Street Engine On The Cheap?

[ghcoe]

Ok, I have a idea for a cheap street engine. I just need something that is peppy on the street, but not daily driver unfriendly. A little bit better fuel economy would be good too. Of course this would be a economy build to see what can be done on the cheap.

I have a machine shop that can do the work I can not do myself. This is the build I have in mind.

Going into a stock FI 1975 Opel Ascona.

-Stock, used flat top pistons-If cylinder bore is in spec. (I will need to source these though)
-Recondition rods
-Crank checked and balanced-honed if only needs honing
-Rod/Piston weights balanced
-New Bearings-main and rod
-New Timing chain and guides-prefer chain with master link (Know of source?)
-Cam sprocket modified for degreeing cam
-2.0 or 2.2 intake valves installed
-Cam reground to a street performance spec and recondition lifters
-Port intake side of head-As per Bob's thread
-Mill head to build compression. Not sure how much though (Ideas for this build?)

I will be trying to save some cash by sourcing parts on the UK/GR ebay and forums. Dang that VAT and shipping costs though.

Hoping this will liven the engine up a bit.

I will be adding larger 2" exhaust and a megasquirt with a Ford EDIS system at a later date.

This car may see some autocrossing, but just for fun not hard core competition.

Trying to get a fun build for under $1000.00.

George.

[wklopf]

On items shipped out of the European Union, you should not have to pay the VAT or what ever it is called in the different countries. Shipping is a different matter. Bill

[RallyBob]

Originally Posted by ghcoe -Stock, used flat top pistons-If cylinder bore is in spec. (I will need to source these though) -Recondition rods -Crank checked and balanced-honed if only needs honing -Rod/Piston weights balanced

If you are using old pistons, leave them as they are. In order to recondition the rods and balance them, they need to have the pistons pressed off. Most likely you'll do more damage to the pistons removing them than you would gain trying to balance and blueprint everything. As long as the rods and pistons are from the same engine (weight matched from the factory), and the rods never had a spun bearing, you should be fine with them 'as is'.

-New Timing chain and guides-prefer chain with master link (Know of source?)

Check with OGTS, I spoke with them last week about this and they were trying to source some.

-Mill head to build compression. Not sure how much though (Ideas for this build?)

Depends on how much compression you want. Flat tops are typically about 8.4:1 'true' compression with a stock, unmilled head. If you deck the block .010" and mill the head .050", you'll end up with approximately a 9.5:1 true compression ratio. This will be affected by the height of the valves in the chamber, the size of the valves you use, the head gasket thickness, etc.

I will be trying to save some cash by sourcing parts on the UK/GR ebay and forums. Dang that VAT and shipping costs though.

You should *not* have to pay any VAT for anything shipped outside of the country of origin. You might need to clarify this to the seller however, to remind them.

[yellaopelgt]

Instead of milling the head...look for a 1.5...might be a cheaper way to go...especially since your putting in big valves. Just a thought....The amount of effort in getting the timing on square after a milling isnt a fun process.Toss a big cam in there...And find a 75 distributor......It'll be worth it..

Joe

[RallyBob]

Originally Posted by yellaopelgt Just a thought....The amount of effort in getting the timing on square after a milling isnt a fun process.

In truth it's pretty easy to do. I modified the cam gear for my 'stock' 2.2 last night, it took less than 5 minutes to do on a drill press. I'm not even going to check the cam timing when I assemble the engine. I did some quick figuring based on how much the head was milled (cam is retarded by about 2.5 degrees) and stuck in a 4° bushing...good enough for me! A little bit of advance is preferable for street driving.

Toss a big cam in there...

Not a good idea with stock Opel fuel injection as it will barely idle, and will lean out a lot on the top end. If he does the Megasquirt then it's viable.

Bob

[ghcoe]

Thanks for the info.

I was thinking that it should be pretty easy to source stock sized pistons and cheap. Most people rebore their motors and there is not much demand for stock sized pistons. If they do rebore their motors I would assume they would need their rods. Are the piston pins durable? I would not want some pin slap shortly after a engine install. Can the piston/rods be rebored to a common pin and just weigh each item separately or is it better to assemble complete unit and then weigh? I would assume the stock pin would not be reusable once pressed out and are new ones available even?

As long as I can use pump gas I am good with 9.5 C/R if it livens up the motor. Do not really want to deck the block though unless there is something wrong with it. How far can you go with the head alone? I would guess .060 or is there something else involved here such as head cc?

I have been reading some on piston knurling and molycoating them for tightening up piston clearances with out reboring. Anyone play with these ideas? This is oldschool stuff, but I love it!

Thanks, George.

[ghcoe]

People are posting faster than I can write!

Yes, I will be installing a megasquirt injection system at a later date. I will also be upgrading to a Throttle position sensor type setup to get rid of the MAF system. Should clean up the airflow quite a bit.

George.

[RallyBob]

Originally Posted by ghcoe I was thinking that it should be pretty easy to source stock sized pistons and cheap. Most people rebore their motors and there is not much demand for stock sized pistons. If they do rebore their motors I would assume they would need their rods. Are the piston pins durable? I would not want some pin slap shortly after a engine install. I would assume the stock pin would not be reusable once pressed out and are new ones available even?

If you are intent on buying new pistons, then they come with new pins typically. I was under the impression you were going to grab some rods and pistons from an older (pre-71) block. I may have misunderstood. But stock bore new pistons are pretty rare since these cars are so old, the blocks have pretty much all worn to an extent and must be rebored.

Can the piston/rods be rebored to a common pin and just weigh each item separately or is it better to assemble complete unit and then weigh?

Balancing will normally involve matching the piston weights individually. The rods are balanced separate from the piston, and they are balanced end-to-end on a special fixture. So the pistons cannot be attached when this is done.

As long as I can use pump gas I am good with 9.5 C/R if it livens up the motor. Do not really want to deck the block though unless there is something wrong with it. How far can you go with the head alone? I would guess .060 or is there something else involved here such as head cc?

9.5:1 should be fine for pump gas assuming everything is tuned correctly. I have milled heads as much as .105", but I don't recommend it! For racing I'll go .080"-.085". For street I will go .025"-.050", depending on the application. Heavy milling is best reserved for racing classes where the rules say you must use stock pistons, and you have no other way to gain compression. Lessor degrees of milling are okay for 'fine tuning' the compression ratio and the quench area. But remember the more you mill the first time, the less you can mill in subsequent rebuilds over time!

I have been reading some on piston knurling and molycoating them for tightening up piston clearances with out reboring. Anyone play with these ideas? This is oldschool stuff, but I love it! Thanks, George.

A lot of 'old school' machinists still have the equipment to do knurling and still do it regularly...especially on older engines where piston availability is not so good, and diesels where the price for new pistons is VERY costly. The newer moly coatings can be applied pretty heavily I understand, although I have yet to try it out. Supposedly they can build up the skirts by .005" or so! That would make up for a lot of wear.

[wrench459]

Originally Posted by ghcoe People are posting faster than I can write! Yes, I will be installing a megasquirt injection system at a later date. I will also be upgrading to a Throttle position sensor type setup to get rid of the MAF system. Should clean up the airflow quite a bit. George.

A map sensor will work better than an tps as long the cam is kept mild.
Maybe I need to reword this reply.
The 75 had a simple throttle switch like you said. Idle contacts or wot contacts. A true tps is much needed.
The air flow meter is lacking ...I'm wondering if you could use a two wire MAF sensor for the proper input?
I believe the megasquirt supports both map and tps(Alpha-N) speed density fuel injection.
Just a ramble of thoughts....

[ghcoe]

Originally Posted by wrench459 A map sensor will work better than an tps as long the cam is kept mild. Maybe I need to reword this reply. The 75 had a simple throttle switch like you said. Idle contacts or wot contacts. A true tps is much needed. The air flow meter is lacking ...I'm wondering if you could use a two wire MAF sensor for the proper input? I believe the megasquirt supports both map and tps(Alpha-N) speed density fuel injection. Just a ramble of thoughts....

Yes it supports both. Problem with the MAF is a big cam will make it flutter at idle and cause erratic signals to the brian. Plus the door causes air restrictions and air turbulence in the intake. These Opel's had a round about way to get the air from the front of the car to the plenum, looking to get rid of that too with a TPS.

The plus side of a MAF is that as the engine wears it will compensate fuel flows. Air speed density will not.

George.

[wrench459]

I've got an '03 caravan in the shop...simple speed density system.
The beepin thing is stuck in e-85 mode so its flooding like you would not believe.

No adaptive fuel yeah right.

This bugger bear use's b1s1 and the lack of switching to figure out the fuel input. Most cars use a fuel identifier.

[RallyBob]

Originally Posted by RallyBob In truth it's pretty easy to do. I modified the cam gear for my 'stock' 2.2 last night, it took less than 5 minutes to do on a drill press. I'm not even going to check the cam timing when I assemble the engine. I did some quick figuring based on how much the head was milled (cam is retarded by about 2.5 degrees) and stuck in a 4° bushing...good enough for me! A little bit of advance is preferable for street driving.

To clarify how simple it was to modify the stock cam gear for advance/retard bushings, here's a couple of pics. Basically the mounting holes were enlarged slightly to allow for some gear rotation, and the hole for the alignment dowel was enlarged to fit the bushing. Keep in mind the hole is drilled from the back side of the gear, and it not drilled all the way through. This retains the bushing against the cam face when the gear is bolted in place.

The set of five bushings cost about $15, and I used one drill bit to drill all the holes to size. Total time invested was about 10 minutes. It's so easy, a caveman can do it....

[markandson]

Originally Posted by RallyBob To clarify how simple it was to modify the stock cam gear for advance/retard bushings, here's a couple of pics. Basically the mounting holes were enlarged slightly to allow for some gear rotation, and the hole for the alignment dowel was enlarged to fit the bushing. Keep in mind the hole is drilled from the back side of the gear, and it not drilled all the way through. This retains the bushing against the cam face when the gear is bolted in place. The set of five bushings cost about $15, and I used one drill bit to drill all the holes to size. Total time invested was about 10 minutes. It's so easy, a caveman can do it....

Bob,
Is the size of the enlarged mounting holes critical so that you still have the side of the bolt bearing on the side of the hole? Just curious.

[markandson]

Since MegaSquirt has a built in MAP sensor there is no problem doing what you want to do. The TPS that I used came from a 2.4 manifold that I got from RallyBob. I would think that some BMW's of the same era would have a usable TPS. MegaSquirt has a very simple system of setting up WOT and Closed Throttle positions and the amount of electrical resistance in the TPS does not matter, almost anything will work.

[wrench459]

Originally Posted by RallyBob The set of five bushings cost about $15, and I used one drill bit to drill all the holes to size. Total time invested was about 10 minutes. It's so easy, a caveman can do it....

I was just at summit this weekend. The offset bushings cost under 7.50 with tax. Comp cam #4760 for the even set.

I'm also running a sbc cam bolt locking plate for some extra insurance.

ugh me thinks it works ood :-)

[BQS4]

Originally Posted by RallyBob It's so easy, a caveman can do it....

Must... resist... temptation... to attach picture.....

[opelgtguy]

Originally Posted by BQS4 Must... resist... temptation... to attach picture.....

Uh ... part of a family portrait Gene

[RallyBob]

Originally Posted by markandson Bob, Is the size of the enlarged mounting holes critical so that you still have the side of the bolt bearing on the side of the hole? Just curious.

Not really, the offset bushing takes the thrust loads, and the center hole locates the gear. Once the bolts are tightened down I've never had one move on me. Make the holes big enough for a worst case scenario (for example, using the 8° bushing), and you're all set.

[RallyBob]

Originally Posted by wrench459 I was just at summit this weekend. The offset bushings cost under 7.50 with tax. Comp cam #4760 for the even set.

Good to know, the Mr Gasket ones are $15.95!

[ghcoe]

Originally Posted by RallyBob Not really, the offset bushing takes the thrust loads, and the center hole locates the gear. Once the bolts are tightened down I've never had one move on me. Make the holes big enough for a worst case scenario (for example, using the 8° bushing), and you're all set.

What size bit have you been using for making the holes bigger?

[wrench459]

Originally Posted by ghcoe What size bit have you been using for making the holes bigger?

See this thread post #21
http://www.opelgt.com/forums/opel-en...cked-head.html

The thread is a must read theres some dang good info from some gearheads.

[kwilford]

Originally Posted by wrench459 See this thread post #21 http://www.opelgt.com/forums/opel-en...cked-head.html The thread is a must read theres some dang good info from some gearheads.

And while you are at it, I believe that there is some useful information to be read in posts #39 through #43

[wrench459]

Originally Posted by kwilford And while you are at it, I believe that there is some useful information to be read in posts #39 through #43

Yep Keith your one of the gearheads.

[ghcoe]

Yup, read through that one a couple of times. Think I just did not see or forgot that I read that. Too much info for a caveman.

[grslightng02]

GHCOE, Are you sold on having exclusively an Opel motor? I would suggest you consider what our late friend Ron De Lozier did with the 3.4L V6.

You can read about them here:
Performance Articles - The Classic Opel Forums

Although I would suggest the Generation II 3800 3.8L Supercharged V6 with 205HP, 19/28 miles per gallon. These motors can be found in 1996-2002 Camaro's and Firebirds (for rear wheel drive) and parts are abundant.

I've found examples on craigslist of these motors from $500-1,000