Critique the engine in my car/suggest upgrades
#1833547
05/24/15 11:44 PM
05/24/15 11:44 PM
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Joined: Oct 2005
Posts: 1,305 Lakewood, Colorado
herkamer
OP
pro stock
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OP
pro stock
Joined: Oct 2005
Posts: 1,305
Lakewood, Colorado
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Background, a little long so bear with please: I purchased a 72 Demon, 360 with 6 pack, 904, 8 3/4 with 4.10 gears that was "supposedly" set up to race with some minor work. Guy I got it from was not very knowledgeable as far as mechanical goes, more on that soon. Barely ran when I got it last fall. Rebuilt all 3 carbs, changed jets, and still a work in progress. It will start and idle fairly well now. Had air shocks and some home made shackles on the back, so removed those for SS springs and new shocks. In the process of changing those, found that the springs had no center pins. Figured I would take a look at the brakes and the driver's side was full of oil, massive end play and parts rolling around inside. Looked at the passenger side for adjustment and it was all the way in with no lock. Center section has a spool and had no thrust block or green bearings, so the axles were close to failing and falling out. All the safety items in the rear end have been fixed. Basically at this point I question how everything on this car was put together. I built a new 904 that would handle racing. Was in the process of swapping that, so only a few more bolts to get the engine out to inspect the quality of the build. It was leaking oil and had JB weld on the oil pan, so it needed to come out. Despite the constant daily deluge, got it out today and somewhat apart.
360 was supposedly rebuilt recently by the guy's dad who has now passed. He didn't have any detail. Cam is fairly lumpy for this altitude and it did seem to get along pretty good. 75 PSI oil pressure cold. After getting the valve covers off it seems the heads are 1978 360 heads. Looks as if they have had some port work done, and the smog ports plugged. I got one head off the block and someone has gone to the trouble of putting 2.02/1.60 valves in. Heads don't look as if they have been milled. Pistons have 4 valve reliefs and are .057 below deck. I don't have cc's yet to calculate compression ratio, but I'm guessing it would be lucky to have 8-8.5:1. Bores still have cross hatching in them.
The goal is to have a 12 or 13 second bracket car, still somewhat streetable and not break the budget. I got the car and a ton of extra parts for a screaming deal, and after fixing all the other things I wasn't planning on I don't want to invest $5000 if I don't have to. At that point, I will build a stroker if it's a total mess.
So considering all the above, what parts are salvageable? Swap pistons for better compression? Ditch the heads for better ones? Cam change? I had PTC build a new 9.5 converter that should be around 28-3000 stall based on the information I had at hand. I'd prefer not to have to send it back for rework if possible.
Fire away with ideas... Several pics attached showing detail of some things.
Matt 69 Dart Swinger 340 83 W350, Megasquirted with 46RH Old news: 72 Demon street/race mobile Latest: 70 Duster backhalf car and even more
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Re: Critique the engine in my car/suggest upgrades
[Re: herkamer]
#1833583
05/25/15 12:18 AM
05/25/15 12:18 AM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Sounds like the engine is stock... but since you plan on street driving it also.. I would fix the rear end.. either go with the green bearings(I like the green bearings) or set it up with the adjuster... on the engine..I would buy some cheapo zero deck pistons in the 10.4:1 compression area... if you cut for zero deck then use the .039 gasket for quench.. I port my own stuff most of the time so if you know how then clean up the heads with a valve job... cam... stay low on the duration.. something in the 225 at .050 with a tighter LSA like a 106-108 and advance it some.. the 6 pac stuff to me is just a PITA but if you like it and know how to work on it.. go for it
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Re: Critique the engine in my car/suggest upgrades
[Re: herkamer]
#1833604
05/25/15 12:42 AM
05/25/15 12:42 AM
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Joined: Oct 2005
Posts: 1,305 Lakewood, Colorado
herkamer
OP
pro stock
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OP
pro stock
Joined: Oct 2005
Posts: 1,305
Lakewood, Colorado
|
All mechanical issues from the front of the transmission back have been corrected. I did go green bearings and new brakes along with the rebuilt 904.
I forgot to mention that I'm at 5200'. Street use will be very limited, but I also don't want to get into putting a cage and all that in to race.
Edit: Looks like the pistons are Sealed Power 9:1
Last edited by herkamer; 05/25/15 12:50 AM.
Matt 69 Dart Swinger 340 83 W350, Megasquirted with 46RH Old news: 72 Demon street/race mobile Latest: 70 Duster backhalf car and even more
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Re: Critique the engine in my car/suggest upgrades
[Re: herkamer]
#1833615
05/25/15 01:02 AM
05/25/15 01:02 AM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Also.. I guess your gonna run some DR tires... so you wouldnt have to add anything
Last edited by MR_P_BODY; 05/25/15 01:13 AM.
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Re: Critique the engine in my car/suggest upgrades
[Re: herkamer]
#1834229
05/25/15 11:10 PM
05/25/15 11:10 PM
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Joined: Oct 2005
Posts: 1,305 Lakewood, Colorado
herkamer
OP
pro stock
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OP
pro stock
Joined: Oct 2005
Posts: 1,305
Lakewood, Colorado
|
I have Quick Time Pros so I should be good on the drag radials.
Been reading all day... Apparently the smog heads should be able to flow well with a little more work. Also looks like the KB 190 pistons will fit the bill with these heads.
Question now is at what point do you need to rebalance? The Speed Pro pistons I (think I) have are supposed to be 735 grams with pin vs 656 grams for the KB. Seems pretty significant to me. Pretty sure 79 grams needs to be accounted for somewhere.
Thinking some slight head work, new pistons and cam/lifters will be the ticket. Still open to ideas.
Matt 69 Dart Swinger 340 83 W350, Megasquirted with 46RH Old news: 72 Demon street/race mobile Latest: 70 Duster backhalf car and even more
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Re: Critique the engine in my car/suggest upgrades
[Re: herkamer]
#1834288
05/26/15 12:57 AM
05/26/15 12:57 AM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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I have Quick Time Pros so I should be good on the drag radials.
Been reading all day... Apparently the smog heads should be able to flow well with a little more work. Also looks like the KB 190 pistons will fit the bill with these heads.
Question now is at what point do you need to rebalance? The Speed Pro pistons I (think I) have are supposed to be 735 grams with pin vs 656 grams for the KB. Seems pretty significant to me. Pretty sure 79 grams needs to be accounted for somewhere.
Thinking some slight head work, new pistons and cam/lifters will be the ticket. Still open to ideas. You need to pull the engine down and get a idea of what you have... do you have a budget set up yet
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