Author Topic: New heads or new long block?  (Read 15238 times)

Offline rich weyand

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Re: New heads or new long block?
« Reply #30 on: July 24, 2015, 03:21:45 PM »
Hey, English.  When you get it all together, you will probably find with that cam that when you have your foot in it that the stock TH350 (Your trans is a TH350), right?) will hold gears too long.  You will probably want to move shift points down about 500 rpm to get back into the beef of that torque curve sooner. 

If you find that to be so, I have the weight you need to modify the governor to do that.  Half-hour job.  I have one extra because I got a pair of them with another governor I bought for parts.  So, when it's all back together, let me know, and if you want to drop those shift points let me know and I'll send it to you.  No charge.  Stuff like that is easier for others to find over here, and it does nobody any good sitting in my parts bin.
Rich

"Working Girl": 1978 K-10 RCSB 350/TH350/NP203 +2/+3 Tuff Country lift

Offline English

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Re: New heads or new long block?
« Reply #31 on: July 27, 2015, 02:45:57 PM »
Wow, thanks for the offer, that's very kind of you. She's a manual though so no need.

Spoke to the vendor today, still going to be a few weeks before the blocks arrive. Very frustrating!

Offline English

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Re: New heads or new long block?
« Reply #32 on: September 02, 2015, 05:39:23 AM »
A container full of engines has finally arrived  8)
Taking the truck to the garage this afternoon for the swap. Fingers crossed it all goes smoothly

Offline LTZ C20

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Re: New heads or new long block?
« Reply #33 on: September 02, 2015, 09:54:30 AM »
Awesome!
LTZ Cheyenne C20

Offline English

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Re: New heads or new long block?
« Reply #34 on: October 10, 2015, 07:36:05 AM »
Whoa! Didn't realise it had been so long since I last posted here! I've had a hectic few weeks.

The new engine has been fitted, after the camshaft swap, without any problems (apart from the mechanic grumbling how hard it was to get into the engine bay- he normally works on drag cars!).

I'll admit I wasn't overly impressed with the performance at first, but I'm wondering if it just takes a while for the engine to break in, plus I don't think the wide ratio manual gearbox does it any favours. It feels a lot better now it's got a couple of hundred miles under it's belt. Feels just a little bit boggy at times when accelerating, I plan on spending more time tinkering with the carb. Initial timing is at 12 btdc.

But overall I'm happy with it, the best thing is being able to start first time, and it's so smoooooth!

Offline rich weyand

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Re: New heads or new long block?
« Reply #35 on: October 10, 2015, 12:52:57 PM »
Adjust the accelerator pump: https://www.youtube.com/watch?v=k-Nx5HEzvlY

Advance the timing further.  I am running that same engine at 17*BTDC with no knocking ever.  Timing is almost a horsepower adjustment: more timing gives you more horsepower, right up until knocking.  This is why modern cars have knock sensors -- so they can run the timing right at the edge.  If you get knocking, back off two degrees at a time until the knocking goes away.
Rich

"Working Girl": 1978 K-10 RCSB 350/TH350/NP203 +2/+3 Tuff Country lift

Offline English

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Re: New heads or new long block?
« Reply #36 on: October 11, 2015, 02:40:05 AM »
Adjust the accelerator pump: https://www.youtube.com/watch?v=k-Nx5HEzvlY

Advance the timing further.  I am running that same engine at 17*BTDC with no knocking ever.  Timing is almost a horsepower adjustment: more timing gives you more horsepower, right up until knocking.  This is why modern cars have knock sensors -- so they can run the timing right at the edge.  If you get knocking, back off two degrees at a time until the knocking goes away.

Perfect! The pump cam is what I was going to look into, but I didn't know I could change the pump nozzle as well. The video recommends I use a 25-30 size nozzle, whereas my carb (570 avenger) has a 31. Time for some more parts, thanks for the tip
« Last Edit: October 13, 2015, 02:33:17 PM by English »

Offline English

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Re: New heads or new long block?
« Reply #37 on: October 11, 2015, 06:54:59 AM »
Just had a thought- are the pump nozzles and cam kits available on the shelf in the US? My old man is on holiday there at the moment, if he could pick the bits up it would save a few dollars

Offline rich weyand

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Re: New heads or new long block?
« Reply #38 on: October 11, 2015, 09:47:26 AM »
That's the sort of thing we usually get mail order here. 

You can also order it over the net and get it shipped to the local store, then go pick it up.  So you could order it shipped to some O'Reilly's, Advance, or Autozone store he is close to and have him go in and pick it up.
Rich

"Working Girl": 1978 K-10 RCSB 350/TH350/NP203 +2/+3 Tuff Country lift

Offline English

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Re: New heads or new long block?
« Reply #39 on: October 13, 2015, 02:32:53 PM »
How's that for a quick turnaround- 'phoned the engine parts place on Monday morning, and the bits turned up today!
Got a 25 and a 28. Fitted the 28 tonight and went for a short drive, feels much better

Offline rich weyand

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Re: New heads or new long block?
« Reply #40 on: October 13, 2015, 08:59:20 PM »
OK, now you know you gotta try the 25, right?  That engine pulls a ton of vacuum, even compared to stock, and most engines people put a Holley on is cammed for horsepower and has a weak vacuum, so you gotta try things to get the tune squared away.  If less is better, even less could be better still....
Rich

"Working Girl": 1978 K-10 RCSB 350/TH350/NP203 +2/+3 Tuff Country lift

Offline English

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Re: New heads or new long block?
« Reply #41 on: October 14, 2015, 02:16:53 PM »
If less is better, even less could be better still....

I'm sure that quote sounds vaguely familiar...
Yeah I'll try the 25, I'm just doing it one step at a time. Will see how the 28 goes for a bit first.

Then I'm gonna have to look into the pump cam

Offline rich weyand

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Re: New heads or new long block?
« Reply #42 on: October 14, 2015, 09:26:08 PM »
IIRC there's a set where you get all the different flavors of pump cam in one kit.
Rich

"Working Girl": 1978 K-10 RCSB 350/TH350/NP203 +2/+3 Tuff Country lift