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Discussion Starter · #1 ·
Ok guys here goes, I'm looking for advice on either rebuilding the 1.9 in the 72 GT I just bought, or getting a used 2.2 from Gil at OGTS. I really want more power as it has an automatic tranny & Air/cond. It used 2 qts. of oil in the trip from Houston TX to Northern Calif. Redding area 2,300 miles and the plugs were clean? but it's cmpression read is front to rear 120/90/94/114 the two middle cyclinders reading the lowest (could've used the extra cooling jacket holes drilled as Otto sugguested) It's a hard starter, runs and idles ok and still has the crap Solex on it!!! I have a weber 32/36 and a new manta header to install, but am holding off on anything major now I've seen what the compression is!!! Being an ex aircarft mech. for 20 yrs. I want to everything I can the first time and be done with it for at least the next 5 yrs.!!! Gils price of $1,200 is fair for a used 2.2 (how many miles)??? or should I maybe do as Gil sugguested could be done do an head a valve job with hardened seats and pull the pan and hone and re-ring the pistons and install new rod bearing ( not an overhaul, but good for at least 5 yrs.) according to Gil!!! It was a major bummer to me to find out the Service manual says to drop the engine and Tranny out the bottom of these beasts!!! :( Gil said they will come out the top without the tranny connected but they wil have to be stripped completely of everything but the block??? ( makes me wonder how you move it FWD enough to clear the tranny imputshaft)??? Anyway if I go this re-ring and rebuilt head I will be putting a mild street cam in the head from OGTS as well with the Weber and header and I should have some more excelleration than now ( that of a tortise over hot sand) I want this car to be a daily driver with some Gonads, not something to race Rice Rockets off the light but something that can get out the way of an oncoming train at least!!! :cool:

PS: n I didn't ask Gil if he had any used 2.2 with fuel injection for $1,999 or the 2.0 used for $1,500 that's another option for me I guess?

Thanks for your replies in advance!!!
Ranger out
 

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I recently priced out a build up for alot more power using the 1.9 block and to be real honest if you can do the work yourself then a flat top 2.0 is probably the best bang for the buck. Parts and complete machining for the short block are around 950 and depending on the condition of the head you should be able to do a complete head for around 5 or 600. This would be a complete rebuild that brings alot to the table for around 1500. Depending on the way you drive and the number of miles you anticipate putting on it, you should be good to go for quite a while. This also depends on a few key pieces like the timing cover and pump being usable again.
 

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Discussion Starter · #3 ·
Thanx for the post Grant!! Question???

Grant so what your'e saying is buy the 2.0 short/or long blocK from Gil???
Or short Block 2.0 and have my head reworked??? I think your'e saying buy the used long block(what they list at OGTS) and have the 2.0 head reworked and leave the lower end alone??? The used long block lists for $800 from OGTS (if in stock)!!!

Thank You again for your reply!!!
Ranger out! :)
 

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here is the long and short on the short block.

pistons with rings 385
main bearings 95
rod bearings 45
gasket set 129
2.0 head gasket 34
timing chain 26
timing cover items 56
boring the block 80
grinding the crank 120
new pump and cover 120
RTV and paint 10

Ok I was close as that equalls 1100 for a completely fresh 9.25:1 2.0 short block. It depends alot on what you have and what you need. This is just my way of looking at it, but then again I like building Opel motors and I like having something I built under the hood. JM2CW
 

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Auto!

I have a '72 Auto GT too. The single item that makes them so sluggish is the 7.6:1 dished pistons. For a 1.9L rebuild the pistons must be replaced with higher compression ones to get decent power. THe standard motor is rated a 90 HP and in the condition of yours will be lucky to output 60 HP

So there are several ways to go that require decissions:

1) Stay at 1.9L and get some used, (or new) standard 9:1 pistons, replace bearings, put hardened exhaust seats in the head and generally fresh things up. Rated at 102 HP with the standard hydraulic cam - if yours is worn it will need replacing with new lifters as well. Use 36/32 Weber carb and modified standard intake manifold.

2) Use some new 3.75" Bore pistons (Chevy 265 CID V8 ones) instead of the standard ones. Rest of stuff the same as 1) - about 110 - 115 HP and 2.0 Litres. A slightly warmer ("torquer") cam would raise this to nearer 125 HP.

3) Get the 2.2L short block, fresh it up and use your 1.9L cylinder head with the chambers ground out to get the compression ratio down to 9.5 - 10:1 and unshroud the bigger valves you will need - Chevy 1.72 intake and 1.5 exhaust will work in this application. Don't under estimate the standard hydraulic cam though a warmer hydraulic can be used - remember you have an auto and the cam needs to take this into account. Around 125 - 140 HP with the Weber intake set-up - but you would be better off with more carburation. This set -up would give you far more low end torque to wake up thew auto - though you would probably have to fresh-up the auto with a rebuild too as it is as tired as the original motor by now. Fortunately it is a good GM TH180 auto and the rebuild kits are available from any good trans shop - just don't be too quick to tell them it comes from an Opel!

HTH
 

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Discussion Starter · #7 ·
Question for GT Jim, or any body!!!

Ok dished pitons eh? I also have a 1970 1.9 shortblock in a parts car, same bore and stroke according to OGTS, but more hroesepower stock (but weaker head? So I hear! Would this be a better block for a rebuild? If so are reccomending a 2.0 head, or rbuilding the 72 head for the 70 block? And will the 1.9 head accept the bigger valves of the 2.0/2.2 engine??? Full of questions I know, but you should know all I have to answer the question fairly!!!

Ranger out!
 

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actually I prefer the earlier heads as they are less crack prone but you only have 3 journals to deal with. Yes that head will accept the bigger valves but unless you are really looking at racing it the intake side is the one to enlarge. It's just my ideas but I would redo the earlier block and leave the later one for future use. JM2CW
 

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Discussion Starter · #9 ·
Thank you guys soo much for the advice!

Does anyone have a picture of the two different heads IE 1970 vs the 1972?
I take it the 1970 had flat top pistons vs the dished top as the bore and stroke are the same but the 1970 has 90 bhp vs 78 bhp for the 72 according the the engine spec sheet I got from Gil?

Thanx
Ranger out!
 

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Search

RangerRick,

Go to the top bar on the page and look for search and "click" on it. A small search box will appear - if you type "cylinder Head" in there and click on go all sorts of posts about cylinder heads will appear. Try a few more things like "pistons" or "racing motor" or what ever you want to find out about and the Search looks through the archived posts that are stored on this site.

Nobody's "2.0 Build Up " is worth a look and Greensmurf did a "Economical CIH Rebuild" thread that is also very interesting and worth a close look.

HTH
 

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Heads

RangerRick

The earliest heads had 3 cam bearings and 10 head bolts. The next head had 4 cam bearings and 10 head bolts. The last one had 4 bearings and 12 bolts. The best one to use is the 4 bearing 10 bolt head. Usually found in 71 and early 72. Nothing wrong with the 3 bearing heads, except the cam flexes in high HP racing motors. You can put hydraulic lifters in any solid lifter head as long as you use a hydraulic lifter profile cam. The heads from late 73 to 75 had induction hardened exhaust seats that cracked.

Look at the top of the head between the lifters for the aluminum plugs in the oil galley just above the cam bearings.

If you want an improvement in power that can't be had with just a cam, you can use the 42mm intake valves from a 2.0 and use the std exhaust valves (34mm) from the 1.9. All 1.9 heads had poor balance of intake vs exhaust flow. The exhaust will out flow the intake when everything is bolted up. No need to do ANYTHING to the exhaust side until you have do LOTS to the intake.

With the auto tranny you want torque, so you should port your intake manifold. Actually you should do this anyway!

HTH
 

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Strong, minimum dollar 1.9 rebuild

Here's what I'd do, based on what you already have and with cheap, but reliable and strong running rebuild result in mind:

1. Check your '70 shortblock with flat-tops for cylinder wear (ridge?) and mains/con rod bearing and journal condition. If crank journals and cylinder walls are OK, hone cylinders with cross-hatch pattern, clean up and re-ring flat-tops with new stock ring set and replace main and con-rod bearings. Replace rear main seal and assemble shortblock.

2. Check '72 head for valve guide wear and cracks. If OK, have valve pockets opened up for 2.0 valves and fitted with hardened exhaust seats (Jay-Lo shallow). Have bronze valve guides installed and sized, if necessary, and have valve guide tops machined, where necessary, for teflon "umbrella" seals. Re-assemble valve train, but without using the exhaust shrouds. Hint: if you have 2 heads, use only the intake valve retainers (with dimples and lighter of the two) off both heads in your valve train.

3. Check condition of timing chain guides at the front of block and inside your '72 timing cover and replace, as required, and use new timing chain. Check '72 timing cover oil pump for gear clearance, OP cover and relief spring/check valve wear, replace as necessary. Replace crank seal in timing cover. Assemble '72 timing cover (don't forget bolt inside WP cavity) and oil pan to '70 short-block.

4. Modify a '72 (12-bolt) head gasket with extra cooling holes at junction of #2 and #3 cylinders. Spray both sides of head gasket with Permatex Copperseal and let dry completely. When dry, spray both sides again, let it get "tacky", place gasket on block (don't forget coolant washer at right side timing cover) and immediately place head in place and torque down in 3 steps, 36lb/ft, 54lb/ft, 72lb/ft. Increase torque wrench setting to 74lb/ft and go over torque pattern one final time to verify that all are torqued properly.

5. Finish engine assembly, set valves, time it and fire it up. :D
 

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Best advise yet, and almost exactly what Gil said!

Otto I really thank you for your post & Otto Start you sold me!!! The only thing you didn't mention was the cam and lifters, I want a mild street cam and obviously I'll need new hydraulic lifters for the new cam!!! ;) The 1972 head is the better bet and so is hydraulic lifters that the 72 has and the 4 bearing gives the cam more support & less flex for sure! Question though about the 72 head to a 1970 block, same bolt pattern or did the 70 block have less head bolts??? :confused: BTW I have a 70 & 72 junkers that don't & never have ran since I've owned them! Either way looks like I will be two engine removals, but one will be in the shop while the other is still motroing the car hopefully! Hey, BTW again, I have an original one into 4 tip resonator on the 70, mount it to the back of the 2" 4 into one header & muffler or split the pipe after axle to just two tail pipes??? Already got the parts is why I ask, but don't want too loose the ponies I gain from the new pace setter header pipe either!!!

Dunk a shane!!!
Rick
 

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headwork

The 12-bolt heads have identical head bolt pattern to their 10-bolt brethren. The 12-bolt heads have two addtional bolts at the very front of the casting that screw into matching threaded holes at the front of the later timing covers . . . helps stop leaks at the head/timing cover junction. :cool:

That's why you need to use the matching later timing cover and headgasket, if using a 12-bolt head.
 

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achieving 9.25 compression w/o retarding cam timing

nobody said:
1100 for a completely fresh 9.25:1 2.0 short block. JM2CW
I am confused, How did you get 9.25 to 1 compression without milling the head and deck? or is this increased compression come automatically through
the correct piston selection?
 

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That is just by using the right pistons. They are the flat top 2.0s from OGTS and sell for 385 with rings. Pump gas should be no problem with them. Since most motors you can get or have now are a bit worn for just new rings it seemed like a simple choice and to get one bored they charge by the hole not by how big you make it. To be honest I have a good stock of blocks and none meet the specs for just doing rings alone, I have stock rings and pistons but alas no motor for them. Seems those days are behind most of us as the motors get more wear. Rick check the bores when you get a chance and you may be on the lucky side.

the prices I quoted are for local machine shops and parts from OGTS. I do like those guys no matter what, if ya don't believe me I can show you the reciepts.
 

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2.0 opel pistons verses chevy 265

nobody said:
here is the long and short on the short block.

pistons with rings 385
JM2CW
all things considered equal, wont the chevy pistons be equal or superior to the opel 2.0 pistons? I thought chevy was more economical and lighter , what is the advantage of opel 2.0 in this set up to chevy's 265's?

Does the chevy 265 result in lower compression?
 

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Cheaper is the critical factor to the Chevy pistons but then you get into pin size and deck heights. I always figure it's cheaper to get what you want first and not have so much wrapped up in redesigning it, unless your into that.
 

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Pros & Cons

The 2.0 L Opel pistons ( and rings) at $385 require only that the bock be bored to 95mm. The piston pins are the correct size for the Opel rods and the pin height is correct.

The 265 Chev V8 pistons are available for as little as $80 a set of EIGHT (cast - about the same quality as Opel 2.0L ) or up to $100 each for forged custom ones. The pin is larger that the Opel ones so the rod end has to be opened out to .927" for a press fit and there may not be enough meat left in the Opel rods if a bush for floating pins is wanted. The standard 265 V8 pistons are 3.75" or 95.25mm in diameter - slightly larger than standard Opel 2.0L ones. Pin height is pretty close to the same as the Opel pistons - but I am not too sure how close and it depends upon if the block has been decked or not. The Chevy pistons are flat top and have four valve notches and if they have an offset pin hole the correct four pistons need to be selected and fitted the right way around in the Opel block.

A lot less hastle with the Opel 2.0L pistons - a bit less money with the 265 Chevy ones (plus you get a spare set of four!)- your call ;)
 

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Discussion Starter · #20 · (Edited)
Rally Bobs two cents??? Por Favor??

Ok been awhile since I revisted this post! Got some great advice from OTTO, GM Jim and Nobody!!! Seems the 2.0 rebuild is the most popular advice about $1,000 the R&R is done yourself. Otto gave a great veiw at the freshenup! done while in the car. Here's what I've got on back burner right now. I can buy a set of new standard pistions with rings for about $300 for a refresh, obviously the oil pan can be removed with the engine still in the car to accomplish this (crossmember removed???) Anyway the compressions are lower than desired as stated, plugs are not oil fouled at all though; so I have more suspicion about the head and valve train. Oil consumption has almost ceased since I stopped a leak at the front of the cam area and replace the oil pump which was leaking out the weep hole in the housing. No shop wants to take on a freshen up do to liability, so I would have to go the full montey and rebuild her to a 2.0 to make it worth my money to even go there! Funny thing is she still climbs a hill faster than my V6 Dodge Dakota. I only drive this car less than 150 miles a month oil pressure seems to be about 3 1/2 and consumption nill so I think the lower end is good. So in closing would it be wise to just go new flat tops & standard rings with a good cross hatch hone and rework the head with larger 2.0 intake and mild torque cam? It helped getting the kickdown linkage adjusted right on the auto trans, but I still need some more tourqe as I live at 2,500 ft. and she is into the kickdown on the trans. a little too much for me. I think I still have it in me to do the refresh myself, the 2.0 will cost me maybe in the range of $2,000 in parts and labor if I have it all done by a shop I frequent.

And last but not least I have what seems to be a used 75 style Manta F/I system except for the computer control box I would love too strap on, however Gary's post about them matching the fuel injectors or frying the control box has me stumped on how to know what box I need??? This would also give me some ponies I could just bolt on.
 
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