) to suck on all the time.

I have read in a lot of places that propane benefits from that.

Also propane expands more then gasoline thus benefits from a bigger plenum.

here is what Jay Storer says about intakes and propane